The crystal and molecular structure of the coordinatively unsaturated Ni(0) species Ni(PPh3)3

Article abstract of DOI:10.1139/v90-096

The disproportionation of the complex (Et₂N)₃Ti(μ-PCy₂)Ni(PPh₃) affords the coordinatively unsaturated species Ni(PPh₃)₃, 1. This compound crystallizes in the triclinic space group PI, with a = 18.483(4) ?, b = 16.203(3) ?, c = 17.783(4) ?, a = 105.85(2)°, β = 117.33(3)°, γ = 92.33(3)°, Z = 4, and V = 4464(2) ?³. Full-matrix least-squares refinement of 1042 variables using 6484 data (F₀² > 3crF₀²) gave R = 0.0441 and R_w = 0.0438. The two crystallographically independent molecules are essentially identical, each exhibiting a trigonal planar coordination sphere at Ni. The most interesting feature of the structure is the close approach (2.744-3.094 ?) of three ortho hydrogens of the PPh₃ groups to the Ni centres. The implications of the structural data regarding ortho metallation and the known instability of 1 are discussed.