TRINUCLEAR OSMIUM CLUSTERS CONTAINING AMINOPHOSPHINE AND PHOSPHINOAMIDO LIGANDS, SYNTHESIS AND MOLECULAR STRUCTURE OF Os3(CO)11(PPh2NHPh) AND HOs3(CO)8(PPh2NHPh)(PPh2NPh)

Article abstract of DOI:10.1016/0022-328X(87)85083-0

The pyrolysis of the heterocycle B2H4N4P2Ph8 in the presence of Os3(CO)12 yields the osmium clusters Os3(CO)11(PPh2NHPh)(PPh2NPh) (1), Os3(CO)10(PPh2NHPh)2 (2) and HOs3(CO)8(PPh2NHPh)(PPh2NPh) (3) which contain aminophosphine and phosphinoamido fragments as ligands.The molecular structures of 1 and 3 have been determined by single-crystal X-ray diffraction studies.Crystals of 1 are monoclinic, space group P2₁/c with Z=4 in a unit cell of dimensions a 21.881(12), b 8.887(6), c 16.348(9) Angstroem, β 98.91(2) deg.Crystals of 3 are rhombohedral, space group R3 with Z=6 in a unit cell of dimensions a 21.143(9) Angstroem, α 106.89(3) deg.Both structures were solved by direct and Fourier methods and refined by full-matrix least-squares to R=0.0456 for 2288 observed reflections in 1 and to R=0.0490 for 4063 observed reflections in 3.The structure of 1 can be regarded as derived from that of Os3(CO)12 by replacing one carbonyl by an aminophosphine ligand (bound through the P atom).In the structure of 3, one hydride bridges one Os-Os edge of the triangular metal cluster and a phosphinoamido ligand interacts with all three Os atoms (with two through the N atom and with the third through the P atom); a terminal aminophosphine ligand is also present, as in 1.