Lewis-Base Adducts of Group 11 Metal(I) Compounds. LIX. Crystal Structure Determinations of Tetrakis(trimethylphosphine)copper(I) Halides and Tetrakis(triphenylphosphine)-copper(I) and -silver(I) Hexafluorophosphates

Abstract

The crystal structures of [Cu(Pme₃)₄]X (X = Cl , Br, I) and of [M(PPh₃)₄] [PF6] (M = Cu, Ag) have been determined by single-crystal X-ray diffraction methods at 295 K. The former compounds contain nearly tetrahedral [Cu(PMe₃)₄]⁺ ions on sites of m symmetry with mean Cu-P bond lengths of 2.270, 2.271 and 2.278 Ǻ for X = Cl , Br and I respectively. The latter compounds contain [M(PPh₃)₄]⁺ ions on sites of 3 symmetry. In the M =Ag complex the coordination environment is close to tetrahedral, but in the M =Cu complex the length of the axial Cu-P bond [2.465(2)Ǻ] is significantly shorter than that of the off-axis bonds [2.566(2)Ǻ]. Possible reasons for this are discussed.