ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 117 (1984), S. 2547-2554 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis and Crystal Structure of 3-(Lithiomethyl)-1,1,2,2-tetramethylcyclopropane, a Stable Cyclopropylmethyllithium CompoundThe cyclic chlorine and mercury compounds 6 and 9 as well as the open-chain chloro compound 7 react with lithium power in diethyl ether to afford the pure cyclopropylmethyllithium compound 10 completely free of diethyl ether. Only at - 60°C starting with 7 besides 10.8% of the corresponding open-chain organolithium compound 11 was detected. X-ray analysis of 10 showed solvent-free hexameric clusters with the lithium atoms forming a trigonal antiprism with unoccupied trianglular faces on the top and at the bottom while each of the six laterally triangular faces is coordinated to a 2,2,3,3-tetramethylcyclopropylmethyl ligand.
    Notes: Sowohl die cyclischen Chlor- und Quecksilberverbindungen 6 und 9 als auch die offenkettige Chlorverbindung 7 liefern bei der Umsetzung mit Lithiumpulver in Diethylether die reine etherfreie Cyclopropylmethyllithium-Verbindung 10. Nur bei - 60°C lassen sich ausgehend von 7 noch 8% der entsprechenden offenkettigen Lithiumverbindung 11 neben 10 nachweisen. Die Röntgenstrukturanalyse von 10 ergab hexamere Cluster, in denen die Lithiumatome ein trigonales Antiprisma bilden, dessen obere und untere Dreiecksfläche unbesetzt ist, während über jeder der sechs seitlichen Dreiecksflächen ein 2,2,3,3-Tetramethylcyclopropylmethyl-Rest koordiniert ist.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Proton Resonance Spectroscopy of Unsaturated Ringsystems, XXIX. Simple Synthesis of Benzocyclooctene by Protonation of Biphenylene DianionBiphenylene dianion (1) reacts with H2O to give 4a,8b-dihydrobiphenylene (3) that opens thermally to give benzocyclooctene (4) (yield 〉 80%). At 0°C 3 has a half life of 1 min. The activation parameters of the rearrangement 3 → 4 are δH* = 78.8 ± 5.0 kJ/mol and δS* = - 7.3 ± 8.7 j/mol K. 3 reacts with maleic anhydride to give a Diels-Alder adduct, whose structure has been determined by X-ray analysis.
    Notes: Biphenylen-Dianion (1) reagiert mit H2O zu 4a,8b-Dihydrobiphenylen (3). das thermisch zu Benzocylcoocten (4) öffnet (Ausb. 〉 80%). Bei 0°C besitzt 3 eine Halbwertszeit von 1 min. Die Aktivierungsparameter der Umlagerung 3 → 4 betragen δH* = 78.8 ± 5.0 kJ/mol und δS* = - 7.3 ± 8.7 J/mol K. 3 liefert mit Maleinsäureanhydrid ein Diels-Alder-Addukt, dessen Struktur röntgenographisch bestimmt wurde.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 0044-2313
    Keywords: Phosphorus sulfides ; 31P NMR spectroscopy ; phosphorus sulfur melts ; tetra phosphorus hexasulfide ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The Molecular Composition of Solidified Phosphorus-Sulfur Melts and the Crystal Structure of β-P4S6Phosphorus sulfur melts were annealed for one week at 673 K and then quenched in ice water. The solids were dissolved in CS2 and the concentrations of phosphorus sulfides were determined by 31P NMR spectroscopy. Samples containing between 44 and 70 mol% sulfur dissolved completely in CS2. Between 0 and 42 mol% remains an insoluble residue of red phosphorus. Above 72 mol% it consisted of sulfur chains linked by phosphorus atoms. The solutions contained mainly the congruently melting compounds P4S3, P4S7, and P4S10 having maximum concentrations at their stoichiometric compositions. Other compounds P4Sn (n = 4-9) which decompose on heating, according to the phase diagram, were also found in surprisingly high concentrations. One of these was β-P4S6 which crystallizes in the monoclinic space group P21/c with the lattice parameters a = 702.4(2), b = 1 205.6(2), c = 1 148.9(6) pm and β = 103.4(2)°.Reaction of white phosphorus with sulfur was also investigated. In contrast to the results of previous authors, who described the system P4-S8 below 373 K as eutectic, we found that the elements reacted below this temperature.
    Notes: Phosphor-Schwefel-Schmelzen wurden eine Woche bei 673 K getempert und anschließend in Eiswasser abgeschreckt, dann in CS2 gelöst und die Konzentration der Phosphorsulfide mit Hilfe der 31P-NMR-Spektroskopie bestimmt. Proben mit Zusammensetzungen zwischen 44 und 70 Mol-% Schwefel lösten sich vollständig auf. Zwischen 0 und 42 Mol-% Schwefel traten als unlöslicher Rückstand roter Phosphor, oberhalb von 72 Mol-% Schwefel über Phosphoratome vernetzte Schwefelketten auf. Die löslichen Bestandteile waren hauptsächlich die kongruent schmelzenden Verbindungen P4S3, P4S7 und P4S10. Die maximalen Konzentrationen lagen bei den jeweiligen stöchiometrischen Zusammensetzungen. Andere P4Sn (n = 4-9) Verbindungen, deren Molekülkristalle sich beim Erwärmen peritektisch oder peritektoid zersetzen, wurden ebenfalls mit höheren Konzentrationen gefunden, dazu gehörte β-P4S6, das in der monoklinen Raumgruppe P21/c mit den Gitterkonstanten a = 702,4(2), b = 1 205,6(2), c = 1 148,9(6) pm und β = 103,4(2)° kristallisiert.Die Reaktion von weißem Phosphor mit Schwefel wurde ebenfalls untersucht. Im Gegensatz zu Angaben anderer Autoren, die das P4-S8-System unterhalb von 373 K als einfach eutektisch beschreiben, wurden in diesem Temperaturbereich Reaktionen zwischen den Komponenten beobachtet.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    ISSN: 0044-2313
    Keywords: Selenites ; hydrates ; X-ray ; IR ; crystal structure ; pseudosymmetry ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Polymorphic and Pseudosymmetrical Hydrates MSeO3 · H2O (M = Mn, Co, Ni, Zn, Cd)By crystallization from aqueous solutions of MSeO3 and M(HSeO3)2, the selenites MSeO3 · H2O (M = Mn, Co, Ni, Zn, Cd) were obtained and characterized by means of X-ray diffraction and IR-spectroscopy. The crystal structure of ZnSeO3 · H2O was determined. The IR spectra indicate that the hydrates are isotypic and contain H2O molecules of symmetry mm2. However, the X-ray data show different structure types with H2O molecules of site symmetry m or 1. CdSeO3 · H2O and MnSeO3 · H2O are isotypic (o.rh., MnSeO3 · D2O type). CoSeO3 · H2O (mon.) as well as the isotypic NiSeO3 · H2O and ZnSeO3 · H2O (mon.) form new structure types. These findings are discussed on the basis of the crystal structure of ZnSeO3 · H2O (P21/n, a = 477.9(1), b = 1319.4(5), c = 570.1(1) pm, β = 90.84(2)°, Z = 4, Dx = 3.886 g · cm-3, R = 0.035 for 722 reflections with I 〉 2σ1) and the local pseudosymmetry of its components, i.e., layers ∞2[ZnSeO3 · H2O] of ZnO6 octahedra sharing four equatorial vertices, SeO32- anions and H2O molecules.
    Notes: Durch Kristallisation aus MSeO3- und M(HSeO3)2-Lösungen wurden die Selenite MSeO3 · H2O (M = Mn, Co, Ni, Zn, Cd) erhalten und röntgenographisch sowie IR-spektroskopisch charakterisiert. Von ZnSeO3 · H2O wurde die Kristallstruktur bestimmt. Die IR-Spektren deuten auf Isotypie der Hydrate und H2O-Moleküle der Symmetrie mm2. Die Röntgenbeugungsdaten zeigen dagegen das Vorliegen verschiedener Strukturtypen mit H2O-Molekülen der Lagesymmetrie m oder 1. CdSeO3 · H2O und MnSeO3 · H2O sind isotyp (o.rh., MnSeO3 · D2O-Typ). CoSeO3 · H2O (mon.) sowie die isotypen NiSeO3 · H2O und ZnSeO3 · H2O (mon.) kristallisieren in neuen Strukturtypen. Diese Befunde werden auf der Basis der Kristallstruktur von ZnSeO3 · H2O (P21/n, a = 477,9(1), b = 1319,4(5), c = 570,1(1) pm, β = 90,84(2)°, Z = 4, Dx = 3,886 g · cm-3, R = 0,035 für 722 Reflexe mit I 〉 2σ1) und der lokalen Pseudosymmetrie ihrer Bausteine (Schichten ∞2[ZnSeO3 · H2O] aus vierfach eckenverknüpften ZnO6-Oktaedern, SeO32--Anionen und H2O-Moleküle) diskutiert.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: In den Systemen FeSO3—H2O und NiSO3—H2O konnten folgende Hydrate erhalten werden: α-FeSO3 · 3H2O, γ-FeSO3 · 3H2O, FeSO3 · 2,5 H2O, FeSO3 · 2 H2O, NiSO3 · 6 H2O, NiSO3 · 3 H2O, NiSO3 · 2,5 H2O und NiSO3 · 2 H2O. Die Gitterdaten der folgenden Hydrate wurden anhand von Einkristallmessungen bestimmt: γ-FeSO3 · 3 H2O: a = 965,9(1), b = 557,1(1), c = 944,7(1) pm, Z = 4, FeSO3 · 2 H2O (P21/n): a = 645,6(1), b = 863,1(1), c = 761,2(1) pm, β = 99,84(1)°, Z = 4, NiSO3 · 3 H2O: a = 945,0(1), b = 547,2(1), c = 932,5(1) pm, Z = 4, NiSO3 · 2,5 H2O (P41212): a = b = 935,3(1), c = 1016,6(1) pm, Z = 8, NiSO3 · 2 H2O (P21/n): a = 631,4(1), b = 851,0(1), c = 744,7(1) pm, β = 98,91(1)°, Z = 4. Die IR- und Raman-Spektren sowie das Ergebnis thermoanalytischer Messungen (DTA, DTG, Röntgenheizaufnahmen) werden mitgeteilt. Die bei Sulfiten und Sulfithydraten zweiwertiger Metalle bisher beobachteten Strukturtypen werden diskutiert.Sulfites and Sulfite Hydrates of Iron and Nickel. X-ray, Thermoanalytical, I.R., and Raman DataIn the systems FeSO3—H2O and NiSO3—H2O the following hydrates have been found: α-FeSO3 · 3H2O, γ-FeSO3 · 3H2O, FeSO3 · 2,5 H2O, FeSO3 · 2 H2O, NiSO3 · 6 H2O, NiSO3 · 3 H2O, NiSO3 · 2,5 H2O and NiSO3 · 2 H2O. The following crystal data have been determined by single crystal measurements: γ-FeSO3 · 3 H2O: a = 965,9(1), b = 557,1(1), c = 944,7(1) pm, Z = 4, FeSO3 · 2 H2O (P21/n): a = 645,6(1), b = 863,1(1), c = 761,2(1) pm, β = 99,84(1)°, Z = 4, NiSO3 · 3 H2O: a = 945,0(1), b = 547,2(1), c = 932,5(1) pm, Z = 4, NiSO3 · 2,5 H2O (P41212): a = b = 935,3(1), c = 1016,6(1) pm, Z = 8, NiSO3 · 2 H2O (P21/n): a = 631,4(1), b = 851,0(1), c = 744,7(1) pm, β = 98,91(1)°, Z = 4. IR, Raman, and thermoanalytical (DTA, DTG, high temperature X-ray) data are presented. The structure types found for sulfites and sulfite hydrates of bivalent metals are discussed.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Anhydrous Sulfites of Strontium, Barium, Lead, Cadmium, and Manganese. Preparation of Single Crystals by Gel Crystallisation. X-ray, Thermoanalytical, I. R., and Raman DataSingle crystals of the anhydrous sulfites BaSO3, CdSO3-I, PbSO3, and Na2Cd3(SO3)4, and the hitherto unknown sulfites CdSO3-II and CdSO3-III have firstly been obtained by gel crystallization technique. Crystal data determined by single crystal measurements see „Inhaltsübersicht“.I. R., Raman, and thermoanalytical (DTA, TG, DTG, high temperature X-ray) data are presented and discussed. CdSO3-I is the thermodynamically stable form of the three polymorphic cadmium sulfites at ambient temperature.
    Notes: Durch Gelkristallisation in einem Kieselsäuregel konnten erstmals Einkristalle der wasserfreien Sulfite BaSO3, CdSO3-I, PbSO3 und Na2Cd3(SO3)4 sowie der bisher nicht bekannten Sulfite CdSO3-II und CdSO3-III erhalten werden. Die Gitterdaten folgender Sulfite wurden anhand von Einkristallmessungen bestimmt: SrSO3 und BaSO3 (P21/m): a = 634,4(1), b = 526,7(1), c = 443,3(1) pm, β = 106,51(1)° und a = 664,9(1), b = 549,0(1), c = 464,7(1) pm, β = 106,25(1)°, Z = 2, PbSO3 (Pnma): a = 790,3(1), b = 548,8(1), c = 680,2(1) pm, Z = 4, CdSO3-I (P21/c): a = 443,9(1), b = 860,8(1), c = 718,3(1) pm, β = 94,53(1)°, Z = 4, CdSO3-II (P21/c): a = 554,7(1), b = 1254,2(1), c = 849,9(1) pm, β = 100,00(1)°, Z = 8, CdSO3-III (R3): a = 814,5(1) pm, α = 109,04(1)°, Z = 6, Na2Cd3(SO3)4 (C2/c, Cc): a = 1612,8(2), b = 537,2(1), c = 1293,6(1) pm, β = 90,17(1)°, Z = 4. Die IR- und Ramanspektren sowie das Ergebnis thermoanalytischer Messungen (DTA, TG, DTG, Röntgenheizaufnahmen) werden diskutiert. Von den drei polymorphen Cadmiumsulfiten ist CdSO3-I die bei Raumtemperatur thermodynamisch stabile Form.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On Hydrates of the Type MX2 · 1 H2O with M = Sr, Ba and X = Cl, Br, I. Crystal Structures of Strontium Chloride Monohydrate, SrCl2 · 1 H2O, and Strontium Bromide Monohydrate, SrBr2 · 1 H2OThe structures of SrCl2 · 1 H2O, orthorhombic, Pnma, a = 1088.1(1), b = 416.2(1), c = 886.4(1) pm, Z = 4, dc = 2.92 Mg m-3, R = 0.052 for 755 reflections, and of SrBr2 · 1 H2O, orthorhombic, Pnma, a = 1146.4(1), b = 429,5(1), c = 922.9(1) pm, Z = 4, dc = 3.88 Mg m-3, R = 0.056 for 762 reflections have been determined from a Patterson synthesis and refined by Fourier and Least Squares methods. The structure consists of [SrX2 = H2O]n-layers normal to [100] and Sr—H2O—Sr—H2O-chains parallel [010]. The Sr—O distances are 265.1(3) pm, SrCl2 · 1 H2O, and 265.9(4) pm, SrBr2 · 1 H2O. The shortest Sr—Cl and Sr—Br distances (298.9(1) and 315.3(1) pm) are within the layers. The environment of oxygen and strontium is a distorted tricapped trigonal prism. The orientation of the water molecules has been determined from vibrational spectroscopic measurements. The hydrogen atoms H1 and H2 form bifurcated hydrogen bonds of different strength to neighbouring halide ions. The corresponding O···X distances are 331.9(4) and 320.2(4) pm, SrCl2 · 1 H2O, and 340.8(4) and 333.8(4) pm, SrBr2 · 1 H2O. The other O—X distances are between 310.3(5) and 323.7(5) pm, SrCl2 · 1 H2O, and 323.5(5) and 333.2(6) pm, SrBr2 · 1 H2O.
    Notes: Die Strukturen des SrCl2 · 1 H2O, orthorhombisch, Pnma, a = 1088,1(1), b = 416,2(1), c = 886,4(1) pm, Z = 4, drö = 2,92 Mg m-3, R = 0,052 für 755 Reflexe und des SrBr2 · 1 H2O, orthorhombisch, Pnma, a = 1146,4(1), b = 429,5(1), c = 922,9(1) pm, Z = 4, drö = 3,88 Mg m-3, R = 0,056 für 762 Reflexe wurden nach der Schweratommethode bestimmt und mit Fourier- und Least-squares-Verfahren verfeinert. Die Struktur besteht aus [SrX2 · H2O]n-Schichten senkrecht [100] mit Sr—H2O—Sr—H2O-Zick-Zack-Ketten parallel [010]. Die Sr—O-Abstände betragen 265,1(3) pm beim SrCl2 · 1 H2O und 265,9(4) pm beim SrBr2 · 1 H2O. Die kürzesten Sr—Cl- und Sr—Br-Abstände (298,9(1) bzw. 315,3(1) pm) liegen innerhalb der Schichten. Die Umgebung des Sauerstoffs und des Strontiums ist verzerrt tricapped-trigonal-prismatisch. Die Orientierung der Kristallwassermoleküle konnte mit Hilfe schwingungsspektroskopischer Messungen bestimmt werden. Die Wasserstoffatome H1 und H2 bilden verzweigte, unterschiedlich starke Wasserstoffbrücken zu benachbarten Halogenidionen aus. Die entsprechenden O···X-Abstände sind 331,9(4) und 320,2(4) pm beim SrCl2 · 1 H2O bzw. 340,8(4) und 333,8(4) pm beim SrBr2 · 1 H2O. Die übrigen O—X-Abstände liegen zwischen 310,3(5) und 323,7(5) pm beim SrCl2 · 1 H2O bzw. 323,5(5) und 333,2(6) pm beim SrBr2 · 1H2O.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: NaM2OH(SO3)2 · 1 H2O with M = Mg, Mn, Fe, Co, Ni, and Zn. A New Class of Basic SulfitesHitherto unknown hydroxide sulfites of the type NaM2OH(SO3)2 · 1 H2O with M = Mg, Mn, Fe, Co, Ni, and Zn have been obtained by crystallization from aqueous sulfite solutions containing Na+ and M2+ ions. Crystal structure, IR and Raman data, and the results of thermoanalytical studies are reported and discussed. The hydroxide sulfites show a strongly anisotropic thermal expansion due to the layer structure and exhibit an unusually high thermal stability compared to other solid hydrates. The magnesium compound, for example, decomposes at 355°C. The crystal data of the triclinic compounds see “Inhaltsübersicht”.
    Notes: Durch Kristallisation aus natriumhaltigen wässerigen Sulfitlösungen wurden bisher nicht bekannte Hydroxidsulfite des Typs NaM2OH(SO3)2 · 1 H2O mit M = Mg, Mn, Fe, Co, Ni und Zn erhalten. Die Kristallstruktur, die IR- und Ramanspektren sowie das Ergebnis thermoanalytischer Untersuchungen werden mitgeteilt und diskutiert. Die Verbindungen zeigen aufgrund ihrer Schichtenstruktur eine stark anisotrope thermische Ausdehnung. Sie besitzen eine für Hydrate ungewöhnlich große thermische Stabilität. Die Magnesiumverbindung zersetzt sich z. B. erst oberhalb von 355°C. Die Verbindungen des Typs NaM2OH(SO3)2 · 1 H2O kristallisieren triklin (P1, Z = 2) mit folgenden Gitterdaten: M = Mg: a = 890,5(1), b = 784,5(1), c = 631,5(1) pm, α = 113,28(2)°, β = 110,41(1)°, γ = 98,00(2)°, M = Mn: a = 907,6(1), b = 795,7(1), c = 648,7(1) pm, α = 112,71(1)°, β = 109,34(1)°, γ = 99,23(1)°, M = Fe: a = 898,8(1), b = 789,0(1), c = 634,8(1) pm, α = 112,06(1)°, β = 109,59(1)°, γ = 99,76(1)°, M = Co: a = 888,0(1), b = 783,7(1), c = 631,6(1) pm, α = 112,61(1)°, β = 109,85(1)°, γ = 98,93(1)°, M = Ni: a = 878,4(2), b = 777,0(3), c = 626,3(1) pm, α = 112,54(2)°, β = 109,84(2)°, γ = 99,47(3)°, M = Zn: a = 887,4(1), b = 785,2(1), c = 629,9(1) pm, α = 112,27(1)°, β = 109,67(1)° und γ = 99,66(1)°.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    ISSN: 0044-2313
    Keywords: Hydrogen selenites ; crystal structure ; IR ; Raman heating ; thermal analysis ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On the Hydrates M(HSeO3)2 · 4H2O (M = Mg, Co, Ni, Zn) - Crystal Structures, IR, Raman, and Thermoanalytical InvestigationsFrom aqueous solutions of M(HSeO3)2 single crystals of Mg(HSeO3)2 · 4H2O and of the hitherto unknown compounds Co(HSeO3)2 · 4H2O, Ni(HSeO3)2 · 4H2O and Zn(HSeO3)2 · 4H2O could be obtained. The crystal structures, X-ray powder, IR, Raman and thermoanalytical (DTA, TG, Raman heating) data are presented and discussed. The crystal data of the isotypic compounds are: monoclinic, space group C2/c, Z = 4, Mg: a = 1 464.6(2), b = 755.3(1), c = 1 099.9(1) pm, β = 126.59(1)°, V = 0.9769(1) nm3, Co: a = 1 462.5(2), b = 756.5(2), c = 1 102.2(2) pm, β = 126.53(1)°, V = 0.9798(2) nm3, Ni: a = 1 452.2(2), b = 751.0(1), c = 1 091.5(1) pm, β = 126.28(1)°, V = 0.9595(1) nm3, Zn: a = 1 468.3(2), b = 755.8(1), c = 1 103.1(1) pm, β = 126.79(1)°, V = 0.9804(2) nm3. The crystal structures consist of hexagonal packed [M(HSeO3)2 · 2H2O]n chains of [MO4(H2O)2] octahedra linked by Se atoms. They contain trigonal pyramidal SeO2OH-ions with “free” hydroxyl groups and also “free” molecules of water of crystallization. The hydroxyl groups build strong H-bonds (O—H … O distances: 265-268 pm). The IR spectra show AB doublett bands in the OH stretching mode region of the hydroxyl groups. The water molecules of crystallization are linked to planar (H2O)4 tetramers by H-bonds with unusually short O—H … O bond distances of 271-273 pm. DTA and TG measurements indicate that thermal decomposition results in the direct formation of the respective diselenite MSe2O5. Raman heating measurements show under quasi static conditions the intermediate formation of the anhydrous hydrogen selenites.
    Notes: Aus M(HSeO3)2-Lösungen konnten erstmals Einkristalle von Mg(HSeO3)2 · 4H2O sowie die bisher nicht bekannten Verbindungen Co(HSeO3)2 · 4H2O, Ni(HSeO3)2 · 4H2O und Zn(HSeO3)2 · 4H2O erhalten werden. Die Kristallstrukturen, Röntgenpulverdaten, IR- und Raman-Spektren sowie die Ergebnisse thermoanalytischer (DTA, TG, Raman-Heizaufnahmen) Untersuchungen werden mitgeteilt und diskutiert. Die Kristalldaten der isotypen Verbindungen sind: monoklin, Raumgruppe C2/c, Z = 4, Mg: a = 1 464,6(2), b = 755,3(1), c = 1 099,9(1) pm, β = 126,59(1)°, V = 0,9769(1) nm3, Co: a = 1 462,5(2), b = 756,5(2), c = 1 102,2(2) pm, β = 126,53(1)°, V = 0,9798(2) nm3, Ni: a = 1 452,2(2), b = 751,0(1), c = 1 091,5(1) pm, β = 126,28(1)°, V = 0,9595(1) nm3, Zn: a = 1 468,3(2), b = 755,8(1), c = 1 103,1(1) pm, β = 126,79(1)°, V = 0,9804(2) nm3. Die Kristallstrukturen bestehen aus hexagonal gepackten [M(HSeO3)2 · 2H2O]n-Ketten Se-verbrückter [MO4(H2O)2]-Oktaeder. Sie enthalten trigonal pyramidale SeO2OH--Ionen mit „freien“ Hydroxylgruppen und „freie“ Kristallwassermoleküle. Die Hydroxylgruppen bilden starke H-Brücken (O—H … O-Abstände: 265-268 pm). Die IR-Spektren zeigen im Bereich der OH-Streckschwingungen der Hydroxylgruppen AB-Doublett-Banden. Die Kristallwassermoleküle sind zu planaren (H2O)4-Tetrameren mit ungewöhnlich kurzen O—H … Ow-Abständen (271 - 273 pm) H-verbrückt. Die thermische Zersetzung führt nach DTA- und TG-Messungen direkt zum jeweiligen Diselenit MSe2O5. Mittels Raman-Heizaufnahmen unter Quasi-Gleichgewichtsbedingungen konnte erstmals die intermediäre Bildung wasserfreier Hydrogenselenite beobachtet werden.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    ISSN: 0377-0486
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The Raman and infrared spectra of MgSO3·3H2O and of deuteriated and isotopically dilute samples of this hydrate were recorded from 100 to 4000 cm-1 at 90-300 K and analysed with regard to the bonding structure of the water of crystallization, the space group of this compound, i.e. P212121, Pnma or Pn21a, and assignment and coupling (with the H2O and D2O librations) of the internal modes of the sulphite ions. The orientational behaviour of single crystal Raman studies on isotopically dilute samples are firstly used for assigning the uncoupled OH (OD) stretching modes to the H positions in the lattice. From the three types of water of crystallization (in the case of space group P212121 or Pn21a), the orientationally disordered H2O1 and H2O11 are involved in very strong hydrogen bonds, uncoupled OH (OD) modes 3027 (2282) and 2930 (2240) cm-1, caused by the strong hydrogen bond acceptor strength of the sulphite ions. Both water molecules are extremely distorted with OH (OD) mode splittings up to 393 (218) cm-1, the largest known so far. H2O111 forms weak bifurcated hydrogen bonds. Both the stretching and bending vibrations of the sulphite ions coincide with rotational modes of the water molecules.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...