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  • 1
    ISSN: 1572-8854
    Keywords: Betaine ; 4-dimethylaminopyridinioacetate ; hydrogen bonding ; crystal structure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract The crystalline dihydrate and hydrochloride trihydrate of a new betaine, namely, L·2H2O (1) and [L2H]Cl·3H2O(2) (L=p-Me2NC5H4N+CH2CO2), have been synthesized and characterized by X-ray crystallography. Molecule L in compound1 [space groupPbcn, witha=15.732(3),b=7.894(2),c=18.304(4) Å, andZ=8] possesses approximateC s symmetry. The formation of hydrogen bonds by water molecules bridging neighboring carboxy oxygen atoms leads to an infinite two-dimensional network composed of a packing of two different kinds of 12-membered rings. In compound2 [space group PT witha=7.341(2),b=9.543(2),c=17.010(4) Å, α=82.43(2)°, δ=80.34(2)°, λ=74.05(2)°, andZ=2], the carboxylate groups of a pair of betaine molecules are bridged by a proton to form a dimeric cation L2H+ with a very strong asymmetric hydrogen bond of length 2.464(7) Å. The crystal structure features a hydrogen-bonded corrugated ribbon comprising an alternate arrangement of edge-sharing centrosymmetric (H2O)4(Cl−)2 and (H2O)4 rings running parallel to thea axis.
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  • 2
    ISSN: 1572-8854
    Keywords: 2-Methylnaphthalene ; hexachlorocyclopentadiene ; crystal structure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract 2-Methylnaphthalene undergoes Diels-Alder addition and substitution with hexachlorocyclopentadiene to give two products, 1,2,3,4,5,6,7,8,13,13,14,14-dodecachloro-1,4,4a,4b,5,8,8a,12b-octahydro-10-methyl-1,4;5,8-dimethanotriphenylene 1 and 1,2,3,4,5,6,7,8,13,13,14,14-dodecachloro-1,4,4a,4b,5,8,8a,12b-octahydro-10-(1′,2′,3′,4′,5′-pentachlorocyclopentadienyl)methyl-1,4;5,8-dimethanotriphenylene 2. The molecular structure of 2 has been characterized by X-ray crystallography: C26H9Cl17, monoclinic, space group P21/c, with a = 15.316(3), b = 13.698(3), c = 16.116(3) Å, β = 96.113(3)°, and Z = 4.
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  • 3
    ISSN: 1572-8854
    Keywords: Copper(II) complex ; crystal structure ; coordination polymer ; betaine ; dicarboxylate ligand
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract Three polymeric copper(II) complexes of a flexible double betaine, namely, [{Cu(L)Cl2(H2O)} n ]·2 n H2O (1), [{Cu(L)Br2(H2O)} n ]·2nH2O (2), and [{Cu(L)(H2O)4} n ](ClO4)2n ·2nH2O (3) [L=−O2CCH(Me3N+)CH2CH2CH(Me3N+CO2], have been prepared and characterized by singlecrystal X-ray analysis. Isomorphous complexes (1) and (2) crystallize in space groupC2/c (No. 15) witha=17.725(3),b=5.958(2),c=19.077(3) Å, β=110.70(1)o,V=1881.4(4) Å3, Z=4 anda=18.268(4),b=5.948(3),c=19.166(5) Å, β=109.08(2)o,V=1964.7(9) Å3, Z=4, respectively. Complex (3) belongs to space groupPĪ (No. 2) witha=6.203(1),b=9.293(2),c=12.035(2) Å, α=86.56(2), β=87.33(3), γ=71.23(2)o,V=655.4(2) Å3 and Z=1. The crystal structure of (1) and (2) features an infinite zigzag chain composed of an alternate arrangement of metal atoms and double betaines ligands, with each Cu(II) atom in a distorted CuX2O3 [X-Cl, Br] square-pyramidal geometry, and hydrogen bonding between adjacent chains leads to a layer structure concentrated the (200) family of planes. Complex (3) exhibits a layer structure corresponding to the (001) family of planes, in which neighboring chains constructed from the metal atoms and the double betaine ligands are cross-linked by hydrogen bonding between the aqua ligands. The Cu(II) atom is coordinated in a CuO6 octahedral geometry with Jahn-Teller distortion.
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Journal of chemical crystallography 26 (1996), S. 553-557 
    ISSN: 1572-8854
    Keywords: Silver(I) complex ; synthesis ; crystal structure ; spectroscopic properties
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract The reaction of [Ph3PAgI]4 with sodium phenylacetate in MeOH and CH2Cl2 at room temperature gave rise to a binuclear silver complex with triphenylphosphine and phenylacetate mixed ligands, [Ph3PAg(O2CCH2Ph)]2. The crystal and molecular structure of the complex has been determined by single crystal X-ray diffraction analysis. The space group is $$P\bar 1$$ witha=9.198(2),b=9.516(2),c=13.842(3) Å, α=102.00(3), β=108.34(3), γ=93.58(3)°,Z=1, andDc=1.506 g cm−3. The silver atoms are each coordinated by one phosphorus atom from triphenylphosphine and two oxygen atoms from the carboxylate groups in a T-shape. The complex is further characterized by its IR,1H, and31P NMR spectra.
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  • 5
    ISSN: 1572-9001
    Keywords: Isocinchomeronic acid ; 2,5-pyridinedicarboxylic acid ; hydrogen isocinchomeronate ; manganese(II) complex ; crystal structure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The reactions between Mn(II), Co(II), Ni(II), and Zn(II) ions with isocinchomeronic acid (H2-isocin) afforded complexes of the general formula M(H-isocin)2-2H2O, whereas Fe(II) gives both red and deep red-brown products of the same formula. Various physical measurements suggest that the complexes of M = Co, Ni, Zn, and Fe (brown) are octahedrally coordinated by two aqua ligands and twotrans-N,O-bidentate H-isocin− anions with dimeric hydrogen bonding. Those for M = Mn and Fe (red) are the correspondingcis isomers. The structure of the manganese complex as determined by X-ray crystallography exhibitsC 2 molecular symmetry with Mn-N = 2.279(2), Mn-O(H-isocin)− = 2.196(2), and Mn-O(aqua) = 2.137(2) Å. Each aqua ligand forms two donor O-H ⋯ O hydrogen bonds with carboxy groups of different molecules in adjacent chains.
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Journal of chemical crystallography 26 (1996), S. 403-406 
    ISSN: 1572-8854
    Keywords: Cyclotrithiazene ; arylaminophospine ; crystal structure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract The title compound (C6H5)2(OC4H8N)P=N−S3N3 crystallizes in the space group $$P\bar 1$$ with unit cell parametersa=9.3900(2),b=9.4747(1),c=11.3850(3) Å, α=95.73(4), β=96.85(6), γ=104.26(2)o, and Z=2. The tricoordinated sulfur of the cyclotrithiazene ring deviates from the mean plane of other skeletal atoms by 0.683(4) Å. The angle at this atom is the smallest in the ring and is enclosed by the longest S−N bonds observed in the ring.
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  • 7
    ISSN: 1572-9001
    Keywords: Betaine ; sodium perchlorate ; crystal structure ; polymeric framework
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Three crystalline complexes of sodium perchlorate with different flexible double betaines [Na 2(L1)(ClO4)(H2O) n ](ClO4) n (1), [Na 3(L2)(ClO4)3(H2O)2 n ] (2), and [Na(L 3)(CH3OH)n]-(ClO4) n ·xnH2O (x=0.25) (3) [−O2CCH2N+Me2−(CH2) n -N+Me2CH2CO2 −,n=2 L1;n=3 L2;n=4 L3] have been synthesized and characterized by single-crystal X-ray structure analysis. Complex (1) comprises tetranuclear sodium units consolidated by betaine and aqua ligands, which are bridged by half of the ClO4 − anions to form layers matching the (200) planes, the remaining uncoordinated ClO4 − anions being accommodated between adjacent layers. Complex (2) possesses a double-layer polymeric structure with the sodium atoms bridged by ligand oxygen atoms to form columns running parallel to thea axis, which are interconnected by double-betaine ligands lying parallel to theac plane. All of the ClO4 − groups and water molecules are coordinated to the metal atoms. In complex (3) the chains composed of alternating eight-membered and four-membered metallocycles are cross-linked by the betaine ligands, which lie in the (020) and (01/1) families of planes, to yield a three-dimensional network. All of the ClO4 − groups and water molcules fill the resulting infinite channels running parallel to thea axis. Two unusual carboxylate coordination modes are identified, namelyμ 3-O andhapto-3-O plushapto-2-O′ in (1) and (2), respectively.
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  • 8
    ISSN: 1573-1111
    Keywords: crystal structure ; hydroquinone ; p-terphenyl ; dihydroanthracene ; hydrogen bonding ; host-guest compound ; molecular complex ; adduct
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The title compounds crystallize in space groupC2/c withZ=4; C18H12O2Cl2·HO(CH2)4OH,a=16.186(3),b=7.626(1),c=16.939(3) Å, β=91.32(2)°,R F =0.048 for 1743 observed MoKα reflections; C26H20O2·HO(CH2)4OH,a=11.881(3),b=13.009(4),c=16.689(4) Å, β=110.67(2)°,R F =0.066 for 1783 data points. Both structures feature centrosymmetric hydrogen-bonded (OH)4 rings formed by molecular components located in special positions. Different packing modes account for the observed conformations (g + ag − andaaa, respectively) of 1,4-butanediol and its possible replacement by 1,2-ethanediol as a guest in the former crystal structure.
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  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Journal of inclusion phenomena and macrocyclic chemistry 6 (1988), S. 461-471 
    ISSN: 1573-1111
    Keywords: N,N′-dicyclohexylpiperazine ; N-oxide, hydrate ; crystal structure ; hydrogen bonding
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract N,N′-DicyclohexylpiperazineN,N′-dioxide octahydrate, C16H46N2O10,M r=426.55, monoclinic, space groupC2/m (No. 12),a=12.961(4),b=11.533(4),c=7.907(1) Å, β=98.37(2)o,V=1169.3(6) Å3,Z=2. The structure was solved by the direct method and refined toR=0.045 for 1192 observed MoK α reflections. TheN,N′-dioxide molecule occupies a site of symmetry 2/m. The piperazine ring takes the chair form with the two N−O bonds oriented axially in atrans configuration. Hydrogen bonding between the water molecules, as well as between theN-oxide groups and water molecules, gives rise to a puckered layer composed of edge-sharing four-membered, five-membered, six-membered, and eight-membered rings. Adjacent layers are cross-linked by theN,N′-dicyclohexylpiperazine moieties lying between them, thereby generating a ‘sandwich’ structure consolidated by covalent and hydrogen bonding.
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  • 10
    ISSN: 1434-1948
    Keywords: Tungsten complexes ; Molybdenum complexes ; Tetradentate ligands ; Oxygen-atom transfer ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A series of N2O2 tetradentate ligands with a range of substituents attached to the nitrogen atoms have been prepared (H2Ln) (n = 1-9). Treatment of these ligands and the N2S2 tetradentate ligand H2L10 with [WO2Cl2(DME)] (DME = 1,2-dimethoxyethane) in the presence of triethylamine leads to the formation of cis-dioxotungsten(VI) complexes [WO2(Ln)] (n = 1-10). Reaction of the N2O2 tetradentate ligands H2Ln (n = 1, 3-7) with ammonium molybdate tetrahydrate and dilute hydrochloric acid gives the corresponding molybdenum(VI) analogs [MoO2(Ln)] (n = 1, 3-7). These compounds have been spectroscopically characterized and the molecular structures of [WO2(Ln)] (n = 1, 2, 9) and [MoO2(L5)] have been established by X-ray diffraction analysis. These high-valent compounds participate in oxygen-atom transfer reactions and can catalyze the oxidation of benzoin with dimethyl sulfoxide. The complex [WO2(L10)], which contains an S-donor ligand, has lower reduction potential and higher reactivity toward oxo-transfer reactions than analogous tungsten complexes having N2O2 ligands. The kinetics of these catalytic processes along with the structure and electrochemistry of these dioxotungsten and -molybdenum complexes are described and compared.Supporting information for this article is available on the WWW under http://www.wiley-vch.de/contents/jc_2005/1999/98246_s.pdf or from the author.
    Additional Material: 7 Ill.
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