摘要：

The thermally stable phosphinocopper(I) hydride cluster H6Cu6(PPh3)6 has been prepared from the reaction of (PPh3CuCl)4 and sodium trimethoxyborohydride in dimethylformamide (DMF). It crystallizes from DMF as H6Cu6(PPh3)6·DMF in the centrosymmetric orthorhombic space group Pbca (D2h15; No. 61) with a = 40.10 ± 0.04, b = 22.46 ± 0.02, c = 21.86 ± 0.02 , and Z = 8. Observed and calculated densities are 1.367 ± 0.005 and 1.368 g cm-3, respectively. A single-crystal X-ray diffraction study based on counter data (sin θmax = 0.65, Cu Kα radiation) has led to the location of all 125 non-hydrogen atoms, the final discrepancy index being RF = 9.2% for 3180 independent nonzero reflections. The crystal consists of discrete molecular units of H6Cu6(PPh3)6 and DMF, mutually separated by normal van der Waals distances. The H6Cu6(PPh3)6 molecule contains a (slightly distorted) octahedral cluster of copper atoms. Two mutually trans faces of this octahedron are enlarged with their copper-copper distances ranging from 2.632 (6) to 2.674 (5) and averaging 2.655 ± 0.017 , while the remaining six copper-copper bond lengths range from 2.494 (6) to 2.595 (5), averaging 2.542 ± 0.044 . Each copper atom is apically bonded to a triphenylphosphine ligand with copper-phosphorus distances varying from 2.217 (7) to 2.262 (7), averaging 2.240 ± 0.017 . Decomposition of the complex with C6H5CO2D yields H2 and HD (but no D2) in varying proportions. An assay of liberated [1H]hydrogen indicates that the cluster is associated with six hydride ligands. Possible sites for these ligands (which were not located from the diffraction study) are discussed.

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