Inorganic heterocyclic bis(phosphines): syntheses and structures of a 1,2-bis(diazasilaphosphetidino)ethane and its nickel, molybdenum, and rhodium complexes.

Abstract

Synthesis and characterization of a new, highly electron-rich, chelating bis(phosphine), based on the ethanediyl-linked inorganic heterocycle [Me(2)Si(mu-N(t)Bu)(2)P], are reported. Treatment of nickel chloride with this bis(phosphine) afforded square-planar cis-[[Me(2)Si(mu-N(t)Bu)(2)PCH(2)](2)NiCl(2)], which features isometric nickel-chloride (2.2220(8) A) and nickel-phosphorus (2.1572(8) A) bonds. The ligand reacted with cis-[(piperidine)(2)Mo(CO)(4)] to form colorless cis-[[Me(2)Si(mu-N(t)Bu)(2)PCH(2)](2)Mo(CO)(4)], which has distorted octahedral geometry and long Mo-P bonds (2.5461(18) A). Because of its potential applications in hydrogenation catalysis cis-[[Me(2)Si(mu-N(t)()Bu)(2)PCH(2)](2)Rh(COD)]BF(4) was synthesized. This square-planar, cationic rhodium(I) complex, having symmetrical Rh-P (2.250(2) A) and Rh-C (2.305(6) A) bonds, is structurally related to bis(phospholano)- and bis(phosphetano)rhodium species.