ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
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
    Über ein Oxidchlorid des Calciums: Ca4OCl6 (1991)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 596 (1991), S. 89-92 
    Details
    ISSN: 0044-2313
    Keywords: Calcium oxychloride ; preparation ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: An Oxychloride of Calcium: Ca4OCl6Ca4OCl6 (hexagonal, P63mc, Z = 2), a = 905.8(3), c = 686.3(4) pm, (R = 0.031) crystallizes as colourless needles from reducing melts (CaCl2, Ca) that contain small amounts of „oxygen“. It contains „isolated“ tetrahedral units [Ca4O] and is isotypic with e.g., Ba4OCl6, Yb4OCl6 and K6HgS4. Ca4OCl6 does not form in the dehydration process of, for example, CaCl2 · 6 H2O.
    Notes: Ca4OCl6 (hexagonal, P63mc, Z = 2, a = 905.8(3)); c = 686.3(4) pm, (R = 0,031) kristallisiert in Form farbloser Nadeln aus „reduzierenden Schmelzen“ (CaCl2, Ca), die wenig „Sauerstoff“ enthalten. Es enthält „isolierte“ tetraedrische [Ca4O]-Einheiten und ist isotyp mit z. B. Ba4OCl6, Yb4OCl6 oder K6HgS4. Ca4OCl6 entsteht nicht beim Entwässern von z. B. CaCl2 · 6 H2O.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19915960112
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    CsNb3Br7S: Synthese, Struktur und Bindungsverhältnisse (1994)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 620 (1994), S. 863-866 
    Details
    ISSN: 0044-2313
    Keywords: CsNb3Br7S ; synthesis ; crystal structure ; bonding ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: CsNb3Br7S: Synthesis, Structure, and Bonding StatesThe reaction of NbBr5 with Nb, Cs and S in a sealed Nb container affords CsNb3Br7S at 800°C (3 days). Further on isotypic compounds of the general formula ANb3X7Ch with A = Rb, Cs; X = Cl, Br and Ch = S, Se are obtained. CsNb3Br7S crystallizes monoclinic (space group P21/a, Z = 2), with the lattice parameters a = 707.4(2), b = 1 888.4(4), c = 994.1(2) pm and β = 98.59(2)°. The crystal structure contains Nb3 clusters being linked by two additional Nb—Nb bonds to form infinite chains. Adjacent chains are bridged by Cs atoms in a cubeoctahedral coordination sphere of Br atoms. Similar with Nb3Br8 seven electrons occupy metal - metal bonding states.
    Notes: Bei der Reaktion von NbBr5 mit Nb, Cs und S bildet sich im verschweißten Niobrohr bei 800°C (3 Tage) CsNb3Br7S. Ferner wurden isotype Verbindungen der allgemeinen Zusammensetzung ANb3X7Ch mit A = Rb, Cs; X = Cl, Br und Ch = S, Se erhalten. CsNb3Br7S kristallisiert monoklin (Raumgruppe P21/a, Z = 2) mit den Gitterparametern a = 707,4(2), b = 1 888,4(4), c = 994,1(2) pm und β = 98,59(2)°. In der Kristallstruktur liegen Nb3-Cluster vor, die durch zwei zusätzliche Nb—Nb-Bindungen zu unendlichen Strängen verknüpft sind. Cs-Atome verbrücken benachbarte Stränge und besitzen eine kuboktaedrische Koordinationssphäre aus Br-Atomen. Wie in Nb3Br8 besetzen formal sieben Elektronen Metall - Metall-bindende Zustände.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19946200519
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Ein oktaedrischer Niobcluster mit sechs terminalen Azidgruppen: Die Struktur von Rb4[Nb6Br12(N3)6](H2O)2 (1995)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 621 (1995), S. 921-924 
    Details
    ISSN: 0044-2313
    Keywords: Niobium cluster azide ; synthesis ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: An Octahedral Niobium Cluster containing Six Terminal Azide Groups: The Structure of Rb4[Nb6Br12(N3)6](H2O)2Six terminal halide ligands of [Nb6Br12Br6]4- can be substituted in solution by azide ions. Single-crystals of Rb4[Nb6Br12(N3)6](H2O)2 were obtained during the evaporation of the water/methanol solvent, and structurally characterized by X-ray methods: Space group P21/c, Z = 2, a = 970.8(5) pm, b = 1525.4(7) pm, c = 1280.0(7) pm, β = 97.15(6)°. The [Nb6Br12(N3)6]4- ions contain six terminal azide groups at the corners of the octahedral niobium cluster (dNb-N = 227 pm). The [Nb6Br12(N3)6]4- ions are interconnected by Rb+ and H2O. Crystals of Rb4[Nb6Br12(N3)6](H2O)2 are explosive towards heat or mechanic pressure.
    Notes: Sechs terminal gebundene Halogenliganden von [Nb6Br12Br6]4- können in Lösung durch Azidionen ausgetauscht werden. Einkristalle von Rb4[Nb6Br12(N3)6](H2O)2 bildeten sich beim Eindunsten einer wäßrig-methanolischen Lösung und wurden röntgenographisch charakterisiert: Raumgruppe P21/c, Z = 2, a = 970,8(5) pm, b = 1525,4(7) pm, c = 1280,0(7) pm, β = 97,15(6)°. Die Struktur enthält [Nb6Br12(N3)6]4--Ionen in denen sechs terminale Azidgruppen an den Ecken des oktaedrischen Niobclusters (dNb-N = 227 pm) gebunden sind. In der Kristallstruktur liegen die [Nb6Br12(N3)6]4--Ionen verbrückt über Rb+ und H2O vor. Kristalle von Rb4[Nb6Br12(N3)6](H2O)2 reagieren auf Hitze oder mechanischen Druck explosiv.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19956210602
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    [Gd4(C2)](Cl, I)6, an Interstitially Stabilized Heteroleptic Gadolinium SesquihalideDedicated to Professor John D. Corbett on the Occasion of his 70th Birthday (1996)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 622 (1996), S. 494-500 
    Details
    ISSN: 0044-2313
    Keywords: Gadolinium sesquihalide ; interstitial carbon units ; crystal structure ; electronic structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: [Gd4(C2)](Cl, I)6, ein interstitiell stabilisiertes, heteroleptisches Gadoliniumsesquihalogenid[Gd4(C2)](Cl, I)6 erhält man aus CsI, Gd, GdCl3 und C2I4 in verschweißten Niob-Ampullen bei 1000/800°C in Form von schwarzen, glänzenden Nadeln. Die Kristallstruktur (tetragonal; P4/mbm; Z = 2; a = 1347,5(1); c = 1212,5(1) pm) ist ähnlich wie jene von Na[Mo4]O6 bzw. [Sc4B]Cl6. Trans-kantenverknüpfte [Gd6]-Oktaeder verlaufen parallel [001]. Sie enthalten interstitielle C2-Einheiten, Jedes dritte Oktaeder enthält fehlgeordnete C2-Einheiten, senkrecht zu jenen in den benachbarten [Gd6(C2)]-Oktaedern. Diese sind daher entlang der (pseudo)-C4-Achse gestaucht. Rechnungen zur elektronischen Struktur zeigen, daß insgesamt 13 Elektronen zur Auffüllung aller Metall-Metall-bindenden Zustände für eine „leere“ [Gd4]Cl6-Struktur nötig wären. Die Einlagerung der C2-Dimeren verändert die Bindungsverhältnisse in [Gd4(C2)]X6 (X = Cl, I) erheblich. Die formale Ladung von -6 der C2-Einheit wird durch das Aufsplitten der πg-Zustände reduziert, Gd—Gd und Gd—C-bindende Zustände werden besetzt und bindende dx2-y2-Orbitale kombinieren zu den am niedrigsten liegenden nicht besetzten Zuständen.
    Notes: [Gd4(C2)](Cl, I)6 is obtained from CsI, Gd, GdCl3 and C2I4 in sealed niobium containers at 1000/800°C as black, shiny needles. The crystal structure (tetragonal, P4/mbm, Z = 2, a = 1347.5(1), c = 1212.5(1) pm) is similar to that of Na[Mo4]O6 and [Sc4B]Cl6. It may be regarded as being built from octahedra sharing common trans edges running in the [001] direction. The octahedra contain C2 units as interstitials. Every third octahedron contains a disordered C2 unit perpendicular to those in the two neighboring [Gd6(C2)] octahedra and is therefore compressed in the direction of the (pseudo) C4 axis. Calculations of the electronic structure of an “empty” [Gd4]Cl6 structure reveals a total of 13 electrons necessary to occupy all metal-metal bonding states. The incorporation of a carbon dimer substantially alters the bonding conditions for [Gd4(C2)]X6 (X = Cl, I). The formal charge of -6 of the C2 unit is significantly reduced as πg states split up, Gd—Gd and Gd—C bonding states are occupied and bonding dx2—y2 orbitals combine to form the lowest unoccupied energy states.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19966220318
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Ca3Cl2CBN, eine Verbindung mit dem neuen Anion CBN4- (1991)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 594 (1991), S. 113-118 
    Details
    ISSN: 0044-2313
    Keywords: Ca3Cl2CBN ; preparation ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Ca3Cl2CBN, a Compound with the New CBN4- UnitThe new compound Ca3Cl2CBN was obtained from the reaction of Ca and CaCl2 with CaCN2, B and C or with BN and C, in sealed tantalum containers at 900°C. The crystal structure is related with the structure of Ca3Cl2C3 whereas the C34- units (C2v symmetry) are substituted by isoelectronic CBN4- anions (Cs symmetry): Ca3Cl2CBN, Pnma, a = 1 386.7(9) pm, b = 384.7(3) pm, c = 1 124.7(6) pm, Z = 4; R = 0.055, Rw = 0.036 for 380 independent intensities.The CBN4- units are located between layers of Ca2+ that are interconnected by Cl-. The bond angle (C—B—N) is 176° and bond distances are dC—B = 144 pm and dB—N = 138 pm, respectively.
    Notes: Die neue Verbindung Ca3Cl2CBN bildet sich bei der Reaktion von Ca und CaCl2 mit CaCN2, B und C oder mit BN und C in verschweißten Tantalkapseln bei 900°C. Die Kristallstruktur ist mit der Struktur von Ca3Cl2C3 verwandt, wobei statt den C34--Ionen (C2v-Symmetrie) isoelektronische CBN4--Einheiten (Cs-Symmetrie) vorliegen. Ca3Cl2CBN kristallisiert orthorhombisch (Pnma) mit: a = 1 386,7(9) pm, b = 384,7(3) pm, c = 1 124,7(6) pm, Z = 4; R = 0,055, Rw = 0,036 für 380 unabhängige Intensitäten. Die CBN4--Einheiten liegen zwischen Schichten aus Ca2+, die durch Cl- verbrückt sind. Der Bindungswinkel (C—B—N) beträgt 176°, die Bindungslängen dC—B = 144 pm und dB—N = 138 pm.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19915940113
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Thiocyanate Compounds of [Nb6Cl12]2+: The structure of A4[Nb6Cl12(NCS)6](H2O)4 (A = K, Rb, NH4)Dedicated to Professor John D. Corbett on the Occasion of his 70th Birthday (1996)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 622 (1996), S. 411-416 
    Details
    ISSN: 0044-2313
    Keywords: Niobium cluster thiocyanate ; synthesis ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Thiocyanatverbindungen von [Nb6Cl12]2+: Die Struktur von A4[Nb6Cl12(NCS)6](H2O)4 (A = K, Rb, NH4)Neue Verbindungen der allgemeinen Zusammensetzung A4[Nb6Cl12(NCS)6](H2O)4 (A = K, Rb, NH4) wurden ausgehend von Nb6Cl14 und ASCN in wäßrigen Lösungen hergestellt. Röntgenstrukturbestimmungen wurden anhand von Einkristalldaten der drei Verbindungen durchgeführt. Die Verbindungen kristallisieren isotyp in der Raumgruppe P1 (Z = 1) mit den Gitterparametern: a = 877.9(3) pm, b = 1176.6(3) pm, c = 1187.0(3) pm, α = 114.29(1)°, β = 98.96(2)°, γ = 100.91(2)° für K4[Nb6Cl12(NCS)6](H2O)4 (1); a = 887.6(3) pm, b = 1184.0(4) pm, c = 1195.4(4) pm, α = 114.95(2)°, β = 98.84(2)°, γ = 101.31(2)° für Rb4[Nb6Cl12(NCS)6](H2O)4 (2) und a = 886.0(4) pm, b = 1181.1(6) pm, c = 1183.9(6) pm, α = 114.49(2)°, β = 99.48(3)°, γ = 101.53(1)° für (NH4)4[Nb6Cl12(NCS)6](H2O)4 (3). Jedes der zentrosymmetrischen [Nb6Cl12(NCS)6]4--Ionen der isotypen Verbindungen enthält sechs Thiocyanat-Einheiten, die über Stickstoffatome an die Ecken des oktaedrischen Niobclusters gebunden sind (dNb—N = 221.5(6)-224.3(6) pm, Bindungswinkel Nb—N—C 168.6(5)-176.4(6)°). Die [Nb6Cl12(NCS)6]4--Ionen sind über A—S- und A—Cl-Wechselwirkungen der A-Kationen miteinander verbrückt. Die Hälfte der Kationen sind über zwei kristallographische Positionen fehlgeordnet.
    Notes: New compounds of the general formula A4[Nb6Cl12(NCS)6](H2O)4 (A = K, Rb, NH4) were synthesized from Nb6Cl14 and ASCN in aqueous solutions. X-ray structure refinements were performed on single-crystal data of the three compounds. They are isotypic and crystallize with the space group P1 (Z = 1) and the lattice parameters: a = 877.9(3) pm, b = 1176.6(3) pm, c = 1187.0(3) pm, α = 114.29(1)°, β = 98.96(2)°, γ = 100.91(2)° for K4[Nb6Cl12(NCS)6](H2O)4 (1); a = 887.6(3) pm, b = 1184.0(4) pm, c = 1195.4(4) pm, α = 114.95(2)°, β = 98.84(2)°, γ = 101.31(2)° for Rb4[Nb6Cl12(NCS)6](H2O)4 (2) and a = 886.0(4) pm, b = 1181.1(6) pm, c = 1183.9(6) pm, α = 114.49(2)°, β = 99.48(3)°, γ = 101.53(1)° for (NH4)4[Nb6Cl12(NCS)6](H2O)4 (3). Each centrosymmetric [Nb6Cl12(NCS)6]4- ion of the isotypic compounds contains six terminal thiocyanate groups being bound to the corners of the octahedral niobium cluster through the nitrogen atoms (dNb—N = 221.5(6)-224.3(6) pm, bond angles Nb—N—C 168.6(5)-176.4(6)°). The [Nb6Cl12(NCS)6]4- ions are linked via A—S and A—Cl interactions with the A cations. Half of the cations occur to be disordered along two crystallographic sites.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19966220306
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Trigonal-prismatische Nb6-Einheiten in Verbindungen des Typs A3[Nb6SBr17] (A = Tl, K, Cs) (1996)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 622 (1996), S. 2083-2088 
    Details
    ISSN: 0044-2313
    Keywords: Tl3[Nb6SBr17] ; Cs3[Nb6SBr17] ; K3[Nb6SBr17] ; synthesis ; crystal structure ; electronic structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Trigonal-prismatic Nb6-Units in Compounds of the Type A3[Nb6SBr17] (A = Tl, K, Cs)The new compounds A3[Nb6SBr17] (A = Tl, K, Cs) were synthesized and their lattice parameters were calculated from indexed X-ray powder patterns. An intensity measurement based on a single-crystal of Tl3[Nb6SBr17] was performed with an automatic four-circle diffractometer (a = 1704.9(1) pm, b = 1862.8(3) pm, c = 932.51(7) pm; β = 90.747(7)°, Vm = 445.9(3) cm3/mol; C2/c, Z = 4). The structure refinement confirmed consistency with the Rb3[Nb6SBr17] structure, found previously. The comparison of both structures yielded no significant differences concerning the distances within the sulfur-centered Nb6S cluster core.Extended Hückel calculations revealed a maximum of the niobium-niobium overlap populations for (the actual present number of) 14 electrons occupying metal-metal bonding states.
    Notes: Die neuen Verbindungen A3[Nb6SBr17] mit A = Tl, K, Cs wurden dargestellt und ihre Gitterkonstanten aus Röntgen-Pulverdiagrammen ermittelt. An einem Einkristall von Tl3[Nb6SBr17] wurde eine Intensitätsmessung mit einem automatischen Vierkreisdiffraktometer vorgenommen (a = 1704,9(1)pm, b = 1862,8(3)pm, c = 932,51(7)pm; β = 90,747(7)°, Vm = 445,9(3) cm3/mol; C2/c, Z = 4). Die Strukturverfeinerung bestätigte die Übereinstimmung mit der vor kurzem verfeinerten Struktur von Rb3[Nb6SBr17]. Ein Vergleich beider Verbindungen zeigt keine signifikanten Unterschiede der interatomaren Abstände für die schwefelzentrierten Nb6S-Cluster.Extended-Hückel-Berechnungen ergaben ein relatives Maximum der Niob-Niob-Überlappungspopulationen für (die tatsächlich vorliegende Anzahl von) 14 Elektronen in den Metall-Metall-bindenden Zuständen des Clusters.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19966221215
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...