Preparation and characterization of (1–2-η-ethylene)bis[1,2-bis(diphenylphosphino)ethane]molybdenum(0) and bis[1,2-bis(diphenylphosphino)ethane]hydrido(pentane-2,4-dionato)molybdenum(II)

Abstract

Treatment of [Mo(acac)₃](acac = pentane-2,4-dionato) and 1,2-bis(diphenylphosphino)ethane (dppe) in toluene with AlEt₃ under an argon atmosphere yields the η-ethylene complex [Mo(C₂H₄)(dppe)₂], (I), and [MoH(acac)(dppe)₂], (II). The relative yields of complexes (I) and (II) depends on the amount of AlEt₃ used. Characterization of these complexes has been achieved chemically and spectroscopically. Complex (II) is also produced by the reaction of (I) with pentane-2,4-dione. Reversible interconversion of complex (I) and trans-[Mo(N₂)₂(dppe)₂] has been observed. Reaction of complex (I) with tetracyanoethylene (tce) yields an η-tce complex. Complex (II) has been found to initiate polymerization of acrylonitrile.