Substituted Group VI metal carbonyl complexes with the ligands trimethylphosphine, dimethylphenylphosphine, dimethylphenylarsine, and dimethyl phenylphosphonite
Series of substituted metal carbonyls of the types [M(CO)6–xLx][M = Cr, Mo, or W; x= 1, 2, or 3; L = PMe3, PMe2Ph, P(OMe)2Ph, or AsMe2Ph] are described. I.r. and n.m.r. spectral data and dipole moment results are given and discussed. The methyl resonance patterns of the tertiary phosphine or phosphonite complexes are not particularly useful in determining stereochemistry since they are of the type corresponding to intermediate phosphorus–phosphorus coupling.