Preparation and multinuclear NMR and IR spectroscopic characterization of some complexes of acetyldiphenylphosphine,diphenyl(2-thienyl)phosphine,bis(2-thienyl)phenylphosphine and cyanodiphenylphosphine

The syntheses and multinuclear NMR and IR spectroscopic characterizations of some mononuclear Mo, Pd and Pt complexes of acetyldiphenylphosphine, diphenyl(2-thienyl)phosphine, bis(2-thienyl)phenylphosphine and cyanodiphenylphosphine are presented. The NMR and IR spectra of the Mo carbonyl complexes indicate that the electron-donor ability of the P substituents increases in the order CN < C(O)Me < 2-thienyl < Ph. The reactions of free and coordinated acetyldiphenylphosphine with amines and borohydrides are reported. These reactions do not lead to the desired imino and hydroxymethyl complexes but rather result in PC bond cleavage. Attempts to form dinuclear complexes with bridging 2-thienylphosphine ligands from mononuclear complexes with P-coordinated ligands have not been successful. The products of the reactions result from ligand exchange between the mononuclear precursors and contain only P-coordinated ligands .The structure suggested for a previously reported homodinuclear complex containing a bridging cyanophenylphosphine ligand, (CO)₅Mo(Ph₂PCN)]₂, has been confirmed by multinuclear NMR and IR spectroscopic studies. An attempt to form a heterodinuclear MoPt complex with bridging cyanophosphine ligands has not been successful. The products of this reaction result from ligand exchange between the mononuclear precursors.