Formation of new cluster derivatives of triphospholene via ligand substitution and cleavage of P-P bond(s)

Abstract

At room temperature, triphospholene PhPPhPPhPCPh=CPh (L) underwent mono- and di-substitution reactions with [Os3(CO)n(MeCN)] to afford the following derivatives: mono-substituted cluster [Os3(CO)-(2-PhPPhPPhPCPh=UPh)] 1, di-substituted bridged cluster [Os3(CO)10(l,3-PhPPhPPhPCPh=tPh)] 2, and linked cluster [{Os3(CO)}2(l,3-PhPPhPPhPCPh=tPh)] 3 On the other hand, reactions with [Os3(CO)10(MeCN)J gave two isomeric compounds: 2 and [Os3(CO),( 1,3-PhPPhPPhPCPh=UPh)] 4, differing in the orientation of the phenyl group attached to the central unco-ordinated phosphorus atom. At elevated temperatures similar reactions result in cleavage of one P-P bond of the ligand to afford an open cluster [Os3(CO)9(u3-r|3-PhPPhPCPh=CPhPPh)] 5, and cleavage of two P-P bonds to give [Os3(CO)9(u3-PPh)(u3-7i2-PhPCPh=CPhPPh)] 6, arising from the formation of the phosphinidene species. The clusters 1, 2 and 4 can be converted sequentially on heating into 5 and then 6. ©The Royal Society of Chemistry 2000.