Synthese,Kristallstruktur und spektroskopische Charakterisierung von [Au12(PPh)2(P2Ph2)2(dppm)4Cl2]Cl2

Synthesis, Crystal Structure and Spectroscopic Characterization of [Au₁₂(PPh)₂(P₂Ph₂)₂(dppm)₄Cl₂]Cl₂ The reaction of [(AuCl)₂dppm] (dppm = Ph₂PCH₂PPh₂) with P(Ph)(SiMe₃)₂ in CHCl₃ results in the formation of [Au₁₂(PPh)₂(P₂Ph₂)₂(dppm)₄Cl₂]Cl₂ ( 1 ), the crystal structure of which was determined by single crystal X‐ray analysis (space group P2₁/c, a = 1425.3(3) pm, b = 2803.7(6) pm, c = 2255.0(5) pm, β = 95.00(3)°, V = 8977(3)·10⁶ pm³, Z = 2). The dication in 1 consists of two Au₆P₃ units built by highly distorted Au₃P and Au₂P₂ heterotetrahedra, connected via four bidentate phosphine ligands. Additionally, the compound was characterized by IR‐, UV‐ and NMR spectroscopy. The ³¹P{¹H} NMR spectrum is discussed in detail.     

Preparation of fluorine compounds of groups 13 and 14: a study case for the diagonal relationship of aluminum and germanium

The synthesis of carbaalanes of composition [(AlF)₆(AlNMe₃)₂(CR)₆] containing terminal fluorine atoms is described. The clusters have in common that the central core consists of eight aluminum and six carbon atoms. Six of the eight aluminum atoms are bearing six terminal fluorine atoms. The fluorination of (t-BuNCH₂AlH)₄ results in the formation of the aggregate (t-BuNCH₂AlF)₄. In group 14, the fluorine containing unsaturated compounds LGeF, LGeS(F), LGeSe(F), and LGeNSiMe₃(F) were prepared (LHC(CMeNAr)₂), Ar = 2,6-iPr₂C₆H₃ and Ar = 2,6-Me₂(C₆H₃)).     

用Xα方法对CH4在Ni(Ⅲ)表面吸附解离反应的理论研究

用Ｘ_α方法对ＣＨ_４在Ｎｉ（Ⅲ）表面吸附解离反应的理论研究马晨生,马理,杨忠志（吉林大学理论化学研究所,长春,１３００２３）关键词ＣＨ_４／Ｎｉ（Ⅲ）吸附体系,原子簇模型,ＣＨ_４／Ｍｉ_７,ＭＳ－Ｘ_α－ＳＣＦ方法甲烷在Ｎｉ表面的催化重整反应在工业和国...     

Study of approximate coupled cluster methods for first-order static properties

In this paper, we analyse the algebraic structure of the equations for calculating the first order static properties using several approximate versions of Coupled Cluster (CC) methods. In particular, the non-variational and the variational method using a CC wavefunction corresponding to an appropriately defined perturbed Hamiltonian as well as the simple expectation value expression using a CC stationary state are studied under different approximations. Two different models are proposed: (a) use of maximum overlap orbitals where the pertinent approximations are TT ₂, T ⁽¹⁾ T ₂ ⁽¹⁾, (b) use of Hartree-Fock orbitals and T(T ₁+T ₂), T ⁽¹⁾(T ₁ ⁽¹⁾ +T ₂ ⁽¹⁾ ) approximations. It is analytically shown that in both these models certain approximate versions of the methods under purview yield identical results for first order static properties.NCL Communication No. 3725     

Synthesen und Kristallstrukturen neuer selenidoverbrückter Ruthenium-Clusterverbindungen

Syntheses and Crystal Structures of New Selenido-bridged Ruthenium Clusters The reaction of Se(SiMe₃)₂ with [RuCl₂(PPh₃)₃], or a mixture of [RuCl₂(PPh₃)₃] and alkylphosphines leads to the formation of selenido-bridged ruthenium clusters. In this publication the compounds [Ru₆Se₈(PPh₃)₆] ( 1 ), [Ru₆Se₈(PEt₃)₆] ( 2 ) und[Ru₆Se₈(PⁿPr₃)₆] ( 3 ) are described.The compounds 1-3 contain Ru₆¹⁶⁺ cluster cores with Ru²⁺ and Ru³⁺ centers. The structures of these compounds were elucidated by single crystal X-ray structural analyses.     

Mixed-metal cluster chemistry Part 20. Syntheses, crystal structures and electrochemical studies of W2Ir2(μ-L)(CO)8(η-C5H4Me)2 (L=dppe, dppf)

The 60-electron tetrahedral clusters W₂Ir₂(μ-L)(CO)₈(η⁵-C₅H₄Me)₂ [L=dppe (2), dppf (3)] have been prepared from reaction between W₂Ir₂(CO)₁₀(η⁵-C₅H₄Me)₂ (1) and the corresponding diphosphine in 52 and 66% yields, respectively. A structural study of 2 reveals that three edges of a WIr₂ face are spanned by bridging carbonyls, that the iridium-ligated diphosphine coordinates diaxially and that the tungsten-bound methylcyclopentadienyls coordinate axially and apically with respect to the plane of bridging carbonyls. A structural study of 3 reveals that the dppf ligand bridges an Ir---Ir bond which is also spanned by a bridging carbonyl; tungsten-ligated methylcyclopentadienyl ligands and terminal carbonyls result in electronic asymmetry (17e and 19e iridium atoms) in the electron-precise cluster. Both clusters show two reversible one-electron oxidation processes and an irreversible two-electron reduction; the dppf-containing cluster 3 has a further, irreversible, one-electron oxidation process. UV–vis-NIR spectroelectrochemical studies of the 2→2⁺→2²⁺ progression reveal the appearance of a low-energy transition on oxidation to 2⁺ which persists on further oxidation to 2²⁺.     

Cs3[Tb10(C2)2]Cl21, ein neuer Formel- und Strukturtyp mit isolierten,dimeren Clustern

Cs₃[Tb₁₀(C₂)₂]Cl₂₁, A New Formula and Structure Type with Isolated Dimeric Clusters Cs₃[Tb₁₀(C₂)₂]Cl₂₁ is obtained via the metallothermic reduction of TbCl₃ with caesium in the presence of graphite as black single crystals. The crystal structure (monoclinic, C2/c, Z = 4; a = 2318.72(13); b = 1245.8(9); c = 1502.0(13) pm; β = 98.13(6)°; R = 0.089; R_w = 0.049) contains dimeric clusters that are built from two octahedra connected via one common edge and filled with C₂ units. These isolated [Tb₁₀(C₂)₂] clusters are surrounded by 26 chloride ligands which are then connected via i—a and a—a bridges in a way that voids for Cs⁺ of coordination number 10 are formed.     

Synthese und Kristallstruktur von [(Me3Si)2BiCu(PMe3)3], dem ersten Komplex mit einer Bismut—Kupfer‐Bindung

Synthesis and Crystal Structure of [(Me₃Si)₂BiCu(PMe₃)₃] — the First Complex with a Bismuth—Copper Bond The reaction of CuO^t Bu with PMe₃ and Bi(SiMe₃)₃ in hexane yields the phosphine‐stabilized complex [(Me₃Si)₂Bi‐Cu( PMe₃)₃]. This synthesis gave rise to the first binuclear Bi—Cu compound to be structurally characterized by X‐ray crystallography.     

Complexation and C-H bond activation of 1,5-cyclooctadiene on triosmium carbonyl clusters

Reaction of Os₃(CO)₁₀(NCMe)₂ and 1,5-cyclooctadiene (C₈H₁₂) affords the diene complex Os₃(CO)₁₀(η⁴-C₈H₁₂) (1) with the two alkene moieties coordinated to an equatorial and an axial positions of one osmium atom. Thermolysis of 1 in refluxing n-hexane results in a vinylic C-H bond activation to form (μ-H)Os₃(CO)₉(μ,η⁴-C₈H₁₁) (2) in good isolated yield. The crystal structures of 1 and 2 have been established by an X-ray diffraction study.     

Activation of 1,3,5-trimethyl-1,3,5-triazacyclohexane by Os3(CO)12 to form amidino [(MeN)2CH] cluster complexes

Reaction of 1,3,5-trimethyl-1,3,5-triazacyclohexane [(MeNCH₂)₃] with Os₃(CO)₁₂ in refluxing toluene results in C-H and C-N bond activation of the (MeNCH₂)₃ ligand to afford three amidino cluster complexes (μ-H)Os₃(CO)₁₀[μ,η²-CH(NMe)₂] (1), (μ-H)Os₃(CO)₉[μ₃,η²-CH(NMe)₂] (2), and Os₂(CO)₆[μ,η²-CH(NMe)₂]₂ (3). The controlled experiments show that thermolysis of 1 yields 2, and heating 2 in the presence of (MeNCH₂)₃ ligand produces 3. The molecular structures of 1 and 3 have been determined by an X-ray diffraction study.