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  • Artikel  (216)
  • Crystal structure  (86)
  • Holocene
  • Nitrogen fixation
  • nitrogen
  • Springer  (216)
  • 1995-1999  (216)
  • Geologie und Paläontologie  (173)
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  • Artikel  (216)
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  • 1
    Digitale Medien
    Digitale Medien
    Crystal structure of tetrakisdiphenylammonium hexadecachlorotetrabismuthate(III) (1995)
    Springer
    Journal of chemical crystallography 25 (1995), S. 841-844 
    Details
    ISSN: 1572-8854
    Schlagwort(e): Crystal structure ; bismuth chloride complexes ; diphenylammonium
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Physik
    Notizen: Abstract [(C6H5)2NH2]4 +[Bi4Cl16]4− crystallizes in the triclinic space group $$P\bar 1$$ witha=11.835(2),b=12.393(2),c=12.625(3)Å, α=108.37(3), β=108.69(3), γ=96.00(3)° andD c=2.135 g cm−3 forZ=1. The [Bi4Cl16]4− anion is a centrosymmetric cluster of four distorted edge-sharing BiCl6 octahedra. The ranges of the Bi−Cl bonds are 2.484(4)–2.606(3)Å for Bi−Cl(terminal), 2.691(3)–2.956(4)Å for Bi-Cl(µ2), and 2.960(3)–3.120(4)Å for Bi-Cl(µ3). The cations and anions are held in place by weak hydrogen bonds.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01671080
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  • 2
    Digitale Medien
    Digitale Medien
    Crystal structure of a bulky cyclic sulfite (1995)
    Springer
    Journal of chemical crystallography 25 (1995), S. 215-218 
    Details
    ISSN: 1572-8854
    Schlagwort(e): Crystal structure ; cyclic sulfite ; pentacycloundecane-8 ; 11-dione
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Physik
    Notizen: Abstract The structure of the cyclic sulfite derived from the reaction of thionyl chloride withendo-8-hydroxy-exo-8-(endo-8′-hydroxypentacyclo[5.4.0.0.2,6.03,10.05,9]undec-exo-8′-yl)pentacyclo-[5.4.0.0.2,6.03,10.05,9]undecane is reported. All bond lengths and angles are consistent with the strained cage geometry. A static disorder of the terminal oxygen was found to be present.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01665171
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  • 3
    Digitale Medien
    Digitale Medien
    Structure of the pinacol formed via sodium-promoted reductive dimerization of 12-methyleneheptacyclo-[6.6.02,6.03,13.04,11.05,9.010,14]tetradecan-7-one (1995)
    Springer
    Journal of chemical crystallography 25 (1995), S. 417-420 
    Details
    ISSN: 1572-8854
    Schlagwort(e): Crystal structure ; pinacol ; reductive dimerization
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Physik
    Notizen: Abstract The pinacol resulting from sodium promoted reductive coupling of a methyleneheptacyclo-[6.6.02,6.03,13.04,11.05,9.010,14]tetradecanone possesses a conformation in which equivalent groups on the pinacol carbon are virtually perpendicular to each other. This rotation minimizes steric interactions, thus the geometries of all the fragments in the molecule are within expected values.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01665280
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  • 4
    Digitale Medien
    Digitale Medien
    Crystal and molecular structure of 1-vinyl-3-methyl-imidazolium iodide, C6H9N2I (1995)
    Springer
    Journal of chemical crystallography 25 (1995), S. 601-603 
    Details
    ISSN: 1572-8854
    Schlagwort(e): Crystal structure ; imidazolium ; vinyl
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Physik
    Notizen: Abstract The title compound crystallizes with two independent molecules in the unit cell. The two molecules arecis-trans isomers. Crystal data: orthorhombic, P212121,a=7.0417(6),b=9.5341(9),c=25.411(2) Å,Z=8. The crystal structure has been solved by automated Patterson methods and refined toR=0.024 for 1843 observed reflections.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01667031
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  • 5
    Digitale Medien
    Digitale Medien
    Molecular structure of 3-(3-oxo-bicyclo[2.2.1]hept-5-en-2-yl)-oxirane-2-carboxylic acid methyl ester (1996)
    Springer
    Journal of chemical crystallography 26 (1996), S. 81-84 
    Details
    ISSN: 1572-8854
    Schlagwort(e): Crystal structure ; epoxy ester
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Physik
    Notizen: Abstract The crystal and molecular structure of an epoxy ester is described. The structure has been solved by vector search methods and refined by least squares methods toR 1=0.0372 [I〉2σ(I)]. The structure consists of two independent molecules in the asymmetric unit. These molecules are chemically the same. Crystal data: C11H12O4, triclinic, space group $$P\bar 1$$ ,a=10.324(3),b=10.553(7),c=10.869(5)Å, α=61.77(4), β=88.64(4), γ=88.16(6)°,V=1042.7(9)Å3,Z=4.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02018702
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  • 6
    Digitale Medien
    Digitale Medien
    Crystal structure of a highly hydrated tristrontium phosphate, Sr9(PO4)6·16H2O (1996)
    Springer
    Journal of chemical crystallography 26 (1996), S. 341-346 
    Details
    ISSN: 1572-8854
    Schlagwort(e): Crystal structure ; hydrated phosphate ; layer-type structure ; strontium phosphate ; strontium phosphate hydrate
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Physik
    Notizen: Abstract The crystal structure of a highly hydrated tristrontium phosphate, nonastrontium hexakis(phosphate) hexadecahydrate, Sr9(PO4)6·16H2O, has been determined by single crystal X-ray diffraction. The crystals are monoclinic,a=15.203(2),b=6.488(1),c=18.984(7) Å, β=98.42(2)o, space groupP2/c (No. 13),Z=2,V=1852.3 Å3,d c =2.951 Mg·m−3. The structure was refined by full-matrix least-squares techniques toR=0.038,R w =0.051, for 2329 reflections with I≥3σ(I). The structure can be described in terms of a layer-type arrangement parallel to (100). One layer consists of a compact assembly of columns of Sr and PO4 ions in a pseudohexagonal arrangement resembling an apatitic structure. A second layer containing all the water molecules and one PO4 ion that occupies the interstitial space may be referred to as the hydrated layer. The structure has an overall similarity to that of octacalcium phosphate and can be considered as a model for amorphous calcium phosphate.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01677098
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  • 7
    Digitale Medien
    Digitale Medien
    Molecular structure of [(tBu)2Al(μ-NHtBu)]2 (1996)
    Springer
    Journal of chemical crystallography 26 (1996), S. 563-567 
    Details
    ISSN: 1572-8854
    Schlagwort(e): Crystal structure ; aluminum ; amide
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Physik
    Notizen: Abstract The crystal and molecular structure of [(tBu)2Al(μ-NHtBu)]2 has been determined. The unit cell contains two independent molecules with only slight variation in the orientation of thetert-butyl ligands. Crystal data: Triclinic, $$P\bar 1$$ ,a=9.0138(6),b=10.2944(8),c=15.791(1) Å, α=91.262(6), β=89.822(6), γ=106.141(6)°,V=1407.2(2) Å3,Z=2,R=0.039,R w=0.041.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01668416
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  • 8
    Digitale Medien
    Digitale Medien
    Crystal structure of 5-(p-methoxyphenylamino)indane and AM1 calculations on N-arylamines derivatives, precursors of phenothiazine drugs (1998)
    Springer
    Journal of chemical crystallography 28 (1998), S. 735-739 
    Details
    ISSN: 1572-8854
    Schlagwort(e): Crystal structure ; diphenyl amines ; AM1 calculations ; phenothiazines
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Physik
    Notizen: Abstract The structural determination by X-ray crystallography of the titled N-arylamine 4a, as well as AM1 calculations on a series of derivatives (4b–c, 5a–c), are reported. The compound 4a is monoclinic P21/c with a = 7.656(3), b = 23.655(5), c = 7.686(9) Å, β = 112.59(6)°, V = 1285.2(2) Å3 and Z = 4. This structure has been used as a template for the building of some others derivatives used for AM1 calculations. The results show that the cyclization position on the aromatic rings, which can lead to two regioisomers, depends on the nature of the benzylic substituants.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1021860410863
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  • 9
    Digitale Medien
    Digitale Medien
    Synthesis, characterization, and X-ray crystal structure of di-(2,4-imidazolidinedione-5-ethyl)disulfide, C10H14N4O4S2 (1998)
    Springer
    Journal of chemical crystallography 28 (1998), S. 761-765 
    Details
    ISSN: 1572-8854
    Schlagwort(e): Crystal structure ; noncentrosymmetric ; disulfide ; imidazolidinedione ; homocystine hydantoin
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Physik
    Notizen: Abstract Di-(2,4-imidazolidinedione-5-ethyl)disulfide or homocystine hydantoin, C10H14N4O4S2 (I), crystallizes in the non-centrosymmetric space group P21 (No. 4) with two molecules in the unit cell with a = 7.132(1), b = 9.282(2), c = 10.770(2) Å and β = 105.68(1)°. The two imidazolidinedione rings are planar with a dihedral angle of 46.9°. The rings are joined by a diethyl disulfide bridge at chiral centers on the rings. The C-S-S-C torsion angle is −80°(−sc). The absolute stereochemistry of the chiral centers was determined to be (5S, 5′S), η = + 0.92 (11). Important bond distances include: S-S = 2.022(4); S-C (mean) = 1.809(8); and C=O (mean) = 1.224(7) Å. The compound is stabilized by a network of intermolecular carbonyl-to-amine hydrogen bonding and van der Waals cohesive forces.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1021816628610
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  • 10
    Digitale Medien
    Digitale Medien
    Crystal structure of a macrocyclic tetraamine isocyanato zinc(II) complex (1998)
    Springer
    Journal of chemical crystallography 28 (1998), S. 831-834 
    Details
    ISSN: 1572-8854
    Schlagwort(e): Crystal structure ; macrocyclic tetraamine ; isocyanato zinc(II) complex
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Physik
    Notizen: Abstract The complex, [Zn(L)(NCO)]Cl · 3H2O (1) (L = 3,14-dimethyl-2,6,13,17-tetraazatricyclo[14,4,01.18,07.12]docosane), has been synthesized and structurally characterized. 1 crystallizes in the monoclinic system, space group P21/n with a = 10.530(3), b = 9.315(2), c = 27.188(3) Å, β = 92.58(1)°, V = 2664.1(9)Å3, and Z = 4. The zinc atom is in a distorted squarepyramidal environment with the four nitrogen atoms of the macrocycle and one nitrogen atom of the isocyanate ligand.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1021831921283
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  • 11
    Digitale Medien
    Digitale Medien
    Synthesis and crystal structure of macrocyclic nickel(II) complex bridged by chromate (1998)
    Springer
    Journal of chemical crystallography 28 (1998), S. 867-870 
    Details
    ISSN: 1572-8854
    Schlagwort(e): Crystal structure ; macrocyclic nickel(II) complex ; chromate
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Physik
    Notizen: Abstract A novel compound catena-(μ-CrO4-O,O′)[Ni(L1)Ni(L2)] 3H2O (1) (L1 = 3,5,10,12-tetramethyl-1,4,8,11-tetraazacyclotetradecane and L2 = 2,5,9,12-tetramethyl-1,4,8,11-tetraazacyclotetradecane) has been synthesized for the first time and structurally characterized. 1 crystallizes in the triclinic space group Pī with a = 9.623(1), b = 10.084(1), c = 12.723 (3) Å, α = 66.74(2), β = 75.20(1), γ = 72.02(1)°, V = 1066.2(3) Å3, and Z = 2. The coordination environment around the Ni(II) ions is an axially elongated octahedron with the secondary amines of the isomeric ligands and two oxygen atoms of [CrO4]2−.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1022890217250
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  • 12
    Digitale Medien
    Digitale Medien
    Synthesis, characterization, peripheral studies, and structural analysis of E-4-(N-methylanilino)-3-pentene-2-one, C12H15NO (1998)
    Springer
    Journal of chemical crystallography 28 (1998), S. 899-903 
    Details
    ISSN: 1572-8854
    Schlagwort(e): Crystal structure ; ir/nmr ; β-amino-α ; β-unsaturaled ketone ; noncentrosemmtric ; enamino ketones
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Physik
    Notizen: Abstract Crystallographic structural refinement of E-4-(N-methylanilino)-3-pentene-2-one (I) has been carried out by means of three-dimensional single-crystal X-ray diffractometry. The title compound crystallizes in space group C2 (No. 5,Z = 4). The lattice constants are a = 21.543(4), b = 6.433(1), c = 8.019(2) Å, and β = 97.82(3)°. Characterizations include physical property determinations and spectrometric identifications employing IR, 1H and 13C NMR, and X-ray powder analyses. The molecules in the crystal lattice are held together by van der Waals forces. Selected bond distances and angles are presented and discussed as well as synthesis and peripheral studies.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1022802619976
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  • 13
    Digitale Medien
    Digitale Medien
    The structure of N-(1H-benzo[d]imidazol-2-ylmethyl)-N-(2,6-dichlorophenyl)amine (1998)
    Springer
    Journal of chemical crystallography 28 (1998), S. 145-147 
    Details
    ISSN: 1572-8854
    Schlagwort(e): Crystal structure ; benzimidazole ; antimicrobial activity
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Physik
    Notizen: Abstract The N-(1H-benzo[d]imidazol-2-ylmethyl)-N-(2,6-dichlorophenyl)amine, C14H11N3Cl2, M r = 292.17, crystallizes in the orthorhombic space group Pbca with unit cell parameters a = 10.707(2), b = 9.615(2), c = 25.944(6) Å. The benzimidazole ring system is planar and makes a dihedral angle of 77.8(1)° with the phenyl ring. The structure is stabilized by an N–H···N hydrogen bond.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1022497931783
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  • 14
    Digitale Medien
    Digitale Medien
    Synthesis and structural characterization of a novel polymeric praseodymium(III) complex with a new flexible double betaine (1998)
    Springer
    Journal of chemical crystallography 28 (1998), S. 177-183 
    Details
    ISSN: 1572-8854
    Schlagwort(e): Crystal structure ; coordination polymer ; praseodymium(III) carboxylate complex ; double betaine
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Physik
    Notizen: Abstract A novel polymeric Pr(III) complex with a new double betaine, namely [{Pr(L1)1.5(H2O)2} n ][ClOli4]3 n ·nH2O (1) (L1 = 1,4-diazoniobicyclo[2,2,2]octane-1,4-dipropionate), has been synthesized and characterized by X-ray analysis. In the title complex, the Pr(III) atom is nine-coordinated by seven oxygen atoms from five L1 ligands and two aqua ligands. Each pair of adjacent praseodymium(III) atoms is linked by a pair of μ3 chelating and bridging carboxylate groups, thus forming an infinite metal···metal chain running parallel to the a direction, and such chains are cross-linked by flexible backbones of L1 ligands into a three-dimensional network with the perchlorate anions and lattice water molecules accommodated in the interstitial space. The title complex crystallizes in the monoclinic space group P21/n with a = 8.085(2), b = 14.316(3), c = 29.775(6) Å, β = 103.04(3)° and Z = 4.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1022414109261
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  • 15
    Digitale Medien
    Digitale Medien
    Crystal structures of three substituted pentacyclo[5.4.0.02,6.03,10.05,9]undecanes (1998)
    Springer
    Journal of chemical crystallography 28 (1998), S. 251-258 
    Details
    ISSN: 1572-8854
    Schlagwort(e): Crystal structure ; pentacycloundecane
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Physik
    Notizen: Abstract The crystal structures of three compounds formed via ultimate nucleophilic attack of unsaturated hydrocarbon fragments are reported. Geometries of the bis(vinyl)-, mono(vinyl), and bis(ethynyl)-substituted PCU species are unexceptional. The crystal structures are dictated by the availability of intermolecular hydrogen bonding.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1021893001351
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  • 16
    Digitale Medien
    Digitale Medien
    Molecular structure and absolute configuration of (+)-(1R, 2S, 6R, 7S, 1′R)-5-(1′-phenylethylamino)-endo-tricyclo[5.2.1.02,6]deca-4,8-dien-3-one (1998)
    Springer
    Journal of chemical crystallography 28 (1998), S. 497-499 
    Details
    ISSN: 1572-8854
    Schlagwort(e): Crystal structure ; tricyclodecadienone ; enaminone ; resolution
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Physik
    Notizen: Abstract The crystal and molecular structure of (+)-(1R, 2S, 6R, 7S, 1′R)-5-(1′-phenylethylamino)-endo-tricyclo[5.2.1.02,6]deca-4,8-dien-3-one is described. Based on the known absolute configuration (R) of the α-phenylethylamine moiety the X-ray analysis revealed the absolute configuration of the title compound. The structure was refined to R 1 = 0.0298 for 1950 reflections (with I 〉 2σ(I)). Crystal data: C18H19NO, monoclinic, space group P21, a = 6.7406(4), b = 9.959(2), c = 11.3123(8)Å, β = 102.969(5), V = 740.0(2)Å3, and Z = 2.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1021733108852
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  • 17
    Digitale Medien
    Digitale Medien
    Molecular structure and absolute configuration of (−)-(1R, 2S, 6R, 7S, 2′S)-5-(2′-hydroxymethylpyrrolidin-1′-yl)-endo-tricyclo[5.2.1.02,6]deca-4,8-dien-3-one (1998)
    Springer
    Journal of chemical crystallography 28 (1998), S. 493-495 
    Details
    ISSN: 1572-8854
    Schlagwort(e): Crystal structure ; tricyclodecadienone ; enaminone ; dynamic kinetic resolution
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Physik
    Notizen: Abstract The crystal and molecular structure of (−)-(1R, 2S, 6R, 7S, 2′S)-5-(2′-hydroxymethyl-pyrrolidin-1′-yl)-endo-tricyclo[5.2.1.02,6]deca-4,8-dien-3-one is described. Knowing the absolute configuration of the prolinol moiety (S) the X-ray diffraction study established the absolute configuration of the title compound. The structure was refined to R 1 = 0.0322 for 1237 reflections (with I 〉 2σ(I)). Crystal data: C15H19NO2, monoclinic, space group P21, a = 6.0757(4), b = 11.3473(5), c = 9.5114(7)Å, β = 104.686(6)°, V = 634.32(7)Å3, and Z = 2.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1021781024782
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  • 18
    Digitale Medien
    Digitale Medien
    The crystal structure of 5α,9α-peroxyergosta-7,22-dien-6-one-3β-ol acetate (1998)
    Springer
    Journal of chemical crystallography 28 (1998), S. 239-241 
    Details
    ISSN: 1572-8854
    Schlagwort(e): Crystal structure ; ergosterol peroxide
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Physik
    Notizen: Abstract Ergosterol acetate, in pyridine, reacts with hydrogen peroxide and catalytic amounts of FeCl3 to afford the unusual product 5α,9α-peroxyergosta-7,22-dien-6-one-3β-ol acetate. The peroxide, in the title structure, is seen to bridge the C5 and C9 positions of the sterol backbone. Crystal data: C30H44O5, orthorhombic, P212121, a = 6.552(2), b = 11.048(8), c = 37.60(2), V = 2772(3)Å3, Z = 4.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1022486730643
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  • 19
    Digitale Medien
    Digitale Medien
    The crystal structure of hexabenzoylhexaazaisowurtzitane (1998)
    Springer
    Journal of chemical crystallography 28 (1998), S. 593-596 
    Details
    ISSN: 1572-8854
    Schlagwort(e): Crystal structure ; cage compound ; hexabenzoylhexaazaisowurtzitane
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Physik
    Notizen: Abstract The crystal and molecular structure of an interesting cage compound is described. Crystal data: C48H36N6O6·(CH3)2CO; monoclinic; space group: P2 1 /n; a = 14.948(3) Å, b = 15.079(3) Å, c = 19.539(4)Å, β = 93.93(3)°, V = 4394(2)Å3; and Z = 4.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1022452707772
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  • 20
    Digitale Medien
    Digitale Medien
    Structural study of the molecular complex in crystals of brucine with pantolactone (1999)
    Springer
    Journal of chemical crystallography 29 (1999), S. 121-125 
    Details
    ISSN: 1572-8854
    Schlagwort(e): Crystal structure ; brucine ; pantolactone ; molecular complex ; chiral resolution
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Physik
    Notizen: Abstract We have determined an X-ray crystal structure, a = 12.482(1), b = 14.349(1), c = 14.342(1) Å, orthorhombic, P212121 for a molecular complex of brucine with pantolactone. The crystal structure is composed of corrugated sheets of brucine molecules containing the guest pantolactone molecules. The conformational twist of the pyrrolidine ring in brucine may probably be important in projecting the amine N2 to provide a strong and specific binding site for a chiral complexation. The pseudo-equatorial orientation of the hydroxyl group of the pantolactone anchors itself for binding via hydrogen bonding. In the crystal packing, the pantolactone molecules form helices and the brucine molecules are attached to these helices by O=H···N hydrogen bonds.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1009543903373
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  • 21
    Digitale Medien
    Digitale Medien
    Effects of cosolvents cetyltrimethylammonium bromide on the thresholds for nucleation of nitrogen in aqueous solutions (1995)
    Springer
    Journal of solution chemistry 24 (1995), S. 1059-1073 
    Details
    ISSN: 1572-8927
    Schlagwort(e): Supersaturation ; nitrogen ; cosolvent ; cetyltrimethylammonium bromide
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Abstract The decomposition of ammonium nitrite in water creates a supersaturated solution of nitrogen. The same process occurs in water-organic solvent mixtures. Acetone, dioxane, dimethylsulfoxide (DMSO) and dimethylformamide (DMF) are the cosolvents used in this study. The limits of supersaturation of nitrogen (C SL /mol L−1) were determined in all of these solvent mixtures by releasing the dissolved gas sonicationally and measuring the volume of released gas. C SL was generally increased in the presence of cosolvents. The effectiveness sequence of organic solvents was found to be as DMF〈DMSO〈Dioxanet≅Acetone. Transportation period of small bubbles formed during sonication is changed by compositions of solvent mixtures. These periods may depend on the viscosity of the solution. Effects of the presence of cetyltrimethylammonium bromide were also studied. It was concluded that there may be a relation between the strength of the watercosolvent H-bonds and C SL and all of the measured quantities of this study were generally affected by micelle formation.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00973522
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  • 22
    Digitale Medien
    Digitale Medien
    Highly stereoselective sodium borohydride promoted reduction ofendo-5-acetyl-1,2,3,4-tetrachloro-7,7-dimethoxynorborn-2-ene (1995)
    Springer
    Journal of chemical crystallography 25 (1995), S. 657-660 
    Details
    ISSN: 1572-8854
    Schlagwort(e): Crystal structure ; norbornene ; stereoselective reduction
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Physik
    Notizen: Abstract Racemicendo-5-acetyl-1,2,3,4-tetrachloro-7,7-dimethoxynorborn-2-ene was stereoselectively reduced by sodium borohydride to give only theS,S orR,R diastereomers. The crystal structure of the product displays no unusual features.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01665972
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  • 23
    Digitale Medien
    Digitale Medien
    Structure of 2-acetoxy-1,2-di(1-adamantyl)ethanone (1995)
    Springer
    Journal of chemical crystallography 25 (1995), S. 291-294 
    Details
    ISSN: 1572-8854
    Schlagwort(e): Crystal structure ; 1,2-di(1-adamantyl)ethene
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Physik
    Notizen: Abstract The structure of 2-acetoxy-1,2-di(1-adamantyl)ethanone is reported. The steric requirements of the two adamantyl groups affect the structure in three ways—a slight elongation of the central bond, a small expansion of the angles about the central bond, and a conformation in which the C(sp2)-connected adamantyl group virtually bisects the large substituents attached to the sp3 carbon.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01796052
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  • 24
    Digitale Medien
    Digitale Medien
    Structure of a PCU-derived pinacol formed via sodiumpromoted reductive dimerization of pentacyclo[5.4.0.02,6.03,10.05,9]undecane-8,11-dione monoethylene ketal (1995)
    Springer
    Journal of chemical crystallography 25 (1995), S. 517-520 
    Details
    ISSN: 1572-8854
    Schlagwort(e): Crystal structure ; pinacol ; reductive dimerization
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Physik
    Notizen: Abstract The pinacol resulting from sodium promoted reductive coupling of pentacyclo[5.4.0.02,6.-03,10.05,9]undecane-8,11-dione monoethylene ketal possesses a conformation, dictated by intramolecular hydrogen bonding, that lies midway between eclipsed and staggered. The C−C and C−O distances in the pinacol unit are, respectively, longer and shorter than usual, and all parameters are as expected.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01665710
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  • 25
    Digitale Medien
    Digitale Medien
    Crystal and molecular structure determination, TGA-DTA, and infrared and Raman spectra of rubidium nitroprusside, Rb2[Fe(CN)5NO] (1996)
    Springer
    Journal of chemical crystallography 26 (1996), S. 325-330 
    Details
    ISSN: 1572-8854
    Schlagwort(e): Crystal structure ; rubidium nitroprusside ; IR ; Raman ; thermal analysis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Physik
    Notizen: Abstract The title compound, Rb2[Fe(CN)5NO], crystallizes in the space group P212121, witha=5.687(1),b=15.956(2),c=12.645(3) Å, andZ=4. Anions are in equivalent C1 sites (one per asymmetric unit) and are slightly distorted octahedra (C4v ideal symmetry). TGA and DTA curves and vibrational (infrared and Raman) spectra of Rb2[Fe(CN)5NO] were obtained. Results are interpreted in view of the crystal structure of the compound and the behavior of related substances.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01677095
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  • 26
    Digitale Medien
    Digitale Medien
    Thermodynamic vs. kinetic control in the Diels-Alder cycloaddition of cyclopentadiene to 2,3-dicyano-p-benzoquinone (1996)
    Springer
    Journal of chemical crystallography 26 (1996), S. 281-286 
    Details
    ISSN: 1572-8854
    Schlagwort(e): Crystal structure ; cyclopentadiene ; 2,3-dicyano-p-benzoquinone ; Diels-Alder reaction
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Physik
    Notizen: Abstract Diels-Alder cycloaddition of cyclopentadiene (1a) to 2,3-dicyano-p-benzoquinone (2a), when performed in methanol solvent at ambient temperature, proceeds with kinetic control to afford 1α,4α,4aβ,8aβ-tetrahydro-5,8-dioxo-1,4-methanonaphthalene-4a,8a-dicarbonitrile (7, 77% yield). However, when this cycloaddition is performed by refluxing an equimolar solution of1a and2a in benzene for 3 h, the product of thermodynamic control, i.e., 1α,4α,4aα,8aα-tetrahydro-5,8-dioxo-1,4-methanonaphthalene-6,7-dicarbonitrile (3a) is obtained in 64% yield. The structure of3a was confirmed by an analysis of the reduced intramolecular photocyclization product,9.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01677782
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  • 27
    Digitale Medien
    Digitale Medien
    Crystal and molecular structure of (2E,4S,10R)-4-hydroxy-2-undecen-10-olide (nor-patulolide C), C11H18O3 (1996)
    Springer
    Journal of chemical crystallography 26 (1996), S. 305-308 
    Details
    ISSN: 1572-8854
    Schlagwort(e): Crystal structure ; undecen-olid ; nor-patulolide
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Physik
    Notizen: Abstract The stereogeometry and absolute configuration of the title compound has been proved by an X-ray diffraction analysis. Crystal data: monoclinic, P21,a=7.7976(2),b=7.8288(2),c=8.9791(4) Å, β=90.331(4)o, Z=2. The crystal structure has been solved by vector search methods and refined toR=0.042 for 1798 observed reflections.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01677787
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  • 28
    Digitale Medien
    Digitale Medien
    Crystal and molecular structure of diphenylphosphinylacetic acid (1996)
    Springer
    Journal of chemical crystallography 26 (1996), S. 361-364 
    Details
    ISSN: 1572-8854
    Schlagwort(e): Crystal structure ; carboxylic acid ; phosphine oxide ; hydrogen bonding
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Physik
    Notizen: Abstract Diphenylphosphinylacetic acid crystallizes in the monoclinic space groupP2l/n with unit cell dimensionsa=5.6875(7),b=17.049(4),c=13.471(2) Å, β=93.36(1)° and Z=4. The molecular packing consists of hydrogen bonded chains arising from intermolecular interactions between a carboxylic acid hydroxyl group and an oxygen of an adjacent phosphine oxide moiety.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01677101
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  • 29
    Digitale Medien
    Digitale Medien
    Tetracyclo[6.3.0.04,11.05,9]undecane-2,7-dione (1996)
    Springer
    Journal of chemical crystallography 26 (1996), S. 425-428 
    Details
    ISSN: 1572-8854
    Schlagwort(e): Crystal structure ; tetracyclo[6.3.0.04,11.05,9]undecane-2,7-dione
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Physik
    Notizen: Abstract The compound crystallizes in the triclinic space group, $$P\bar 1$$ , witha=6.7702(4),b=7.0180(4),c=9.1960(7) Å, α=92.457(6), β=96.150(6), γ=93.444(5)°, andZ=2. The structure contains a rather short intramolecular H...H contact of 2.26(4) Å.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01665823
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  • 30
    Digitale Medien
    Digitale Medien
    Crystal structure of strontium potassium arsenate octahydrate (1998)
    Springer
    Journal of chemical crystallography 28 (1998), S. 741-746 
    Details
    ISSN: 1572-8854
    Schlagwort(e): Crystal structure ; hydrated ions ; ionic hydration ; strontium arsenate ; struvites ; struvite-type structure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Physik
    Notizen: Abstract The crystal structure of strontium potassium arsenate octahydrate, SrKAsO4·8H2O, has been determined by single crystal X-ray diffraction. The crystals are tetragonal, a = 7.144(1), c = 23.613(2) Å, space group I41md (No. 109), Z = 4, V = 1205.1(1) Å3, and d c = 2.258 g cm−3. All cations and anions in this compound are completely surrounded by water molecules. Sr2+ and K+ ions are each coordinated to eight water molecules arranged in an approximately square antiprism. The [Sr(H2O)8]2+ polyhedron shares one face of four water molecules with a [K(H2O)8]+ polyhedron forming O4-Sr-O4-K-O4 polyhedra. The O4-Sr-O4-K-O4 units are linked together through a pair of edge-sharing linkages of the outer water molecules, alternating along the a-axis and b-axis. The hydrated cation polyhedra appear to define the host lattice, which accommodates the AsO 4 3- ion in the interstitial space. The environment of the AsO 4 3- ion consists of 16 water molecules; each oxygen atom is the acceptor in hydrogen bonds from four water molecules. The pair distances associated with this environment may be used in investigations of the structure of hydrated 4 n- ions in solutions. Each water molecule is coordinated to one Sr and one K, and hydrogen bonded to two O atoms of two different AsO 4 3- ions. There is no hydrogen bonding between water molecules.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1021812527701
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  • 31
    Digitale Medien
    Digitale Medien
    Crystal structures of a series of 3,7-bis-(arylazo)-1,3,5,7-tetraazabicyclo[3.3.1]nonanes (1998)
    Springer
    Journal of chemical crystallography 28 (1998), S. 797-809 
    Details
    ISSN: 1572-8854
    Schlagwort(e): Crystal structure ; bicyclononane ; triazene ; bis-triazene ; nitrile substituent ; nitro substituent ; trifluoromethyl substituent ; hydrogen bonding
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Physik
    Notizen: Abstract The crystal and molecular structure of a series of 3,7-bis(arylazo)-1,3,5,7-tetraazabicyclo[3.3.1] nonanes (1a–d) have been determined by single crystal X-ray diffraction analysis. All four compounds have the same feature, that the tetraazabicyclononane unit assumes a cage-like structure with the aryltriazene moieties lying parallel to one another so that the aryl rings are held together by π – π stacking. Crystal data: 1a C17H18N10O4, triclinic, space group P − 1, a = 9.8899(10), b = 13.0845(13), c = 16.458(2) Å, α = 94.095(2)°, β = 107.004(2)°, γ = 111.027(2)°, V = 1863.5(3) Å3 and Z = 4; 1b, C19H18F6N8, orthorhombic, space group Pbca, a = 15.3210(8), b = 10.9512(6), c = 24.5698(13) Å, V = 4122.4(4) Å3 and Z = 8; 1c C19H18N10, monoclinic, space group P21/n a = 6.3742(6), b = 13.7343(13), c = 21.542(2)Å, β = 97.738(2)°, V = 1868.8(3) Å3, and Z = 4; 1d, C19H18N10, monoclinic, space group P21/c, a = 18.205(2), b = 17.398(2), c = 12.784(12) Å, β = 109.480(2)°, V = 3818.0(6) Å3, and Z = 8.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1021823619465
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  • 32
    Digitale Medien
    Digitale Medien
    Characterization and structural analyses of trimethoxy and triethoxybenzo[b]thiophene (1998)
    Springer
    Journal of chemical crystallography 28 (1998), S. 289-295 
    Details
    ISSN: 1572-8854
    Schlagwort(e): Crystal structure ; centrosymmetric ; methoxybenzo [b] thiophene ; estrogen receptor ; tubulin
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Physik
    Notizen: Abstract The crystal and molecular structures of two methoxybenzo [b] thiophenes have been determined by three-dimensional, single-crystal X-ray diffractometry. Both 3-(3′,4′,5′-trimethoxybenzoyl)-2-(4′-methoxyphenyl)-6-methoxybenzo[b]thiophene and 3-(3′,4′,5′-triethoxybenzoyl)-2-(4′-methoxyphenyl)-6-methoxybenzo[b]thiophene (hereafter referred to as I and II, respectively) crystallize in the triclinic centrosymmetric space group $$P \bar 1$$ (No. 2, C1) with two formula units per cell with a = 6.842(1) Å, b = 12.602(2) Å, c = 13.815(2) Å, α = 94.80(1)°, β = 98.27(2)°, and γ = 100.59(2)° and a = 10.600(1), b = 11.415(2), c = 12.137(2) Å, α = 94.57(1)°, β = 101.18(1)°, and γ = 110.45(1)°, respectively. The phase problems were solved by direct methods and the respective final full-matrix least-squares refinements converged to R = 0.039 and 0.068. The structures differ in the orientation of the trimethoxy and triethoxy groups of the benzoyl ligands. The molecules in the crystal lattice are held together by van der Waals forces. Selected bond distances, angles, and torsion angles are tabularized as well as reference to the synthesis of the title compounds and peripheral studies.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1021853320007
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  • 33
    Digitale Medien
    Digitale Medien
    Synthesis and crystal structure of a polymeric erbium(III)–sodium(I) coordination complex of picolinic acid N-oxide (1998)
    Springer
    Journal of chemical crystallography 28 (1998), S. 413-418 
    Details
    ISSN: 1572-8854
    Schlagwort(e): Crystal structure ; coordination polymer ; erbium(III)–sodium(I) carboxylate complex ; picolinic acid N-oxide
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Physik
    Notizen: Abstract A new Er(III)–Na(I) coordination polymer of stoichiometry [NaEr2L5(H2O)6(NO3)](NO3)·3.5H2O (HL = picolinic acid N-oxide) has been synthesized and characterized by single-crystal X-ray analysis. Crystals are triclinic, PĪ with a = 9.823(2), b = 12.453(2), c = 20.643(4) Å; α = 98.49(3), (β = 101.40(3), γ = 108.69(3)°; V = 2284(1) Å3; Z = 2. Of the two independent eight-coordinate erbium(III) ions in this complex, one is surrounded by four bidentate chelating L ligands, and the other by one bidentate chelating L ligand, four aqua ligands and two anti-carboxylate oxygen atoms from two neighboring [ErL4] units. The sodium(I) ion is in a distorted octahedral environment, being coordinated by a unidentate nitrate anion, three aqua ligands and two anti-carboxylate oxygen atoms from two adjacent [ErL4] units. The complex is built from zigzag chains of syn-anti carboxylate-bridged erbium(III) moieties directed in the a direction, which are cross-linked pairwise by aqua-bridgeddimericsodium(I) units. The resulting composite polymeric chains are further connected by hydrogen bonds to form a three-dimensional network.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1022424511580
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  • 34
    Digitale Medien
    Digitale Medien
    Crystal structure and two-stage hydrolysis of dimethoxo (meso-tetra(4-methoxyphenylporphyrinato))tin(IV), Sn(tmpp)(OMe)2 (1998)
    Springer
    Journal of chemical crystallography 28 (1998), S. 481-486 
    Details
    ISSN: 1572-8854
    Schlagwort(e): Crystal structure ; tin porphyrin ; two-stage hydrolysis ; methanolate ; trans equivalent axial ligand
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Physik
    Notizen: Abstract In this work, we determine the crystal structure of dimethoxo(meso-tetra(4-methoxyphenylporphyrinato))tin(IV), Sn(tmpp)(OMe)2 (1). Experimental results indicate that the tin atom has an octahedral geometry. The geometry around the tin center has Sn(1)–O(5) = 2.020(6), Sn(1)–O(6) = 2.003(7) Å and an average Sn(1)–N = 2.10(1) Å. The two methoxo groups are unidentately coordinated to the tin(IV) atom. Two-stage hydrolysis of Sn(tmpp)(OMe)2 in CDCl3 was observed by 1H and 13C NMR spectroscopy. Compound (1) crystallizes in the space group P21/n with a = 14.7492(1), b = 19.2022(3), c = 16.0806(2) Å, β = 94.104(1)°, and Z = 4.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1021776923873
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  • 35
    Digitale Medien
    Digitale Medien
    Synthesis and structural characterization of a novel polymeric gadolinium(III)–copper(II) complex of iminodiacetic acid (1998)
    Springer
    Journal of chemical crystallography 28 (1998), S. 475-479 
    Details
    ISSN: 1572-8854
    Schlagwort(e): Crystal structure ; coordination polymer ; gadolinium(III)-copper(II) complex ; iminodiacetic acid
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Physik
    Notizen: Abstract A novel polymeric Gd2Cu3 complex of iminodiacetic acid (H2L1=NH{CH2COOH}2), namely, Gd2Cu3(L1)6, 1, has been synthesized and structurally characterized. In the title complex, the Gd3+ ion is nine-coordinated by six O atoms from three bidentate chelating carboxylate groups and three O atoms from three anti-anti bridging carboxylic groups of six L1 ligands; the Cu2+ ion is six-coordinated by four O and two N atoms from two chelating L1 ligands. Each pair of Gd(III) atoms is bridged by three L1 ligands, each of which also chelates with one copper(II) ion, thus forming a Gd2Cu3 cluster unit. Such cluster units are cross-linked by flexible L1 ligands into a three-dimensional coordination framework. The title complex crystallizes in the trigonal space group P-3c1 (No. 165) with a = b = 13.433(4), c = 14.770(6) Å; V = 2308(1) Å3; Dcalca = 1.859 g cm−3; Z = 2.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1021724807035
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  • 36
    Digitale Medien
    Digitale Medien
    Structure of a deaza dimer of 4-methyl-3H-1,2,4-triazole-3,5(4H)-dione (1999)
    Springer
    Journal of chemical crystallography 29 (1999), S. 15-18 
    Details
    ISSN: 1572-8854
    Schlagwort(e): Crystal structure ; dimer ; triazole
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Physik
    Notizen: Abstract The title compound crystallizes in the monoclinic space group, P21/n; a = 9.0024(5), b = 5.8135(3), c = 15.2232(8) Å, β = 91.153(4)° Z = 4; and R = 0.050 based on 853 observed, unique reflections. The structure consists of two fused five-membered triazole rings, oriented relative to each other at 152°.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1009558912034
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  • 37
    Digitale Medien
    Digitale Medien
    Crystal structures of two substituted biphenyl derivatives: 5,5′-di t-butyl-2-2′-biphenyldiol and 5,5′-dimethyl-2,2′-biphenyldiol (1999)
    Springer
    Journal of chemical crystallography 29 (1999), S. 157-161 
    Details
    ISSN: 1572-8854
    Schlagwort(e): Crystal structure ; biphenyl ; mutual orientation ; strong H-bonds
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Physik
    Notizen: Abstract 5,5′-Di t-butyl-2,2′-biphenyldiol (I), C20H26O2, crystallizes in the orthorhombic space group P212121 with a = 18.243(2), b = 9.947(2), c = 9.685(3) Å, and Z = 4; 5,5′-dimethyl-2,2′-biphenyldiol (II), C14H14O2, crystallizes in the monoclinic space group P21/c with a = 9.959(2), b = 7.932(3), c = 15.392(2) Å, β = 105.43(2)°, and Z = 4. The aromatic rings are tilted by 52.7(1) and 43.8(1)° to each other in compounds (I) and (II), respectively. Strong intra- and inter-molecular H-bonds connect the molecules in the crystals.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1009509808535
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  • 38
    Digitale Medien
    Digitale Medien
    Synthesis, spectroscopic studies, and crystal structure of tris(tetra-n-butylammonium) hexakisisothiocyanatoindate(III) (1999)
    Springer
    Journal of chemical crystallography 29 (1999), S. 317-321 
    Details
    ISSN: 1572-8854
    Schlagwort(e): Crystal structure ; indium complexes ; isothiocyanate complexes ; octahedral coordination
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Physik
    Notizen: Abstract The reaction of a 1:10 molar ratio between indium chloride and tetra-n-butylammonium thiocyanate in ethanol affords the complex [(n-C4H9)4N]3[In(NCS)6] (1), the structure of which has been established by X-ray diffraction. This compound crystallizes in the cubic space group Pa3¯ with eight formula units in the unit cell. The formula unit consists of three separate cationic tetra-n-butylammonium groups and an independent hexakisisothiocyanatoindium anionic group. The six near linear thiocyanate ligands coordinate octahedrally through the nitrogen atom to the indium metal center. The coordination of the n-butyl groups to the ammonium-nitrogen atom is tetrahedral. The complex has also been characterized by IR, 1H and 13C NMR, physical properties, and X-ray powder analysis.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1009525918781
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  • 39
    Digitale Medien
    Digitale Medien
    Crystal structures of a series of 3,8-di[-2-aryl-1-azenyl]-1,3,6,8-tetraazabicyclo[4.4.1]undecanes (1999)
    Springer
    Journal of chemical crystallography 29 (1999), S. 145-156 
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    ISSN: 1572-8854
    Schlagwort(e): Crystal structure ; bicycloundecane ; triazene ; bis-triazene ; nitro substituent ; carboalkoxy substituent ; π–π stacking
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Physik
    Notizen: Abstract The crystal and molecular structure of a series of 3,8-di[-2-aryl-1-azenyl]-1,3,6,8-tetraazabicyclo[4.4.1]undecanes (1–5) have been determined by single crystal X-ray diffraction analysis. In all five compounds, the tetraazabicycloundecane portion of the molecule assumes a cage-like, folded structure with the aryltriazene moieties aligned approximately parallel; the structure is held in the folded configuration by either intramolecular or intermolecular π–π stacking forces. Crystal data: 1 C19H22N10O4, monoclinic space group P21/c, a = 10.1846(7), b = 9.9556(7), c = 20.819(2) Å, β = 98.725(1)°, V = 2086.5 (3) Å3, Z = 4; 2 C23H28N8O4, triclinic, space group Pī, a = 6.7064(7), b = 12.9662(14), c = 14.054(2) Å, α = 94.796(2), β = 91.621(2), γ = 104.836(2)°, V = 1175.7(2) Å3, Z = 2; 3 C19H22N10O4, monoclinic, space group P21/c, a = 14.237(2), b = 13.520(2), c = 11.5805(12) Å, β = 113.514(2)°, V = 2044.0(4) Å3, Z = 4; 4 C21H22N10, monoclinic, space group C2/c, a = 54.247(3), b = 11.5531(7), c = 12.9670(7) Å, β = 95.710(1)°, V = 8086.4(8) Å3, Z = 16; 5 C25H32N8 04, monoclinic, space group P21/c, a = 10.2908(7), b = 16.5687(12), c = 15.1662(10) Å, β = 94,188(1)°, V = 2579.0(3) Å3, Z = 4.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1009557724465
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  • 40
    Digitale Medien
    Digitale Medien
    Synthesis and crystal structure of 4,5-dibromo[2.1.1]triblattene (1999)
    Springer
    Journal of chemical crystallography 29 (1999), S. 351-354 
    Details
    ISSN: 1572-8854
    Schlagwort(e): Crystal structure ; dibromotriblattene
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Physik
    Notizen: Abstract Reaction of 4-bromopentacyclo[7.3.0.02,7.03,11.06,10]dodec-11-ene (1) with Br2—CCl4 afforded 4,4,5-tribromopentacyclo[7.3.0.02,7.03,11.06,10]dodecane (2) in 89–94% yield. Subsequent treatment of 2 with KOt-Bu-t-BuOH resulted in competitive elimination of the elements of HBr and of Br2 with concomitant formation of 4,5-dibromopentacyclo[7.3.0.02,7.03,11.06,10]dodec-11-ene (3, 76%) and 1 (17%), respectively. The structure of 3 was established unequivocally via application of X-ray crystallographic methods. Crystal data for 3: monoclinic, C2/c, a = 9.895(1), b = 9.0963(7), c = 12.471(1) Å, β = 106.875(8)°, z = 4.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1009538321507
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  • 41
    Digitale Medien
    Digitale Medien
    Structure of a C2-symmetric bis(benzyloxy)trishomocubanone (1995)
    Springer
    Journal of chemical crystallography 25 (1995), S. 747-750 
    Details
    ISSN: 1572-8854
    Schlagwort(e): Crystal structure ; trishomocubanone
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Physik
    Notizen: Abstract The structure of a bis(benzyloxy)trishomocubanone with molecular C2 symmetry reveals that substitution of benzyloxy groups has little effect on the trishomocubane cage.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01670329
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  • 42
    Digitale Medien
    Digitale Medien
    Crystal structure of ethyl 4-methylthio-3-phenyl-2-thioxo-2,3-dihydro-1,3-oxazole-5-carboxylate (1995)
    Springer
    Journal of chemical crystallography 25 (1995), S. 237-240 
    Details
    ISSN: 1572-8854
    Schlagwort(e): Crystal structure ; 1,3-oxazoline-2-thione ; resonance structures
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Physik
    Notizen: Abstract The title compound C13H13NO3S2 crystallizes in the triclinic space group $$P\bar 1$$ (Z=2) with lattice constantsa=8.382(2),b=10.042(2),c=10.134(2) Å, α=119.35(1)°, β=101.40(1)° and γ=90.54(1)°. The interplanar angle between the least squares planes of the 1,3-oxazoline ring and the phenyl ring amounts to 90.2°, thus hindering conjugation between the benzene and heterocyclic system. The observed bond parameters of the five-membered heterocycle suggest a significant contribution from a zwitterionic dipolar limiting structure [38.7(5)%] to the description of this ring system. The particular contributions of the resonance structures were estimated by calculations using the HOSE model on the base of the observed bond lengths.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01665176
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  • 43
    Digitale Medien
    Digitale Medien
    Synthesis and structure ofexo-11-cyano-endo-11-(trimethylsilyloxy)pentacyclo[5.4.0.02,6.03,10.05,9]undecan-8-one (1995)
    Springer
    Journal of chemical crystallography 25 (1995), S. 267-271 
    Details
    ISSN: 1572-8854
    Schlagwort(e): Crystal structure ; pentacycloundecan-8-one ; pentacycloundecane-8,11-dione
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Physik
    Notizen: Abstract The crystal structure of an asymmetric pentacyclo[5.4.0.02,6.03,10.05,9]undecan-8,11-dione derivative is reported, in which Me3SiCN has been added across one of the keto groups. The cage structure demonstrates the expected effects of this addition.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01665182
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  • 44
    Digitale Medien
    Digitale Medien
    Structure of the product formed via Cu(I)-promoted oxidative dimerization ofexo-8-ethynylpentacyclo[5.4.0.02,6.03,10.05.9]undecan-endo-8-ol (1995)
    Springer
    Journal of chemical crystallography 25 (1995), S. 543-547 
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    ISSN: 1572-8854
    Schlagwort(e): Crystal structure ; diyne ; oxidative dimerization
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Physik
    Notizen: Abstract The structure consists of two acetyl-substituted PCU cages linked by a diyne fragment. The conformation about the linker is midway between staggered and eclipsed, and the acetyl groups are somewhat distorted due to the proximity to the bulky cage units.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01667022
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  • 45
    Digitale Medien
    Digitale Medien
    Crystal structure oftrans-tetrachlorobis[2-(2-1H-imidazolyl)-1H-imidazolium]cadmium(II), [Cd(H3biim)2Cl4] (1996)
    Springer
    Journal of chemical crystallography 26 (1996), S. 695-699 
    Details
    ISSN: 1572-8854
    Schlagwort(e): Crystal structure ; 2,2'-bi-1H-imidazole ; cadmium chloride
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Physik
    Notizen: Abstract The reaction between cadmium(II) chloride and 2,2'-bi-1H-imidazole (H2biim) in an acidic solution affords [Cd(H3biim)2Cl4] (H3biim=2-(2-1H-imidazolyl)-1H-imidazolium) in 63% yield. The compound crystallizes in the triclinic space groupP1, wherea=8.072(2),b=8.100(2),c=8.593(2) Å, α=75.89(2), β=62.94(2), γ=63.29(1)°,V=446.4(2) Å3, andZ=1. The central Cd atom exhibits an octahedral geometry composed of a Cl4N2 core. The Cd-N bond distance is 2.392(2) Å. Cd−Cl distances are 2.5919(9) and 2.671(1) Å.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01991966
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  • 46
    Digitale Medien
    Digitale Medien
    X-ray structures of two methoxybenzo[b]thiophenes (1996)
    Springer
    Journal of chemical crystallography 26 (1996), S. 801-806 
    Details
    ISSN: 1572-8854
    Schlagwort(e): Crystal structure ; centrosymmetric ; methoxybenzo[b]thiophene ; estrogen receptor ; tubulin
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Physik
    Notizen: Abstract The crystal and molecular structures of two methoxybenzo[b]thiophenes have been determined by three-dimensional, single-crystal X-ray diffractometry. Both 3-(4′-hydroxy-3′, 5′-dimethoxybenzoyl)-2-(4′-methoxyphenyl)-6-methoxybenzo[b]thiophene and 3-(2′,6′-dimethoxybenzoyl)-2-(4′-methoxyphenyl)-6-methoxybenzo[b]thiophene (hereafter referred to asI andII, respectively) crystallize in the monoclinic centrosymmetric space groupP21/n (No. 14, C 2h 5 ) with four formula units-per cell witha=6.866(1),b=28.638(2),c=11.830(2) Å, and β=105.52(1)° anda=9.328(1),b=7.977(1),c=29.650(4) Å, and β=97.87(1)°, respectively. The phase problems were solved by direct methods and the respective final full-matrix least-squares refinements converged toR=0.046 and 0.031. The structures differ in the positioning of the dimethoxy groups of the benzoyl ligands and the addition of a hydroxyl group inI. The molecules in the crystal lattice are held together by van der Waals forces plus the addition of hydrogen bonding in compoundI. Selected bond distances and angles and torsion angles are tabularized.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01670312
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  • 47
    Digitale Medien
    Digitale Medien
    Reaction of vinylmagnesium bromide with hexacyclo[10.2.1.02,11.04,9.04,14.09,13]pentadeca-5,7-diene-3,10-dione: Transannular hemiketal formation (1996)
    Springer
    Journal of chemical crystallography 26 (1996), S. 429-433 
    Details
    ISSN: 1572-8854
    Schlagwort(e): Crystal structure ; hexacyclopentadeca-5,7-diene-3,10-dione
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Physik
    Notizen: Abstract Reaction between vinylmagnesium bromide and the cage dione leads to attack of only one equivalent of Grignard and intramolecular nucleophilic attack on the second ketone. The product compound crystallizes in the monoclinic space group, P21/a, witha=9.509(1),b=11.071(2),c=12.492(4) Å, β=104.32(2)°, andZ=4.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01665824
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  • 48
    Digitale Medien
    Digitale Medien
    The crystal and molecular structure of 6,8,15,16b,16c,17-hexahydro-16b,16c-diphenyl-7H,16H-6a,7a,15a,16a-tetraazanaphtho[5,6]azulano[2,1,8-ij]naptho[f]azulene-7,16-dione (1996)
    Springer
    Journal of chemical crystallography 26 (1996), S. 365-368 
    Details
    ISSN: 1572-8854
    Schlagwort(e): Crystal structure ; receptor ; clip shaped molecule
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Physik
    Notizen: Abstract The crystal and molecular structure of a clip containing molecule is described. The structure was solved by vector search methods and refined by least squares methods toR l=0.0768 [I〉2σ(I)]. Crystal data: C40H30N4O2·HCCl3, triclinic, space group $$P\bar 1$$ ,a=9.302(2),b=12.981(2),c=15.765(2)Å, α=65.91(2)°, β=76.40(2)°, γ=80.15(1)°,V=1682.9(4)Å3, Z=2.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01677102
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  • 49
    Digitale Medien
    Digitale Medien
    Synthesis and X-ray analysis of 1-((1S)-phenylethyl)-azetidine-(2R)-piperidinamide (1996)
    Springer
    Journal of chemical crystallography 26 (1996), S. 639-642 
    Details
    ISSN: 1572-8854
    Schlagwort(e): Crystal structure ; chiral auxiliaries
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Physik
    Notizen: Abstract The crystal and molecular structure of a new azetidine-2-carboxylic amide derivative is described. The structure was solved by direct methods and refined by least squares methods toR1=0.0393 for 4264 reflections (withI〉2σ(I)) The structure consists of two independent molecules which are chemically the same with slight differences in geometry. Crystal data: C17H24N2O, monoclinic, space groupP21,a=8.3782(4),b=20.0342(13),c=9.7769(8) Å, β=109.687(6)°,V=1545.1(2)Å3,Z=4.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01668624
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  • 50
    Digitale Medien
    Digitale Medien
    Crystal structures of two 1,2-bis-(1-aryl-3-methyltriazene-3-yl-)ethanes with aryl substituents of opposite polarity (1998)
    Springer
    Journal of chemical crystallography 28 (1998), S. 5-10 
    Details
    ISSN: 1572-8854
    Schlagwort(e): Crystal structure ; triazene ; bis-triazene ; nitrile substituent ; methoxy substituent ; hydrogen bonding
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Physik
    Notizen: Abstract The crystal and molecular structure of 1,2-bis-{1-(2-cyanophenyl)-3-methyltriazen-3-yl-}ethane (1) and 1,2-bis-{1-(2-methoxyphenyl)-3-methyltriazen-3-yl-}ethane (2) have been determined by single crystal X-ray diffraction analysis. Bis-triazene (1) exists as the “staggered” conformation in the solid state, with an anti-anti configuration around the N2–N3 bond of the triazene units, whereas 2 assumes a “gauche” conformation with the syn-syn configuration in the triazene units. Crystal data: 1 C18H18N8, triclinic, space group P −1, a = 6.108(2), b = 8.118(3), c = 9.600(4)Å, α = 101.37(7)°, β = 96.47(7)°, γ = 102.71(5)°, V = 449.1(3)Å3, Z = 2; 2 C18H24N6O2, monoclinic, space group P 21/n, a = 13.119(5), b = 7.745(2), c = 19.201(2)Å, β = 96.47(7)°, V = 1910.3(9)Å3, Z = 4.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1021714316063
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  • 51
    Digitale Medien
    Digitale Medien
    Crystal structures of the hydrated disodium and paraquat salts of 1,8-disulfonato-3,4,5,6-acridinetetracarboxylic acid (1998)
    Springer
    Journal of chemical crystallography 28 (1998), S. 39-46 
    Details
    ISSN: 1572-8854
    Schlagwort(e): Crystal structure ; 1,8-disulfonato-3,4,5,6-acridinetetracarboxylic acid ; 3,4,5,6-tetracarboxyacridine-1,8-disulfonate ; paraquat ; hydrate
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Physik
    Notizen: Abstract Two hydrated salts of 1,8-disulfonato-3,4,5,6-acridinetetracarboxylic acid, H2L, have been characterized by single-crystal X-ray analysis. Compound 1, Na2L·9 $$ - \frac{1}{2}$$ H2O, crystallizes in the monoclinic space group C2/c with a = 42.005(1), b = 6.838(1), c = 23.807 (1) Å, β = 122.71 (1)°, and Z = 8. Compound 2, (paraquat)L·2H2O, belongs to the triclinic space group $${P\bar 1}$$ with a = 9.940(1), b = 11.543(1), c = 14.033(1) Å, α = 105.45(1), β = 95.82(1), γ = 100.14(1)° and and Z = 2. All four carboxyl groups in the 3,4,5,6-tetracarboxyacridine-1,8-disulfonate dianion L2− are un-ionized. In 1 the distorted octahedrally coordinated sodium cations, the anions, and the lattice water molecules are joined together by hydrogen bonds to generate a three-dimensional network. In the crystal structure of 2, a host framework composed of L2− ions and water molecules accommodate the paraquat dications within two channel systems running parallel to the a and b axes.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1021726618789
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  • 52
    Digitale Medien
    Digitale Medien
    Crystal structures of four dibromomethylene-functionalized cage compounds (1998)
    Springer
    Journal of chemical crystallography 28 (1998), S. 259-266 
    Details
    ISSN: 1572-8854
    Schlagwort(e): Crystal structure ; heptacyclotetradecane ; hexacyclotetradecane
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Physik
    Notizen: Abstract Crystal structures of four dibromomethylene-functionalized hexa- and heptacyclotetradecane cages are reported. 7-(Dibromomethylene)heptacyclo[6.6.0.02,6.03,13.04,11.05,9.010,14]tetradecane (3): orthorhombic, Pnma, a = 14.744(1), b = 11.237(1), c = 7.4625(7) Å Z = 4; R = 0.0531 for 504 observed reflections. 7,12-Bis(dibromomethylene)heptacyclo[6.6.0.02,6.03,13-04,11 .05,9.010,14]tetradecane (4): monoclinic, I2/a, a = 11.257(1), b = 9.5844(8), c = 13.884(2) Å, β = 92.254(8)° Z = 4; R = 0.0413 for 663 observed reflections. 10,14-bis(dibromomethylene)hexacyclo[6.6.0.02,6.03,13.04,11.05,9]tetradecane (6): monoclinic, P21/n, a = 8.118(1), b = 15.273(4), c = 12.826(3) Å, β = 104.20(1)° Z = 4; R = 0.0384 for 1392 observed reflections. 14-(dibromomethylene)hexacyclo[6.6.0.02,6.03,13.04,11.05,9]tetradecan-10-one (7): monoclinic, P21/n, a = 8.2879(7), b = 15.273(1), c = 10.0565(9) Å, β = 92.271(8)° Z = 4; R = 0.0320 for 1402 observed reflections. The functional groups lead to slight shortening of bond lengths.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1021845118189
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  • 53
    Digitale Medien
    Digitale Medien
    A dinuclear cyano-bridged complex based on hexacyanoferrate(III) and samarium(III) nitrate: synthesis and crystal structure (1998)
    Springer
    Journal of chemical crystallography 28 (1998), S. 303-307 
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    ISSN: 1572-8854
    Schlagwort(e): Crystal structure ; samarium(III) complexes ; iron(III) complexes ; cyanide-bridges ; dinuclear complexes
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Physik
    Notizen: Abstract A new complex, [Sm(DMF)4(H2O)4Fe(CN)6]·H2O (DMF = N, N-dimethylformamide), has been synthesized and characterized by X-ray single crystal structure and thermogravimetric analyses. The complex crystallizes in the P21/n space group, with lattice parameters a = 17.583(4) Å, b = 8.870(2) Å, c = 19.845(6) Å, β = 95.98(3)°, V = 3078(1) Å3, D x = 1.679 Mg m−3, D m = 1.65(1) Mg m−3, Z = 4. The molecular structure shows that a cyano-bridged bimetallic structure is obtained. The Sm atom is coordinated by eight oxygen atoms of four water molecules and four DMF molecules and one nitrogen atom of the bridging cyanide ligand. The iron atom assumes approximately an octahedral environment surrounded by six CN ligands. The hydrate water molecule is hydrogen-bonded to one of the O atoms bound to Sm. Each terminal CN ligand of the Fe(CN) 6 3− entity is hydrogen-bonded to some O atoms of water molecules. An infrared spectrum is also reported.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1021857420915
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  • 54
    Digitale Medien
    Digitale Medien
    Gold(III)-pteridine compounds: synthesis, spectral, and X-ray diffraction studies on new adducts between sodium tetrabromoaurate(III) and lumazine derivatives (1998)
    Springer
    Journal of chemical crystallography 28 (1998), S. 565-570 
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    ISSN: 1572-8854
    Schlagwort(e): Crystal structure ; complexes ; pteridine ; lumazine
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Physik
    Notizen: Abstract In aqueous hydrobromic medium, Na[AuCl4] reacts with 1,3-dimethyllumazine (1,3-dimethyl-pteridine-2,4(1H,3H)-dione, DLM) or 1,3,6,7-tetramethyllumazine (DLMD) to give three adducts with simplified formulas Na[AuBr4](DLMD), Na[AuBr4](DLM), and Na[AuBr4](DLM)2. These compounds have been characterized by means of analytical techniques, and IR and NMR spectroscopies. Single-crystal x-ray diffraction studies have been made on the Na[AuBr4](DLM)2 compound. The crystals belong to the orthorhombic Pbca space group, with a = 15.249(1), b = 15.238(2), c = 21.563(2) Å, Z = 8, and R = 0.053. The structure consists of planar [AuBr4]− anions and Na+ cations weakly linked to two crystallographically independent DLM molecules. The Na+ cation interacts weakly with four oxygen and one nitrogen atoms from four different pteridine molecules, its environment may be described as a very distorted square pyramid.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1023252324268
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  • 55
    Digitale Medien
    Digitale Medien
    Molecular structure of AlH3[N(CH2CH2)3CH]2 (1998)
    Springer
    Journal of chemical crystallography 28 (1998), S. 649-651 
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    ISSN: 1572-8854
    Schlagwort(e): Crystal structure ; aluminum ; hydride ; complex ; quinuclidine
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Physik
    Notizen: Abstract Reaction of AlH3[N(CH2CH2)3CH] with hexamethyltrisiloxane, (OSiMe2)3, gives rise to the bis-quinuclidine complex AlH3[N(CH2CH2)3CH]2, which has been characterized by 1H and 13C NMR spectroscopy and X-ray crystallography. The molecular structure of AlH3[N(CH2CH2)3CH]2 consists of a trigonal bipyramidal aluminum with axial coordination of the quinuclidine ligands. Crystal data: orthorhombic, space group Pbcn, a = 10.6895(9), b = 12.266(1), c = 12.3794(9) Å, V = 1623.2(2) Å3, and Z = 4.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1022473312315
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  • 56
    Digitale Medien
    Digitale Medien
    Synthesis and crystal structure of a new lithium cyclohexaphosphate hydrate: Li6P6O18·10H2O (1999)
    Springer
    Journal of chemical crystallography 29 (1999), S. 323-327 
    Details
    ISSN: 1572-8854
    Schlagwort(e): Crystal structure ; cyclohexaphosphate ; hydrate
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Physik
    Notizen: Abstract The synthesis and crystal structure of a novel hydrate of lithium cyclohexaphosphate are reported. Li6P6O18·10H2O crystallizes in the space group C2/c with a = 15.113(5), b = 12.006(2), c = 15.892(2) Å, β = 122.85(2)°, and Z = 4. The structure consists of P6O18 ring layers stacked along the c direction in between which are located the lithiumions and water molecules. Two LiO4 tetrahedra share common edges with LiO5 pseudosquare pyramids to form two independant Li3O9 units. About 50% of the water molecules have fractional occupancy rates and form fragments of molecules. A linear relationship is established between the relative cell volume V/Z and the hydration degree, n, for all the known hydrates: Li6P6O18·nH2O.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1009577902852
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  • 57
    Digitale Medien
    Digitale Medien
    Synthesis and structure of a bis(ethynyl)-substituted oxahexacyclic cage ether (1999)
    Springer
    Journal of chemical crystallography 29 (1999), S. 347-349 
    Details
    ISSN: 1572-8854
    Schlagwort(e): Crystal structure ; pentacycloundecane ; triple bonds
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Physik
    Notizen: Abstract Intramolecular dehydration of a cage-diol results in the title compound. This crystallizes in the monoclinic space group P21/c; a = 8.6403(8), b = 9.5698(7), c = 14.062(1) Å β = 107.47(7)° and Z = 4.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1009586204669
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  • 58
    Digitale Medien
    Digitale Medien
    A cobalt(II) complex with the N,N,O-tridentate ligand 6-amino-5-formyl-1,3-dimethyluracilato-benzoyl-hydrazone (1999)
    Springer
    Journal of chemical crystallography 29 (1999), S. 283-286 
    Details
    ISSN: 1572-8854
    Schlagwort(e): Crystal structure ; complexes ; cobalt ; benzoylhydrazone
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Physik
    Notizen: Abstract The crystal structure of bis-(6-amino-5-formyl-1,3-dimethyluracilato benzoylhydrazone)cobalt(II) dimethylformamide solvate is described. This compound crystallizes in the triclinic system, space group P1¯, Z = 2 with a = 9.7368(8), b = 12.346(1), c = 17.184(1) Å, α = 78.372(6), β = 74.585(6), γ = 71.113(5)°, and V = 1869.0(3) Å3. The coordination polyhedron around the metal ion displays a slightly flattened M(NNO)2 octahedral shape. Both ligands bind in a trident fashion through the benzoylic oxygen atom, the hydrazone nitrogen atom closer to the uracil ring, and the deprotonated nitrogen atom of the amino group. The two ligands exhibit quite different conformations: one of them is almost planar, whereas the other is severely twisted.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1009565600126
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  • 59
    Digitale Medien
    Digitale Medien
    Simulation of kinetics of nitrogen desorption from Rh(111) (1996)
    Springer
    Catalysis letters 37 (1996), S. 163-165 
    Details
    ISSN: 1572-879X
    Schlagwort(e): nitrogen ; Rh(111) ; thermal desorption ; Arrhenius parameters ; lateral interactions ; NO decomposition
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Abstract Associative desorption of N atoms from the Rh(111) surface is simulated in the framework of the lattice-gas model. The Arrhenius parameters and nearest-neighbour lateral interaction employed to describe the measured thermal desorption spectra are as follows:v=1013 s−1,E d=40 kcal/mol, and ε1=1.7 kcal/mol. The results obtained are used to clarify the role of nitrogen desorption in the NO + CO reaction on Rh(111) atT=400–700 K andP NO≈P CO≈0.01 atm.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00807748
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  • 60
    Digitale Medien
    Digitale Medien
    The crystal structure of PbFe[AsO4][AsO3(OH)] (1996)
    Springer
    Monatshefte für Chemie 127 (1996), S. 127-133 
    Details
    ISSN: 1434-4475
    Schlagwort(e): PbFe[AsO4][AsO3(OH)] ; Synthesis,hydrothermal ; Crystal structure ; Crystal chemistry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Hellgrüne bis nahezu farblose Kristalle von PbFe[AsO4][AsO3(OH)] wurden unter niedrig-hydrothermalen Bedingungen synthetisiert (a=4.846(2),b=8.482(4),c=15.560(6) Å, β=92.82(3)°, Raumgruppe P21/n, Z=4). Für die Einkristall-Strukturbestimmung wurden 110 freie Parameter aufR=0.042,R w=0.031 verfeinert (1545 Röntgenbeugungsreflexe mitF 0 〉3σ(F 0) und sinϑ/λ⩽70°). Die Kristallstruktur wird durch eine dreidimensionale Ecken-Verknüpfung der FeO6-Oktaeder mit den Arsenattetraedern und den protonierten Arsenatgruppen charakterisiert. Jeweils zwei PbO7-Polyeder sind über eine Kante zu Pb2O12-Dimeren verknüpft, die in Zwischenräumen angeordnet sind.
    Notizen: Summary Light green to nearly colourless crystals of PbFe[AsO4][AsO3(OH)] were synthesized under moderate hydrothermal conditions (a=4.846(2),b=8.482(4),c=15.560(6) Å, β=92.82(3)°, space group P21/n, Z=4). For a single-crystal structure determination, 110 variable parameters were refined toR=0.042,R w=0.031 (1545 X-ray reflections withF 0 〉3σ(F 0) and sinϑ/λ⩽70°). The crystal structure is characterized by a three-dimensional corner-connection of the FeO6 octahedra with the arsenate tetrahedra and the protonated arsenate groups. Each two PbO7 polyhedra are edge-connected to Pb2O12 dimers which are located within interstitial holes.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00807393
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  • 61
    Digitale Medien
    Digitale Medien
    Crystal structure of Ag2TeS3 and Na(Na1−x Ag x )TeS3 (x≈0.5) and the geometry of Te(IV)S3 polyhedra (1997)
    Springer
    Monatshefte für Chemie 128 (1997), S. 157-163 
    Details
    ISSN: 1434-4475
    Schlagwort(e): Ag2TeS3 ; Na(Na1−x Ag x )TeS3 (x≈0.5) ; Hydrothermal syntheses ; Crystal structure ; Crystal chemistry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Es wird über die mittels Röntgenbeugungsexperimenten an Einkristallen bei 300 K bestimmten Strukturen von Ag2TeS3 (monoklin Cc-C s 4 ;a=6.783(1),b=11.567(2),c=7.693(1) Å; β=114.44(1)°;Z=4;R=0.044) und Na(Na1−x Ag x )TeS3 (x≈0.5; monoklin, P21/c-C 2h 5 ;a=5.761(9),b=12.171(8),c=8.342(4)Å; β=92.26(6)°;Z=4;R=0.030) berichtet. In beiden Verbindungen ist die Atomanordnung durch isolierte trigonal-pyramidale TeS3-Polyeder, unregelmäßig koordinierte Ag- und Na-Atome, AgS4- und (Na, Ag)S4-Polyeder bildend, sowie leicht verzerrte NaS6-Oktaeder charakterisiert. Kristalle der beiden Verbindungen wurden unter moderaten Hydrothermalbedingungen aus einem equimolaren Gemenge der Elemente und konzentrierter wäßriger Ammoniaklösung bzw. 5N NaOH-Lösung gezüchtet.
    Notizen: Summary Structural data determined by single crystal X-ray experiments (T=300 K) are reported for Ag2TeS3 (monoclinic, Cc-C s 4 ;a=6.783(1),b=11.567(2),c=7.693(1) Å; β=114.44(1)°;Z=4;R=0.044) and for Na(Na1−x Ag x )TeS3 x≈0.5; monoclinic, P21/c-C 2h 5 ;a=5.761(9),b=12.171(8),c=8.342(4) Å; β=92.26(6)°;Z=4;R=0.030). In both compounds the atomic arrangements are characterized by isolated trigonal pyramidal TeS3 polyhedra, irregularly coordinated Ag and Na atoms forming AgS4 and (Na, Ag)S4 polyhedra, and slightly distorted NaS6 octahedra. Crystals of both compounds were synthesized under moderate hydrothermal conditions from an equimolar mixture of the elements in concentrated aqueous ammonia and 5N NaOH solution, respectively.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00807304
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  • 62
    Digitale Medien
    Digitale Medien
    Enantiomere und diastereomere 2-Methoxymethyl-pyrrolidin-1-dithiocarbonsäureester (1997)
    Springer
    Monatshefte für Chemie 128 (1997), S. 881-891 
    Details
    ISSN: 1434-4475
    Schlagwort(e): 2-Methoxymethylpyrrolidine ; Carbon disulfide ; Pyrrolidine-1-dithiocarboxylates ; Crystal structure ; Diastereomers ; HPLC
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary Formation of the 2-methoxymethyl-pyrrolidine-1-dithiocarboxylates2–4 and alkylation of2 and3 were studied. Enantiomeric and diastereomeric derivatives of4, the preparation of diastereomeric mixtures of4 by alkylation of3 in the presence of strong bases, and formation of6 by phase transfer alkylation of2 are described. The two enantiomers of 2-(4-bromophenyl)-2-oxo-ethyl 2-methoxymethylpyrrolidine-1-dithiocarboxylate2 have been characterized by X-ray analysis.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00807097
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  • 63
    Digitale Medien
    Digitale Medien
    Einkristallstrukturanalyse vonBis(trimethylsilyl)peroxid (1996)
    Springer
    Monatshefte für Chemie 127 (1996), S. 1221-1227 
    Details
    ISSN: 1434-4475
    Schlagwort(e): Crystal structure ; Silylperoxide ; Crystal growth
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Summary Bis(trimethylsilyl)peroxide has been prepared from trimethylchlorsilane, hydrogen peroxide, and 1,4-diazobicyclo[2.2.2]octane. Crystal growth was achievedin situ on a diffractometer and characterized by crystal structure analysis (T=193(2) K, 2522 reflections, P21/c;a=606.7(1) pm,b=1098.5(1) pm,c=858.2(1) pm, β=101.88(2)°,Z=2,R=0.045). The molecule's conformation in the crystalline solid is determined by C-H...O-bridges.
    Notizen: Zusammenfassung Bis(trimethylsilyl)peroxid wurde aus Trimethylchlorsilan, Wasserstoffperoxid und 1,4-Diazobicyclo[2.2.2]octan dargestellt. Ein Einkristall wurdein situ auf einem Vierkreisdiffraktometer gezüchtet und mittels Einkristallstrukturanalyse charakterisiert (T=193(2) K, 2522 Reflexe, P21/c;a=606.7(1) pm,b=1098.5(1) pm,c=858.2(1) pm, β=101.88(2)°,Z=2,R=0.045). Die Konformation des Moleküls im Kristall ist durch C-H...O-Brücken bestimmt.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00807788
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  • 64
    Digitale Medien
    Digitale Medien
    Tetrakis(2-fluorophenylamino)silan und sein erstes Kondensationsprodukt N-(2-fluorophenyl)-Si, Si, Si, Si′, Si′, Si′-hexakis(2-fluorophenylamino)-disilazan. Synthesen und Kristallstrukturen (1996)
    Springer
    Monatshefte für Chemie 127 (1996), S. 117-126 
    Details
    ISSN: 1434-4475
    Schlagwort(e): Condensation ; Crystal structure ; Disilazane ; Silanetetramine
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Summary The synthesis and crystal structure determination of silanetetramine N,N′,N″,N‴2-fluorophenyl(C2/c;a=16.771(7) Å,b=16.827(5) Å,c=16.753(6) Å, ß=111.00(2)°, z=8) are reported. In a search for suitable condensation pathways to silicon/nitrogen based porous solids, N-(2-fluorophenyl)-Si,Si,Si,Si′,Si′,Si′-hexakis(2-fluorophenylamino)disilazane (2) has been obtained from the ammonium carbamate catalyzed condensation of the silanetetramine in teflon lined autoclaves. The X-ray crystal structure determination ( $$P\bar 1$$ ;a=9.331(1) Å,b=13.698(5) Å,c=16.164(4) Å, α=90.34(2)°, ß=103.03(2)°, γ=103.04(3)°, Z=2) shows the disilazane to be a dimer formed by linear condensation from the monomeric silazane.
    Notizen: Zusammenfassung Tetrakis(2-fluorophenylamino)silan (1) wurde als Precursor zur Darstellung poröser, nitridischer Festkörper synthetisiert und mit Hilfe der Einkristallröntgenstrukturanalyse charakterisiert (C2/c;a=16.771(7) Å,b=16.827(5) Å,c=16.753(6) Å, ß=111.00(2)°,z=8). Beim Erhitzen mit Ammoniumcarbamat als Katalysator wurde N-(2-fluorophenyl)-Si, Si, Si, Si′, Si′, Si′, -hexakis(2-fluorophenylamino)disilazan (2) als erstes Kondensationsprodukt isoliert ( $$P\bar 1$$ ;a=9.331(1) Å,b=13.698(5) Å,c=16.164(4) Å, α=90.34(2)°, ß=103.03(2)′, γ=103.04(3)°, Z=2).
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00807392
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  • 65
    Digitale Medien
    Digitale Medien
    Untersuchungen des Hydroxylammonium-Fluorogallats (1996)
    Springer
    Monatshefte für Chemie 127 (1996), S. 581-586 
    Details
    ISSN: 1434-4475
    Schlagwort(e): (NH3OH)3GaF6 ; Hydroxylammonium compounds ; Fluorogallates ; Crystal structure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary Crystals of (NH3OH)3GaF6 have been isolated from aqueous solution. The compound crystallizes triclinic, with cell parametersa=6.539(5) Å,b=6.924(5) Å,c=9.403(1) Å, α=87.01(9)°, β=83.98(8)°, γ=70.28(8)°. The thermal decomposition was studied by TG and DSC analysis.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00817249
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  • 66
    Digitale Medien
    Digitale Medien
    Reaction of titanocene dihalides with Na2H2 EDTA. Crystal structure of [Ti(EDTA)(H2O)] (1997)
    Springer
    Monatshefte für Chemie 128 (1997), S. 1201-1206 
    Details
    ISSN: 1434-4475
    Schlagwort(e): Titanium ; EDTA ; Crystal structure ; Sevenfold coordination
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Titanocenkomplexe ([Ti(η5-C5H4 R)2 X 2];R=H, SiMe3;X=Cl, Br) reagieren in wäßrigem Methanol mit Na2H2 EDTA unter Verdrängung der Halogen- und Cyclopentadienylliganden zum selben Produkt ([Ti(EDTA)(H2O)]). Die Struktur von ([Ti(EDTA)(H2O)]) wurde röntgenographisch bestimmt. Kristalldaten: monoklin,a=13.923(6),b=7.048(3),c=13.252(5) Å, β=90.81(1)°, RaumgruppeP21/c,Z=4. In diesem Komplex ist das Titanatom mit einem sechszähnigenEDTA-Liganden und einem Wassermolekül, das eine zusätzliche Koordinationsstelle besetzt, siebenfach koordiniert.
    Notizen: Summary Titanocene complexes ([Ti(η5-C5H4 R)2 X 2];R = H, SiMe3;X=Cl, Br) react with Na2H2 EDTA in aqueous methanol to give an identical product ([Ti(EDTA)(H2O)] by cleavage of the halogen and cyclopentadienyl ligands. The structure of [Ti(EDTA)(H2O)] has been determined by X-ray diffraction; crystal data: monoclinica=13.923(6),b=7.048(3),c=13.252(5) Å, β=90.81(1)°, space groupP21/c,Z=4. In this complex, Ti has a sevenfold coordination with a hexadentateEDTA 4− ligand and a water molecule occupying an additional coordination site.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00807251
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  • 67
    Digitale Medien
    Digitale Medien
    Untersuchungen der Hydroxylammonium-Fluorozirconate(IV) (1995)
    Springer
    Monatshefte für Chemie 126 (1995), S. 1279-1289 
    Details
    ISSN: 1434-4475
    Schlagwort(e): (NH3OH)2ZrF6 ; (NH3OH)3ZrF7 ; Hydroxylammonium compounds ; Fluorozirconates ; Crystal structure ; IR spectroscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary Hydroxylammonium fluorozirconates have been investigated. Two new microcristalline phases have been isolated from aqueous solutions: (NH3OH)2ZrF6 (1) and (NH3OH)3ZrF7 (2). The crystals were prepared by slow evaporation of the solution of NH2OH, Zr, and HF. Different compositions of the crystals were achieved by varying the molar ratios of the components. They were characterized by thermal analysis, vibrational spectroscopy, and structure (single crystal x-ray methods). (NH3OH)2ZrF6 (1) crystallizes triclinic, P $$\overline 1 $$ (No.: 2),a=7.400(2),b=7.609(2),c=7.887(2) Å, α=57.29(3)°, β=62.16(3)°, γ=67.83(2)°. (NH3OH)3ZrF7 (2) crystallizes triclinic, P $$\overline 1 $$ (No.: 2),a=7.128(1),b=7.989(1),c=8.888(1) Å, α=109.72(1)°, β=91.01(1)°, γ=104.27(1)°.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00807057
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  • 68
    Digitale Medien
    Digitale Medien
    The crystal structures ofbis-{(2-benzotrifluoride)-[(2-oxo-3H-naphth-3-ylidene)-methyl]-aminato} Copper(II) andbis-{(3-benzotrifluoride)-[(2-oxo-3H-naphth-3-ylidene)-methyl]-aminato} Copper(II) (1995)
    Springer
    Monatshefte für Chemie 126 (1995), S. 129-136 
    Details
    ISSN: 1434-4475
    Schlagwort(e): Hydroxy-naphthaleńicSchiff bases ; Schiff base Copper(II) complexes ; Crystal structure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung DieSchiffschen Basen 3-[(2-Benzotrifluorid)-2-hydroxy-3H-naphth-3-yliden)-methyl]-aldamin (1) und 3-[(3-Benzotrifluorid)-2-hydroxy-3H-naphth-3-yliden)-methyl]-aldamin (2) sowie ihre entsprechenden Cu(II)-Komplexe (I,II) wurden synthetisiert und ihre Struktur im Kristall bestimmt. VerbindungI kristallisiert triklin (a=15.561(3),b=16.211(4),c=8.007(2) Å, α=96.29(2), β=101.42(2), γ=97.10(2)°, Raumgruppe $$P_{\bar 1}$$ ,Z=2); VerbindungII kristallisiert monoklin (a=5.064(2),b=19.172(4),c=15.111(3) Å, β=95.05(2)°, Raumgruppe P21/c,Z=2). Aus der Röntgenstrukturanalyse ergibt sich eine quadratisch planare Geometrie der Komplexe.
    Notizen: Summary TheSchiff base ligands 3-[(2-benzotrifluoride)-2-hydroxy-3H-naphth-3-ylidene)-methyl] aldamine (1) and 3-[(3-benzotrifluoride)-2-hydroxy-3H-naphth-3-ylidene)-methyl] aldamine (2) and their corresponding Cu(II) complexes (I, II) were synthesized. The crystal structures ofbis-{(2-benzotrifluoride)-[(2-oxo-3H-naphth-3-ylidene)]-methyl]-aminato} Copper(II) (I) andbis-{(3-benzotrifluoride)-[(2-oxo-3H-naphth-3-ylidene)-methyl]-aminato} Copper(II) (II) were determined. CompoundI crystallizes in the triclinic crystal system (a=12.561(3),b=16.211(4),c=8.007(2) Å, α=96.29(2), β=101.42(2), γ=97.10(2)°, space group $$P_{\bar 1}$$ ,Z=2); compoundII crystallizes in the monoclinic crystal system (a=5.064(2),b=19.172(4),c=15.111(3) Å, β=95.05(2)°, space group P21/c,Z=2). The X-ray diffraction study shows that the geometry around the metal atom is square planar for both copper complexes.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00812241
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  • 69
    Digitale Medien
    Digitale Medien
    Three-Dimensional Analysis of CD6 Site-Directed Mutagenesis and Monoclonal Antibody Binding Studies Using the X-ray Structure of Mac-2 Binding Protein and a Molecular Model of the CD6 Ligand Binding Domain (1999)
    Springer
    Journal of molecular modeling 5 (1999), S. 263-270 
    Details
    ISSN: 0948-5023
    Schlagwort(e): Binding site ; Critical residues ; Crystal structure ; Model building ; Monoclonal antibodies ; Mutagenesis ; Receptor-ligand interactions
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Abstract The extracellular region of CD6 consists of three scavenger receptor cysteine-rich (SRCR) domains and binds activated leukocyte cell adhesion molecule (ALCAM), a member of the immunoglobulin superfamily (IgSF). Residues important for the CD6-ALCAM interaction have previously been identified by mutagenesis. A total of 22 CD6 residues were classified according to their importance for anti-CD6 monoclonal antibody (mAb) and/or ALCAM binding. The three-dimensional structure of the SRCR domain of Mac-2 binding protein has recently been determined, providing a structural prototype for the SRCR protein superfamily. This has made a thorough three-dimensional analysis of CD6 mutagenesis and mAb binding experiments possible. Mutation of buried residues compromised both mAb and ALCAM binding, consistent with the presence of structural perturbations. However, several residues whose mutation affected both mAb and ALCAM binding or, alternatively, only ligand binding were found to map to the surface in the same region of the domain. This suggests that the CD6 ligand binding site and epitopes of tested mAbs overlap and provides an explanation for the finding that these mAbs effectively block ALCAM binding. An approximate molecular model of CD6 was used to delineate the ALCAM binding site.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s0089490050263
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  • 70
    Digitale Medien
    Digitale Medien
    FTIR spectroscopic evidence of formation of geminal dinitrogen species during the low-temperature N2 adsorption on NaY zeolites (1999)
    Springer
    Catalysis letters 58 (1999), S. 21-26 
    Details
    ISSN: 1572-879X
    Schlagwort(e): adsorption ; adsorption isotherms ; dinitrogen ; FTIR spectroscopy ; geminal species ; NaY ; nitrogen ; zeolites
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Abstract Adsorption of N2 on NaY zeolites at 85 K and equilibrium pressures higher than 1 kPa results in the formation of geminal dinitrogen complexes characterized by an IR band at 2333.5 cm−1 (2255.4 cm−1 after adsorption of 15N2). With decreasing equilibrium pressure the complexes tend to loose one N2 ligand, thus forming linear species characterized by an IR band at 2336.8 cm−1 (2258.7 cm−1 after adsorption of 15N2). All species disappear completely after evacuation. Co-adsorption of N2 and CO revealed that the dinitrogen complexes are formed on Na+ cations. The changes in the concentrations of the linear and geminal N2 species with the changes in the equilibrium pressure are excellently described by equations of adsorption isotherms proposed earlier for mono- and di-carbonyls.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1019040825491
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  • 71
    Digitale Medien
    Digitale Medien
    Pure and Binary Gas Adsorption Equilibria and Kinetics of Methane and Nitrogen on 4A Zeolite by Isotope Exchange Technique (1999)
    Springer
    Adsorption 5 (1999), S. 145-158 
    Details
    ISSN: 1572-8757
    Schlagwort(e): kinetics ; isotope-exchange ; nitrogen ; adsorption ; methane ; zeolite ; equilibria
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Physik , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Abstract The Isotope Exchange Technique (IET) was used to simultaneously measure pure and binary gas adsorption equilibria and kinetics (self-diffusivities) of CH4 and N2 on pelletized 4A zeolite. The experiment was carried out isothermally without disturbing the adsorbed phase. CH4 was selectively adsorbed over N2 by the zeolite because of its higher polarizability. The multi-site Langmuir model described the pure gas and binary adsorption equilibria fairly well at three different temperatures. The selectivity of adsorption of CH4 over N2 increased with increasing pressure at constant gas phase composition and temperature. This curious behavior was caused by the differences in the sizes of the adsorbates. The diffusion of CH4 and N2 into the zeolite was an activated process and the Fickian diffusion model described the uptake of both pure gases and their mixtures. The self-diffusivity of N2 was an order of magnitude larger than that for CH4. The pure gas self-diffusivities for both components were constants over a large range of surface coverages (0 〈 θ 〈 0.5). The self-diffusivities of CH4 and N2 from their binary mixtures were not affected by the presence of each other, compared to their pure gas self-diffusivities at identical surface coverages.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1008917308002
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  • 72
    Digitale Medien
    Digitale Medien
    Two kinds of adsorbed N atoms with different reactivities with H2 on a Pt0.25Rh0.75(100) surface (1998)
    Springer
    Catalysis letters 52 (1998), S. 151-155 
    Details
    ISSN: 1572-879X
    Schlagwort(e): platinum ; rhodium ; alloy ; surface composition ; nitrogen ; oxygen
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Abstract Two kinds of adsorbed N atoms exist on a Pt0.25Rh0.75(100) surface. One desorbs at 490 K and the other desorbs at 650 K. The former reacts with H2 at 400 K, but the latter does not. It is supposed that the adsorption of these two N atoms is responsible of the surface composition, ratio of Pt and Rh.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1019000326574
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  • 73
    Digitale Medien
    Digitale Medien
    Effect of soil treatment with cereal straw and method of crop establishment on field pea (Pisum sativum L.) N2 fixation (1997)
    Springer
    Biology and fertility of soils 24 (1997), S. 87-95 
    Details
    ISSN: 1432-0789
    Schlagwort(e): Crop rotation ; Field pea ; Mineral N ; Nitrogen fixation ; immobilisation ; Pisum sativum
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Geologie und Paläontologie , Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract The effects of soil incorporation with cereal straw (nil, 2.5, 5 and 10 t straw ha−1) and direct drilling on the proportion and amount of pea N derived from biological N fixation were investigated in three field experiments. Fixed N was determined by15N dilution using barley as a reference plant. The three sites were on acidic, red clay-loams in the cropping zone of southeastern Australia. Seasonal plant available soil N, as determined by the N accumulated in barley, was 31, 56 and 158 kg N ha−1, for the three sites. Incorporated straw reduced soil nitrate at sowing by 10–50 kg N ha−1 (0–30 cm), and 5 or 10 t straw ha−1 reduced barley uptake of N by 10–38 kg N ha−1. However, reducing plant available soil N was generally ineffective for increasing the N fixed by pea. Fixed N increased only at the site with the least plant-available N, and only one-third of the increase could be attributed to lower soil N uptake by pea. There was no evidence that direct drilling pea increased fixed N by decreasing crop uptake of soil N. It is proposed that a lower requirement for soil N by pea as compared to barley, and availability of mineral N beneath the soil layer treated with straw, minimise the effectiveness of straw incorporation for increasing the N fixed by pea.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01420226
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  • 74
    Digitale Medien
    Digitale Medien
    Effect of soil treatment with cereal straw and method of crop establishment on field pea (Pisum sativum L.) N2 fixation (1996)
    Springer
    Biology and fertility of soils 24 (1996), S. 87-95 
    Details
    ISSN: 1432-0789
    Schlagwort(e): Key words Crop rotation ; Field pea ; Mineral N ; Nitrogen fixation ; immobilisation ; Pisum sativum
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Geologie und Paläontologie , Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract The effects of soil incorporation with cereal straw (nil, 2.5, 5 and 10 t straw ha–1) and direct drilling on the proportion and amount of pea N derived from biological N fixation were investigated in three field experiments. Fixed N was determined by 15N dilution using barley as a reference plant. The three sites were on acidic, red clay-loams in the cropping zone of southeastern Australia. Seasonal plant available soil N, as determined by the N accumulated in barley, was 31, 56 and 158 kg N ha–1, for the three sites. Incorporated straw reduced soil nitrate at sowing by 10–50 kg N ha–1 (0–30 cm), and 5 or 10 t straw ha–1 reduced barley uptake of N by 10–38 kg N ha–1. However, reducing plant available soil N was generally ineffective for increasing the N fixed by pea. Fixed N increased only at the site with the least plant-available N, and only one-third of the increase could be attributed to lower soil N uptake by pea. There was no evidence that direct drilling pea increased fixed N by decreasing crop uptake of soil N. It is proposed that a lower requirement for soil N by pea as compared to barley, and availability of mineral N beneath the soil layer treated with straw, minimise the effectiveness of straw incorporation for increasing the N fixed by pea.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01420226
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  • 75
    Digitale Medien
    Digitale Medien
    Influence of phosphorus or phosphorus-potassium fertilization on biomass and dinitrogen fixation of the stem-nodulating green-manure legume Sesbania rostrata in different marginally productive wetland rice soils (1995)
    Springer
    Biology and fertility of soils 20 (1995), S. 107-112 
    Details
    ISSN: 1432-0789
    Schlagwort(e): Wetland rice soils ; Nitrogen fixation ; Sesbania rostrata ; PK fertilization ; Soil Mn ; Acetylene reduction assay ; ARA ; Green manure ; N dilution method
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Geologie und Paläontologie , Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract The performance of Sesbania rostrata varies widely from site to site. This makes it difficult to predict the N yield and biomass of this plant in marginally productive soils, and to arouse the interest of farmers in green manure technology. Three consecutive pot experiments were conducted in a greenhouse at the International Rice Research Institute (IRRI) to evaluate growth, nodulation, N2 fixation (C2H2 reduction assay and 15N dilution method), and N yield of 6-week-old S. rostrata on 13 physicochemically different wetland rice soils of the Philippines and on three artificial substrates. The performance of S. rostrata on the unfertilized controls was compared with two fertilizer treatments containing either P (100 mg P kg-1 dry soil) or P+K (100 mg P kg-1 and 200 mg K kg-1 dry soil). In the control soils and substrates, the N yield of S. rostrata varied between 20 and 470 mg N per pot, with the N rate from N2 fixation ranging between 0 and 95%. In three of the nutritionally poor soils even Mn toxicity symptoms apparently occurred with S. rostrata. P application alleviated these symptoms and increased the overall N yield considerably, mainly through increased biological N2 fixation. An additional increase in N yield was obtained by the PK treatment. Multiple regression analysis between soil characteristics and the N yield of S. rostrata showed that the original level of P (Olsen-extracted) and Mn in the soil accounted for 73% of the variance in biomass production by S. rostrata among the unfertilized soils and substrates.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00336588
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  • 76
    Digitale Medien
    Digitale Medien
    The role of potassium fertilizer in nodulation and nitrogen fixation of faba bean (Vicia faba L.) plants under drought stress (1995)
    Springer
    Biology and fertility of soils 20 (1995), S. 147-150 
    Details
    ISSN: 1432-0789
    Schlagwort(e): Faba bean ; Water stress ; Nodulation ; Nitrogen fixation ; Leghaemoglobin ; Invertase ; Protease ; K fertilizer
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Geologie und Paläontologie , Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract Three-week-old nodulated faba bean plants were subjected to different levels of drought stress (onehalf, one-quarter, or one-eighth field capacity) for 5 weeks. Half the stressed plants were treated with KCl at 10 mg kg-1 soil or 150 mg kg-1 soil at the beginning of the drought stress. Nodulation and nitrogenase activity were significantly decreased by increasing drought stress. Leghaemoglobin and protein contents of nodule cytosol were also severely inhibited by drought sttess. This decline was attributed to the induction of protease activity. However, carbohydrate contents of the nodule cytosol increased significantly. This accumulation was attributed to a sharp decline in invertase activity and low use of sugar by the bacteroids We conclude that harmful effects of water deficits can be alleviated by increasing K+ supplementation.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00336594
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  • 77
    Digitale Medien
    Digitale Medien
    Dynamics of nodulation, nitrogen fixation, nitrogen use and biomass yield over time in pot-grown Leucaena leucocephala (Lam.) de Wit (1995)
    Springer
    Biology and fertility of soils 20 (1995), S. 163-168 
    Details
    ISSN: 1432-0789
    Schlagwort(e): Leucaena ; Nodulation ; Nitrogen fixation ; Nitrogen use ; 15N ; Time course
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Geologie und Paläontologie , Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract The dynamics of nodulation, N2-fixation and N use in Leucaena leucocephala cv. K28 over time was investigated in a screenhouse at 4, 8, 12 and 16 months after planting (MAP) using the 15N-labelling method. Leucaena had a consistently increasing pattern of nodulation, dry biomass and nitrogen yield. A sharp rise in nodulation was observed between 12 and 16 MAP, whereas for biomass, N accumulation and N2-fixation, and N2-fixation, an upward surge occurred between 4 and 12 months. Nodulation, N accumulation, N2-fixation and biomass yield all peaked at 16 MAP. Along with the steady increase in N2-fixation throughout the 16-month growth period, the % N derived from the atmosphere rose from 17.9% to 61.5%, 70.1% and 74%, equivalent to 191, 1623, 2395 and 3385 mg N2 fixed plant-1 at 4, 8, 12 and 16 MAP, respectively. Nitrogen assimilation from soil and fertilizer decreased inversely to the increase in symbiotic nitrogen fixation with time.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00336553
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  • 78
    Digitale Medien
    Digitale Medien
    Comparison of symbiotic effectiveness of Rhizobium sp. with positive hydrogen-uptake activity compared with negative mutants in relation to nitrogen fixation in mungbean (Vigna radiata L.) (1995)
    Springer
    Biology and fertility of soils 20 (1995), S. 270-274 
    Details
    ISSN: 1432-0789
    Schlagwort(e): Mungbean ; Vigna radiata ; Nitrogen fixation ; Hydrogen uptake ; Mutation ; Nitrosoguanidine
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Geologie und Paläontologie , Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract H2 uptake activity was well distributed in Rhizobium sp. strains isolated from nodules of mung-bean (Vigna radiata L.). Two effective strains, RMP1 und RMP2, exhibiting significantly higher H2 uptake activity were subjected to mutagenesis with nitrosoguanidine. The respective mutation frequencies were 0.18 and 0.19%. Three Hup- mutants each of RMP1 und RMP2 were compared with the wild-type parent strains under pot culture experiments to evaluate the significance of the H2 uptake system in biological N2 fixation. Nodulation capabilities, plant growth characteristics, and the chlorophyll content of the leaves were significantly reduced in the plants treated with Hup- mutants. Nitrogenase activity in Hup- nodules was reduced by 8–41%. Similarly, N accumulation was also reduced singificantly.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00336089
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  • 79
    Digitale Medien
    Digitale Medien
    Occurrence of the endophytic diazotrophs Herbaspirillum spp. in roots, stems, and leaves, predominantly of Gramineae (1996)
    Springer
    Biology and fertility of soils 21 (1996), S. 197-200 
    Details
    ISSN: 1432-0789
    Schlagwort(e): Herbaspirillum ; Endophytes of Gramineae ; Diazotrophs ; Survival in soil ; Nitrogen fixation ; sugarcane
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Geologie und Paläontologie , Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract Since the first description of Herbaspirillum seropedicae in 1986, few data have been published on this diazotroph, possibly due to difficulties in isolating it from soil. In the present study we found that this bacterium seems to be an obligate endophyte which has been isolated from roots, stems, and leaves of a large number of samples of more than 10 different species of the Gramineae family, but only exceptionally from other plants. H. rubrisubalbicans, previously misnamed as “Pseudomonas” rubrisubalbicans, and known as a mild pathogen of sugarcane causing mottled stripe disease, confirms the endophytie habitat of this genus. This species occurs in roots, stems, and leaves of sugarcane and seems to be restricted to this crop. Inoculation of strains from both species into soil in high numbers resulted in a rapid decline in their numbers. In only 30 days the population of Herbaspirillum spp. in soil decreased below detection limits (〈100 cells g-1). When sorghum was planted in this soil, the bacteria reappeared and multiplied within the plant tissues.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00335935
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  • 80
    Digitale Medien
    Digitale Medien
    Short- and long-term effects of ammonium on photodependent nitrogen fixation in wetland rice fields of Spain (1997)
    Springer
    Biology and fertility of soils 24 (1997), S. 353-357 
    Details
    ISSN: 1432-0789
    Schlagwort(e): Key words Acetylene reduction assay ; Anabaena sp. ; Ammonium ; Cyanobacteria ; Nitrogen fixation ; Wetland rice fields ; Nitrogenase activity
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Geologie und Paläontologie , Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract Short- and long-term experiments were conducted in the rice fields of Valencia, Spain, to determine the ecological significance of ammonium on nitrogen fixation. A significant inhibition of nitrogenase activity by ammonium, at concentrations higher than 0.5mM, was observed after 8h of incubation in short-term experiments done with a bloom of the N2-fixing cyanobacterium Anabaena sp. In a second set of short-term experiments for in situ assays of nitrogenase activity in the field, a significant correlation between nitrogenase activity and the number of N2-fixing cyanobacteria in soil was found. No significant inhibition of nitrogenase activity by ammonium at concentrations up to 2mM was observed in these assays after 24h of incubation. This lack of inhibition was probably due to the rapid decrease in ammonium content in the flood water. Only 5% of the ammonium initially added remained in the water 24h later. In the long-term experiments, nitrogenase activity was assayed in plots fertilized with 0, 70 and 140kgNha–1, over the cultivation cycle, for 5 years. A partial inhibition of nitrogenase activity by deep-placed N fertilizers was observed. Differences were only significant in 2 years. Mean results from 5 years only showed significant differences between plots fertilized with 0 and 140kgNha–1. The partial inhibition of nitrogenase activity by ammonium increased over the cultivation cycle. Inhibition was only significant in September, at the end of the cultivation cycle.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s003740050257
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  • 81
    Digitale Medien
    Digitale Medien
    Phenotypic grouping of Brazilian Bradyrhizobium strains which nodulate soybean (1997)
    Springer
    Biology and fertility of soils 25 (1997), S. 407-415 
    Details
    ISSN: 1432-0789
    Schlagwort(e): Key wordsBradyrhizobium japonicum ; Bradyrhizobium elkanii ; Genetic variability ; Glycine max ; Nitrogen fixation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Geologie und Paläontologie , Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract Several years of research have shown that there is a high genetic and physiological variability among Bradyrhizobium japonicum strains, culminating in a subdivision into two bacterial genotypes, and the description of the new species B. elkanii. In Brazil, large-scale soybean inoculation started in 1960 and today 15 million doses of inoculants are sold per year for an estimated area of 12 million ha. Efforts have been made to find strains able to fix high amounts of N2 under Brazilian soil conditions, but few laboratories cover basic studies on N2 fixation, such as strain classification into the two Bradyrhizobium species. In this study several characteristics of 40 soybean Bradyrhizobium strains, including 4 reference strains of B. japonicum (genotype I) species, 3 of B. elkanii (genotype II) and 1 of a mixed genotype were evaluated. The parameters analysed in vitro were: colony morphology, serological grouping, intrinsic resistance to antibiotics, synthesis of indole acetic acid, expression of hydrogenase activity and growth in a medium enriched with asparagine. In vivo, analyses performed included the nodulation of Rj 4 soybean cultivar Hill and the detection of symptoms caused by rhizobitoxine. These evaluations allowed a phenotypic grouping which positioned most of the strains utilized in Brazilian inoculants and studies, as well as some new strains isolated from the Cerrado region, within the species B. elkanii. However, environmental stresses and adaptation of Bradyrhizobium strains to the soil caused a large physiological and genetic variability in some isolates from the Cerrado soils in relation to the putative parental strain introduced 15 years ago, placing these isolates in an intermediate position between the two Bradyrhizobium species.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s003740050333
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  • 82
    Digitale Medien
    Digitale Medien
    Nodulation pattern and acetylene reduction (nitrogen fixation) activity of some highland and lowland Acacia species of Ethiopia (1998)
    Springer
    Biology and fertility of soils 27 (1998), S. 60-64 
    Details
    ISSN: 1432-0789
    Schlagwort(e): Key words Acacia spp. ; Bradyrhizobium ; Rhizobium ; Nitrogen fixation ; Nitrogen accumulation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Geologie und Paläontologie , Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract  Endosymbionts from the Ethiopian highland acacia species Acacia abyssinica, A. negrii and A. etbaica, and the lowland species A. nilotica, A. prasinata, A.senegal, A. seyal, A. tortilis and Faidherbia (Acacia) albida were isolated and characterized. Seven tree species were found to be nodulated by species of both Rhizobium and Bradyrhizobium. F. (Acacia) albida and A. senegal were nodulated by only Bradyrhizobium or Rhizobium, respectively. In A. abyssinica, both genera were isolated from the same nodule, whereas in A. nilotica and A. tortilis, both strains were isolated from different nodules of the same plant. The nitrogen fixation (acetylene reduction) activities varied considerably and showed no correlation with the nitrogen content of the plant. Highland species were as effective as lowland plants, thus demonstrating good potential for soil reclamation. The endosymbionts isolated proved rather promiscuous, efficiently nodulating other Acacia spp. and some tropical grain legumes, but did not nodulate temperate legumes.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s003740050400
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  • 83
    Digitale Medien
    Digitale Medien
    Nitrogen fixation capacity and nodule occupancy by Bradyrhizobium japonicum and B. elkanii strains (1998)
    Springer
    Biology and fertility of soils 27 (1998), S. 393-399 
    Details
    ISSN: 1432-0789
    Schlagwort(e): Key words Bradyrhizobium japonicum ; Bradyrhizobium elkanii ; Competitiveness ; Nitrogen fixation ; Soybean
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Geologie und Paläontologie , Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract  In a previous study soybean Bradyrhizobium strains, used in Brazilian studies and inoculants over the last 30 years, and strains adapted to the Brazilian Cerrados, a region frequently submitted to environmental and nutritional stresses, were analyzed for 32 morphological and physiological parameters in vivo and in vitro. A cluster analysis allowed the subdivision of these strains into species Bradyrhizobium japonicum, Bradyrhizobium elkanii and a mixed genotype. In this study, the bacteria were analyzed for nodulation, N2 fixation capacity, nodule occupancy and the ability to increase yield. The goal was to find a relationship between the strain groups and the symbiotic performance. Two strains of Brazilian B. japonicum showed higher rates of N2 fixation and nodule efficiency (mg of N mg–1 of nodules) under axenic conditions. These strains also showed greater yield increases in field experiments when compared to B. elkanii strains. However, no differences were detected between B. japonicum and B. elkanii strains when comparing nodule occupancy capacity. The adapted strains belonging to the serogroup B. elkanii SEMIA 566, most clustered in a mixed genotype, were more competitive than the parental strain, and some showed a higher capacity of N2 fixation. Some of the adapted strains, such as S-370 and S-372, have shown similar N2 fixation rates and nodulation competitiveness to two Brazilian strains of B. japonicum. This similarity demonstrates the possibility of enhancing N2 fixing ability, after local adaptation, even within B. elkanii species. Differences in the DNA profiles were also detected between the parental SEMIA 566 and the adapted strains by analyses with the ERIC and REP-PCR techniques. Consequently, genetic, morphological and physiological changes can be a result of adaptation of rhizobia to the soil. This variability can be used to select strains capable of increasing the contribution of N2 fixation to soybean nutrition.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s003740050449
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  • 84
    Digitale Medien
    Digitale Medien
    Renodulation and characterization of Rhizobium isolates from cicer milkvetch (Astragalus cicer L.) (1997)
    Springer
    Biology and fertility of soils 25 (1997), S. 169-174 
    Details
    ISSN: 1432-0789
    Schlagwort(e): Key wordsAstragalus cicer ; Nodulation ; DNA ; Milkvetch ; Nitrogen fixation ; Forage legume ; Rhizobium spp.
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Geologie und Paläontologie , Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract In 1993 and 1994, 12 bacterial isolates were isolated from root nodules of cicer milkvetch (Astragalus cicer). In the tests for nodulation of A. cicer by these bacterial isolates, five were found to form hypertrophic structures, while only two formed true nodules. These true nodules were formed in a sterilized soil system. This system might be able to act as a DNA donor to provide residual DNA to other microbes in the soil. The rhizobial isolates were thought to have lost genetic material crucial to nodulation during the isolation process. This hypothesis was supported by an experiment in which isolate B2 was able to nodulate A. cicer in vermiculite culture after being mixed with heat-killed rhizobia, Rhizobium leguminosarum bv. trifolii and R. loti. The nodulation would not occur in vermiculite culture system without the heat-killed rhizobia. Based on the biochemical data, the B2 and 9462L, which formed true nodules with A. cicer, were closely related. The rhizobia type cultures that nodulate A. cicer include Bradyrhizobium japonicum, Rhizobium leguminosarum bv. trifolii, R. leguminosarum bv. viceae, and R. loti. All of these rhizobia were from different cross-inoculation groups. The B2 and 9462L isolates could only nodulate Medicago sativa, Phaseolus vulgaris, and Melilotus officinalis, but not these species within the genus from which they were isolated: Astragalus. The traditional cross-inoculation group concept obviously does not fit well in the classification of rhizobia associated with Astragalus. The rhizobia isolated from A. cicer can be quite different, and the rhizobia able to renodulate A. cicer also quite diverse.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s003740050299
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  • 85
    Digitale Medien
    Digitale Medien
    Dual inoculation with strains of Bradyrhizobium japonicum and Azospirillum brasilense to improve growth and biological nitrogen fixation of soybean (Glycine max L.) (1997)
    Springer
    Biology and fertility of soils 24 (1997), S. 317-322 
    Details
    ISSN: 1432-0789
    Schlagwort(e): Key words Soybean ; Isotope dilution ; Nitrogen fixation ; Bradyrhizobium japonicum ; Soil sterilization ; 15N ; Azospirillum brasilense ; Bacterial inoculation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Geologie und Paläontologie , Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract The effects of inoculation with Bradyrhizobium japonicum and Azospirillum brasilense strains on the growth of soybean were evaluated with regard to the estimation of N2 fixation using the 15N isotope dilution technique. Inoculation, in general, increased the dry mass of soybean as well as nitrogen content. Dual inoculation with a mixture of B. japonicum and A. brasilense strains was superior over single inoculation with B. japonicum. Nitrogen fixed (Ndfa) varied according to inoculant and soil conditions. Percentages of nitrogen derived from air (% Ndfa) using a non-nodulating isoline were 72% and 76% for B. japonicum and B. japonicum plus A. brasilense, respectively, in non-sterile soil. A similar but higher trend was recorded in sterilized soil, in which the percentages of N2 fixed were 81% and 86% for single and dual inoculation, respectively. The correlation coefficient between N2 fixed and N uptake (r=0.94) and dry mass (r=0.89) was significant. Application of special bacterial inoculants in agricultural systems of Egypt seems to be a promising technology and could be used for improving soybean growth as well as soil fertility, thus minimizing environmental pollution.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s003740050250
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  • 86
    Digitale Medien
    Digitale Medien
    Influence of long-term conservation tillage on soil and rhizosphere microorganisms (1999)
    Springer
    Biology and fertility of soils 29 (1999), S. 81-86 
    Details
    ISSN: 1432-0789
    Schlagwort(e): Key words Soil tillage ; Rhizosphere microorganisms ; Cereals ; Nitrogen fixation ; Gaeumanomyces graminis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Geologie und Paläontologie , Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract  In long-term field experiments on sandy loam and loamy sand soils, the influence of conservation and conventional tillage on soil and rhizosphere microorganisms was studied. Conservation tillage stimulated rhizosphere bacteria on winter wheat, winter barley, winter rye and maize in different soil layers. Particularly the populations of Agrobacterium spp. and Pseudomonas spp. were increased. On the sandy loam, N2 fixation and nodulation of pea plants were significantly increased. No influence of different soil tillage was determined on the colonization of the rhizosphere by mycorrhiza and saprophytic fungi. Stubble residues infected with Gaeumanomyces graminis were infectious for a longer time on the soil surface than after incorporation into the soil.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s003740050528
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  • 87
    Digitale Medien
    Digitale Medien
    Fate of blue-green algae in the food web of flooded rice-field ecosystems (1999)
    Springer
    Biology and fertility of soils 29 (1999), S. 141-145 
    Details
    ISSN: 1432-0789
    Schlagwort(e): Key words Blue-green algae ; Nitrogen fixation ; Rice ecosystem ; Zooplankton ; Benthos
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Geologie und Paläontologie , Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract  As part of an integrated pest management project to study the role blue-green algae (BGA) may play in the food web of rice-field ecosystems, 14C-labelled filamentous and monocellular BGA were used as food for fish, zooplankton and benthic fauna in artificial rice fields in the form of three aquaria. 14C present in the organisms was then traced by liquid scintillation to follow the manner in which the labelled BGA were consumed by different organisms. In this study the grazing rate of fish (mud carp) was compared to that of benthic organisms and zooplankton. It was found that fish consumed the BGA at the fastest rates and in the largest amounts, followed by the benthic species and zooplankton. It was also found that filamentous BGA were consumed in higher amounts than monocellular BGA. The importance of grazing in nutrient recycling is emphasized.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s003740050536
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  • 88
    Digitale Medien
    Digitale Medien
    Management-induced change in labile soil organic matter under continuous corn in eastern Canadian soils (1997)
    Springer
    Biology and fertility of soils 26 (1997), S. 88-94 
    Details
    ISSN: 1432-0789
    Schlagwort(e): Key words Microbial biomass C ; Water-soluble organic carbon ; Light fraction organic carbon ; Fertilizer ; nitrogen ; 13C nuclear magnetic resonance ; Infrared spectrophotometry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Geologie und Paläontologie , Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract Soil samples taken from four experimental sites that had been cropped to continuous corn for 3–11 years in Ontario and Quebec were analyzed to evaluate changes in quantity and quality of labile soil organic carbon under different nitrogen (N) fertility and tillage treatments. Addition of fertilizer N above soil test recommendations tended to decrease amounts of water-soluble organic carbon (WSOC) and microbial biomass carbon (MBC). The quality of the WSOC was characterized by 13C nuclear magnetic resonance and infrared spectrophotometry and the results indicated that carbohydrates, long-chain aliphatics and proteins were the major components of all extracts. Similar types of C were present in all of the soils, but an influence of management was evident. The quantity of soil MBC was positively related to the quantities of WSOC, carbohydrate C, and organic C, and negatively related to quantities of long-chain aliphatic C in the soil. The quantity of WSOC was positively related to the quantities of protein C, carbohydrate C, and negatively related to the quantity of carboxylic C. The quantity of soil MBC was not only related to quantities of soil WSOC but also to the quality of soil WSOC.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s003740050348
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  • 89
    Digitale Medien
    Digitale Medien
    Diurnal and seasonal patterns of nitrogenase activity of red alder in comparison with white clover in silvopastoral agroforestry systems (1999)
    Springer
    Biology and fertility of soils 28 (1999), S. 267-270 
    Details
    ISSN: 1432-0789
    Schlagwort(e): Key words Red alder ; White clover ; Nitrogenase activity ; Acetylene reduction assay ; Nitrogen fixation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Geologie und Paläontologie , Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract  Simultaneous measurements were made to assess the diurnal and seasonal patterns of nitrogenase activity of red alder (Alnus rubra Bong.) and white clover (Trifolium repens L.) growing together in a silvopastoral agroforestry system using the acetylene reduction assay. Diurnal measurements were made in the summer and autumn at 3-h intervals whereas seasonal nitrogenase activity was assessed based on observations made at midday in July, September and January to represent the summer, autumn and winter seasons, respectively. No obvious diurnal patterns of nitrogenase activity were found in either red alder or white clover in summer and no significant variations in nitrogenase activity were observed between day and night. However, in autumn, pronounced diurnal patterns were observed in both species. Significantly higher rates of nitrogenase activity per unit dry weigh (dwt) of nodules were detected at 1500 hours in red alder, whereas, in white clover, significantly higher rates were obtained at 2100 hours. There was no significant correlation between diurnal nitrogenase activity and air temperature, photosynthetically active radiation and soil temperature at 10 cm depth in either red alder or white clover. Seasonal rates of nitrogenase activity showed significantly higher activity in summer, which subsequently decreased in autumn, to reach very low levels in the winter. The rates of nitrogenase activity of white clover were consistently higher than those of red alder both diurnally and seasonally. In the three seasons sampled, the average nitrogenase activity for white clover was 66.42 μmol C2H4 g dwt–1 h–1, which was 3.5 times higher than the 18.67 μmol C2H4 g dwt–1 h–1 obtained for red alder.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s003740050492
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  • 90
    Digitale Medien
    Digitale Medien
    Relationships between soil aggregation and mycorrhizae as influenced by soil biota and nitrogen nutrition (1999)
    Springer
    Biology and fertility of soils 28 (1999), S. 356-363 
    Details
    ISSN: 1432-0789
    Schlagwort(e): Key words Arbuscular mycorrhiza ; Collembola ; Nitrogen fertilization ; Nitrogen fixation ; Soil aggregation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Geologie und Paläontologie , Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract  The effect of the form of N nutrition on soil stability is an important consideration for the management of sustainable agricultural systems. We grew soybean [Glycine max (L.) Merr.] plants in pot cultures in unsterilized soil, and treated them by (1) inoculating them with Bradyrhizobium japonicum, fertilizing with (2) nitrate or (3) ammonia, or (4) by providing only minimum N amendment for the controls. The soils were sampled at 3-week intervals to determine changes in water-stable soil aggregates (WSA), soil pH, the development of roots, arbuscular mycorrhizal (AM) soil and root colonization, and selected functional groups of soil bacteria. The soil fauna was assayed at the end of the experiment (9 weeks). WSA was correlated positively with root and AM soil mycelium development, but negatively with total bacterial counts. Soil arthropod (Collembola) numbers were negatively correlated with AM hyphal length. Soils of nodulated and ammonia-fertilized plants had the highest levels of WSA and the lowest pH at week 9. Sparse root development in the soils of the N-deficient, control plants indicated that WSA formation was primarily influenced by AM hyphae. The ratio of bacterial counts in the water-stable versus water-unstable soil fractions increased for the first 6 weeks and then declined, while counts of anaerobic bacteria increased with increasing WSA. The numbers of soil invertebrates (nematodes) and protozoans did not correlate with bacterial counts or AM soil-hyphal lengths. Soil pH did not affect mycorrhiza development, but actinomycete counts declined with decreasing soil pH. AM fungi and roots interacted as the factors that affect soil aggregation, regardless of N nutrition.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s003740050504
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  • 91
    Digitale Medien
    Digitale Medien
    Adaptation of green manure legumes to adverse conditions in rice lowlands (1996)
    Springer
    Biology and fertility of soils 23 (1996), S. 243-248 
    Details
    ISSN: 1432-0789
    Schlagwort(e): Key words Adverse soil conditons ; Aeschynomene ; Green manure ; Lowland rice ; Nitrogen fixation ; Sesbania ; Forming system development
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Geologie und Paläontologie , Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract Poor adoption of sustainable pre-rice green manure technology by lowland farmers is frequently associated with unreliable legume performance under adverse environmental conditions such as marginal soils, short photoperiod, and unfavorable hydrology. A series of field and microplot experiments were conducted at the International Rice Research Institute (IRRI) in 1991 and 1992 to screen and evaluate 12 promising flood-tolerant legumes for adaptation (N accumulation and biological N2 fixation) to a range of environmental stresses, frequently encountered in rice lowlands. Legumes belonging to the genera Sesbania and Aeschynomene were grown for 8 weeks at 10×10 cm spacing: (1) in a fertile control soil and in four marginally productive irrigated lowland rice soils (sandy Entisol, P-deficient Inceptisol, acid Ultisol, and saline Mollisol); (2) during short- (11.7 h) and long-day (12.3 h) seasons in a favorable irrigated lowland soil; and (3) in an aerobic soil (drought-prone rain-fed lowland) and a deep-flood-prone lowland soil (1 week seedling submergence). A large variability in N accumulation was observed among legume species and across different environments, ranging from less than 1 to over 70 mg N plant–1. The nitrogen derived from the atmosphere (Ndfa) accounted on average for 82% of total N accumulation. Sesbania virgata was least affected by unfavorable soil conditions but its Ndfa was the lowest among the tested species (less than 60%). Stem nodule formation did not convey a significant advantage to legumes grown under adverse soil conditions. However, flooding reduced N2 fixation less in stem-nodulating than in solely root-nodulating species. Most species drastically reduced N accumulation under short-day conditions. Aeschynomene afraspera and S. speciosa were least affected by photoperiod. The considerable genetic variability in the germplasm screened allows the selection of potentially appropriate legumes to most conditions studied, thus increasing N accumulation in green manures.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00335951
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  • 92
    Digitale Medien
    Digitale Medien
    Soil surface disturbances in cold deserts: effects on nitrogenase activity in cyanobacterial-lichen soil crusts (1996)
    Springer
    Biology and fertility of soils 23 (1996), S. 362-367 
    Details
    ISSN: 1432-0789
    Schlagwort(e): Cryptobiotic ; Cryptogamic ; Microphytic ; Microbiotic ; Deserts ; Nitrogen fixation ; Nutrient cycling ; Lichens ; Microcoleus vaginatus ; Collema tenax ; Heterocysts ; Acetylene reduction assay ; ARA
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Geologie und Paläontologie , Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract Cyanobacterial-lichen soil crusts can be a dominant source of nitrogen for cold-desert ecosystems. Effects of surface disturbance from footprints, bike and vehicle tracks on the nitrogenase activity in these crusts was investigated. Surface disturbances reduced nitrogenase activity by 30–100%. Crusts dominated by the cyanobacterium Microcoleus vaginatus on sandy soils were the most susceptible to disruption; crusts on gypsiferous soils were the least susceptible. Crusts where the soil lichen Collema tenax was present showed less immediate effects; however, nitrogenase activity still declined over time. Levels of nitrogenase activity reduction were affected by the degree of soil disruption and whether sites were dominated by cyanobacteria with or without heterocysts. Consequently, anthropogenic surface disturbances may have serious implications for nitrogen budgets in these ecosystems.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00335908
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  • 93
    Digitale Medien
    Digitale Medien
    Soil surface disturbances in cold deserts: effects on nitrogenase activity in cyanobacterial-lichen soil crusts (1996)
    Springer
    Biology and fertility of soils 23 (1996), S. 362-367 
    Details
    ISSN: 1432-0789
    Schlagwort(e): Key words Cryptobiotic ; Cryptogamic ; Microphytic ; Microbiotic ; Deserts ; Nitrogen fixation ; Nutrient ; cycling ; Lichens ; Microcoleus vaginatus ; Collema tenax ; Heterocysts ; Acetylene reduction assay ; ARA
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Geologie und Paläontologie , Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract Cyanobacterial-lichen soil crusts can be a dominant source of nitrogen for cold-desert ecosystems. Effects of surface disturbance from footprints, bike and vehicle tracks on the nitrogenase activity in these crusts was investigated. Surface disturbances reduced nitrogenase activity by 30–100%. Crusts dominated by the cyanobacterium Microcoleus vaginatus on sandy soils were the most susceptible to disruption; crusts on gypsiferous soils were the least susceptible. Crusts where the soil lichen Collema tenax was present showed less immediate effects; however, nitrogenase activity still declined over time. Levels of nitrogenase activity reduction were affected by the degree of soil disruption and whether sites were dominated by cyanobacteria with or without heterocysts. Consequently, anthropogenic surface disturbances may have serious implications for nitrogen budgets in these ecosystems.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s003740050184
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  • 94
    Digitale Medien
    Digitale Medien
    Survival and symbiotic properties of Bradyrhizobium japonicum in the presence of thiram: isolation of fungicide resistant strains (1997)
    Springer
    Biology and fertility of soils 26 (1997), S. 141-145 
    Details
    ISSN: 1432-0789
    Schlagwort(e): Key wordsBradyrhizobium japonicum ; Nodulation ; Nitrogen fixation ; Soybean ; Thiram
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Geologie und Paläontologie , Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract The fungicide thiram, widely used as a chemical seed protectant, induces a strong inhibition of primary nodulation in the crown zone of soybean roots. The present work reports on the isolation of Bradyrhizobium japonicum strains resistant to thiram, some of which (T3B, A86 and A2) maintained their capacity for nodulation and were still efficient symbionts, but some (A1, C1 and C6) lost the ability to stimulate nodulation. Characterization tests such as growth at different pH, denitrifying ability, salt tolerance, production of siderophores and phosphate solubilization were performed on the resistant strains. Inoculants produced from these strains could be appropriate for use with thiram-treated seeds, without causing a loss of bacteria viability.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s003740050357
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  • 95
    Digitale Medien
    Digitale Medien
    Natural abundance of 15N in sweet potato, pumpkin, sorghum and castor bean: possible input of N2-derived nitrogen in sweet potato (1997)
    Springer
    Biology and fertility of soils 26 (1997), S. 152-154 
    Details
    ISSN: 1432-0789
    Schlagwort(e): Key wordsCucurbita moschata ; Ipomoea batatas ; Nitrogen fixation ; δ15N method ; Sorghum bicolor
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Geologie und Paläontologie , Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract Two combinations of plant species, sweet potato (three cultivars) and pumpkin, and sweet sorghum (three cultivars) and castor bean were grown separately in three plots of alluvial soil from June to September 1996. The shoots (leaves plus stems) of sweet potato and pumpkin, and the whole tops (leaves plus stems and grains) of sweet sorghum and castor bean were harvested twice, once in August and once in September in order to analyze their natural abundance of 15N (δ15N). The δ15N values of two of the varieties of sweet potato harvested in September were significantly lower than those of pumpkin, while δ15N values of sweet potato and pumpkin harvested in August, as well as those of sweet sorghum and castor bean harvested in August and September, did not significantly differ. The lower δ15N values observed in the September-harvested sweet potato may indicate that as much as 40% of the N intake of this species is derived from dinitrogen. This species is known to have a high ability to take up N from undefined sources.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s003740050359
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  • 96
    Digitale Medien
    Digitale Medien
    Nitrogen uptake and growth of two citrus rootstock seedlings in a sandy soil receiving different controlled-release fertilizer sources (1998)
    Springer
    Biology and fertility of soils 26 (1998), S. 169-172 
    Details
    ISSN: 1432-0789
    Schlagwort(e): Key words Urea ; Coated fertilizers ; Ammonium ; nitrogen ; Nitrate nitrogen ; Nitrogen uptake
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Geologie und Paläontologie , Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract Understanding the fate of different forms of nitrogen (N) fertilizers applied to soils is an important step in enhancing N use efficiency and minimizing N losses. The growth and N uptake of two citrus rootstocks, Swingle citrumelo (SC), and Cleopatra mandarin (CM), seedlings were evaluated in a pot experiment using a Candler fine sand (hyperthermic, uncoated, Typic Quartzipsamments) without N application or with 400 mg N kg–1 applied as urea or controlled-release fertilizers (CRF; either as Meister, Osmocote, or Poly-S). Meister and Osmocote are polyolefin resin-coated urea with longevity of N release for 270 days (at 25°C). Poly-S is a polymer and sulfur-coated urea with release duration considerably shorter than that of either Meister or Osmocote. The concentrations of 2 M KCl extractable nitrate nitrogen (NO3 –-N) and ammonium nitrogen (NH4 +-N) in the soil sampled 180 days and 300 days after planting were greater in the soil with SC than with CM rootstock seedlings. In most cases, the extractable NH4 + and NO3 – concentrations were greater for the Osmocote treatment compared to the other N sources. For the SC rootstock seedlings, dry weight was greater with Meister or Poly-S compared with either Osmocote or urea. At the end of the experiment, ranking of the various N sources, with respect to total N uptake by the seedlings, was: Meister = Osmocote 〉 Poly-S 〉 Urea 〉 no N for CM rootstock, and Meister = Poly-S = Osmocote 〉 Urea 〉 no N for SC rootstock. The study demonstrated that for a given rate of N application the total N uptake by seedlings was greater for the CRF compared to urea treatment. This suggests that various N losses were lower from the CRF source as compared to those from soluble fertilizers.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s003740050363
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  • 97
    Digitale Medien
    Digitale Medien
    Adaptation of green manure legumes to adverse conditions in rice lowlands (1996)
    Springer
    Biology and fertility of soils 23 (1996), S. 243-248 
    Details
    ISSN: 1432-0789
    Schlagwort(e): Adverse soil conditons ; Aeschynomene ; Green manure ; Lowland rice ; Nitrogen fixation ; Sesbania ; Forming system development
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Geologie und Paläontologie , Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract Poor adoption of sustainable pre-rice green manure technology by lowland farmers is frequently associated with unreliable legume performance under adverse environmental conditions such as marginal soils, short photoperiod, and unfavorable hydrology. A series of field and microplot experiments were conducted at the International Rice Research Institute (IRRI) in 1991 and 1992 to screen and evaluate 12 promising flood-tolerant legumes for adaptation (N accumulation and biological N2 fixation) to a range of environmental stresses, frequently encountered in rice lowlands. Legumes belonging to the genera Sesbania and Aeschynomene were grown for 8 weeks at 10×10 cm spacing: (1) in a fertile control soil and in four marginally productive irrigated lowland rice soils (sandy Entisol, P-deficient Inceptisol, acid Ultisol, and saline Mollisol); (2) during short- (11.7h) and long-day (12.3 h) seasons in a favorable irrigated lowland soil; and (3) in an aerobic soil (drought-prone rain-fed lowland) and a deep-flood-prone lowland soil (1 week seedling submergence). A large variability in N accumulation was obsersed among legume species and across different environments, ranging from less than 1 to over 70 mg N plant-1. The nitrogen derived from the atmosphere (Ndfa) accounted on average for 82% of total N accumulation. Sesbania virgata was least affected by unfavorable soil conditions but its Ndfa was the lowest among the tested species (less than 60%). Stem nodule formation did not convey a significant advantage to legumes grown under adverse soil conditions. However, flooding reduced N2 fixation less in stem-nodulating than in solely root-nodulating species. Most species drastically reduced N accumulation under short-day conditions. Aeschynomene afraspera and S. speciosa were least affected by photoperiod. The considerable genetic variability in the germplasm screened allows the selection of potentially appropriate legumes to most conditions studied, thus increasing N accumulation in green manures.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00335951
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  • 98
    Digitale Medien
    Digitale Medien
    Nitrogen use in maize-grain legume cropping systems in semi-arid Kenya (1995)
    Springer
    Biology and fertility of soils 20 (1995), S. 57-62 
    Details
    ISSN: 1432-0789
    Schlagwort(e): Nitrogen use ; Nitrogen fertilizer recovery ; Zea mays ; Phaseolus vulgaris ; Vigna unguiculata ; Nitrogen fixation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Geologie und Paläontologie , Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract Locally suitable cultivars of maize, beans, and cowpeas were grown in field experiments for four seasons in semi-arid Kenya. For three seasons, the dry matter production and grain yield of maize and beans were not increased by N fertilizer additions up to 120 kg N ha-1. Fertilizer recoveries measured by 15N isotope dilution techniques were low, less than 20%. Inoculated and uninoculated beans failed to fix N2. By contrast the cowpea derived 50% of its N from fixation, equivalent to 197 kg N ha-1. The N content of the grain generally exceeded 40 kg N ha-1, and the N content of the seeds from the grain legumes were greater than those from the cereals. Large inputs of N fertilizer or N by fixation are required if maize-grain legume cropping system in semiarid Kenya are to be sustained in the long term.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00307842
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  • 99
    Digitale Medien
    Digitale Medien
    Microbial contribution to extractable N and P after air-drying of dry tropical soils (1997)
    Springer
    Biology and fertility of soils 26 (1997), S. 31-34 
    Details
    ISSN: 1432-0789
    Schlagwort(e): Key words Microbial biomass ; Air-drying ; Extractable ; nitrogen ; Extractable phosphorus ; Tropical soil
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Geologie und Paläontologie , Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract The microbial contribution to extractable N and P after the air-drying of eight Indian dry tropical Ultisols was quantified. Air-drying of the soils decreased microbial biomass C by 25–53% but increased extractable N and P by 14–34% and 24–121%, respectively. This increase in the extractable N and P was accounted for, to some extent, by microbial biomass killed due to air-drying. Microbial biomass contributes 17–36% and 19–82% to the extractable N and P, respectively, possibly due to air-drying of the soils. I conclude that due to contamination of microbial biomass with the available nutrients in air-dried soils, measurements of extractable nutrients should be made on field-moist soils.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s003740050339
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  • 100
    Digitale Medien
    Digitale Medien
    Nodulation of African yam bean (Sphenostylis stenocarpa) by Bradyrhizobium sp. isolated from Erythrina brucei (1997)
    Springer
    Biology and fertility of soils 25 (1997), S. 209-210 
    Details
    ISSN: 1432-0789
    Schlagwort(e): Key wordsBradyrhizobium ; Sphenostylis stenocarpa ; Nitrogen fixation ; Soil reclamation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Geologie und Paläontologie , Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract African yam bean (Sphenostylis stenocarpa), which is widely cultivated in Africa because of its growth capability on marginal soils, was nodulated by an endosymbiont (characterized and designed Bradyrhizobium sp. AUEB20) isolated from the Ethiopian tree Erythrina brucei with the formation of a small number of large, indeterminate N2-fixing nodules. In contrast, 24 other isolates from Ethiopian woody legumes were ineffective. Strain AUEB20 promiscuously nodulated a number of tropical legumes, but none out of five European crop plants tested.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s003740050305
    Standort Signatur Erwartet Verfügbarkeit
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