TRIANGULO CLUSTER MOLECULES OF COBALT(0) AND NICKEL(0) CONTAINING TRIMETHYLPHOSPHINE AND CARBONYL LIGANDS - SYNTHESES, PROPERTIES, AND X-RAY STRUCTURES

Trinuclear clusters HCo3(mu-CO)a(PMe3)6 (1) and Co2Ni(mu-CO)3(PMe3)6 (2) are syn in high yields from mononuclear precursors by thermal or photochemical activation. X ray structural data of 1 and 2 show molecular cores of regular M3 triangles. 1: trigonal, space group R3cBAR, a = 10.685 (2) angstrom, c = 52.496 (10) angstrom, and Z = 6. 2: trigonal, space group R3cBAR, a = 10.689 (1) angstrom, c = 52.778 (7) angstrom, and Z = 6. While the hydrogen atom of 1 was not located, a positional disorder of metal atoms in 2 gives rise to D3h symmetry Of the M3(CO)3P6 skeleton in both structures. Calculations of the INDO/1 type support proposals of chemical bonding in 1 and 2.