Syntheses and Study of Microwave-Induced Production of Novel Triosmium Carbonyl Complexes with Multiple Bis(diphenylphosphino)methane Ligands

Abstract

New triosmium carbonyl complexes containing multiple bis(diphenylphosphino)methane (dppm) ligands were synthesized via reactions of Os3(CO)12 with excess dppm under microwave irradiation. The new complexes have been characterized by IR, NMR, mass spectrometry, and X-ray crystallography. Three of the four complexes produced, Os3(μ-H)2(CO)6(μ-dppm)[μ3-Ph2PCHP(C6H4)Ph] (2), Os3(CO)6[μ3-Ph2PCH2P(C6H4)Ph]2 (3), and Os3(μ-H)(CO)6[μ3-PhPCH2P(C6H4)Ph][μ3- PhPCH(C6H4)PPh] (4), contain two dppm ligands in a triosmium cluster, while the fourth, Os3(μ-H)(CO)5(dppm)[μ3-PhPCH2P(C6H4)Ph][μ3-PhPCH(C6H4)PPh] (5), contain three dppm ligands, the first of its kind. All of the new complexes contain at least one dppm ligand which underwent C–H and/or C–P bond activation. Complex 2 is a 48e cluster containing two dppm ligands, one intact and one that spans all three osmium sites through a phosphorous atom and the cyclometalated and ortho-metalated carbon atoms. Complex 3 in contrast, is a 46e cluster with two ortho-metalated dppm ligands. Complexes 4 and 5 are 50e clusters with similar metallic framework containing one cyclometalated dppm ligand and one ortho-metalated dppm ligand