Synthesis and molecular geometry of hexameric triphenylphosphinocopper(I) hydride and the crystal structure of H6Cu6(PPh3)6. HCONMe2 [hexameric triphenylphosphino copper(I) hydride dimethylformamide]

Abstract

The thermally stable phosphinocopper(I) hydride cluster H8Cu8(PPh3)8 has been prepared from the reaction of (PPh3CuCl)4 and sodium trimethoxyborohydride in dimethylformamide (DMF). It crystallizes from DMF as H8Cue(PPh3)8• DMF in the centrosymmetric orthorhombic space group Pbca (Zk/,15; No. 61) with a = 40.10 ± 0.04, b = 22.46 ± 0.02, c ~21.86 ± 0.02 Á, 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 9max = 0.65, Cu Ka radiation) has led to the location of all 125 nonhydrogen atoms, the final discrepancy index being Rf = 9.2% for 3180 independent nonzero reflections. The crystal consists of discrete molecular units of H8Cu8(PPh3)8 and DMF, mutually separated by normal van der Waals distances. The H6Cue(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 Á, while the remaining six copper-copper bond lengths range from 2.494 (6) to 2.595 (5), averaging 2.542 ± 0.044 Á. 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 A. Decomposition of the complex with CeHsCChD yields Ha and HD (but no D2) in varying proportions. An assay of liberated [ ]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.

Expanded redox accessibility via ligand substitution in an octahedral Fe6Br6 cluster

“…Finally, the cluster features an Fe-Br distance of 2.445(2) Å . We note that while a number of octahedral M 6 X 6 (M = Cu, 7 Zr, 8 Nb, 9 Mo, 10 Ta, 11 W, 12 Re 13 ) clusters have been previously isolated, to the best of our knowledge, compound 1 represents the first example of a structurally characterized octahedral M 6 X 6 cluster comprised of a Group VIII metal core not supported by an interstitial oxygen atom. 14,15 The variable-temperature dc magnetic susceptibility data for 1, collected on a powder sample under an applied field of 1 T, is depicted in Fig.…”

Copper‐Catalyzed Highly Regio‐ and Stereoselective Directed Hydroboration of Unsymmetrical Internal Alkynes: Controlling Regioselectivity by Choice of Catalytic Species

“…It is known that {CuH} species are liable to aggregate, which considerably decreases their reactivity 10b. 27 Furthermore, the bulky Xan ligand derivatives may accelerate the insertion of CuH into an alkyne; a recent paper reported that the bulky bidentate phosphane ligand accelerates the insertion of CuH into a styrene 28…”

Synthesis and Crystal Structure of the Copper(I) Chloride Complex with 4,5(4-Pyridylethylene)dithio-1,3-dithiol-2-thione and Triphenylphosphine

“…Many complexes of copper(I) halides with triarylphosphines [14][15][16][17] and heterocyclic thiones [18] are known. Ligands containing nitrogen and sulfur usually behave as monodentate ligands and bind to the copper atom through the S atom to form both monomeric and dimeric complexes.…”