ORGANOTRANSITION METAL SUBSTITUTED PRIMARY PHOSPHINES - OSMIUM PHOSPHIDO (PH2) COMPLEXES

Stable osmium phosphido complexes, Os(η2-chelate)(PH2)(CO)(PPh3)2 , (chelate = acetate, N,N-dimethyldithiocarbamate, acetylacetonate, or nitrite) have been prepared by treating [OsCl(PH3)(NCCH3)(CO)(PPh3)2 ]ClO4 with sodium acetate, sodium N,N-dimethyldithiocarbamate, acetylacetone/DBU, and sodium nitrite/DBU respectively. These and the related phosphido complexes OsX(PH2)(CO)2(PPh3)2, (X = H, Cl, OAc) undergo reactions with the electrophiles H+, R+, Fe(CO)4, AuI, S8, and Se and the products have all been characterised. An X-ray diffraction study has established the structure of Os(η2-OAc)(PH2AuI)(CO)(PPh3)2 · (CH2Cl2)2. The preparation of complexes with the unusual methylphosphinite (PH2OMe) ligand, M(PH2OMe)(CO)2(PPh3)2 (M = Ru, Os) and [MH(PH2OMe)- (CO)2(PPh3)2]ClO4 (M = Ru, Os) and the methylthiophosphinite (PH2SMe) ligand, [OsX(PH2SMe)(CO)2(PPh3)2]ClO 4, (X = Cl, H) are also described. © 1990.