Metal carbonyl chemistry. Part VII. The reaction of ligands with phenylpentacarbonylmanganese

Abstract

The preparation of phenyl- and benzoyl-manganese carbonyl complexes from the reactions of the ligands 1-ethyl-4-phospha-3,5,8-trioxabicyclo[2,2,2]octane, P(OCH₂)₃CEt, triphenylphosphine, or triphenyl phosphite with phenylpentacarbonylmanganese are described. The phosphite ligands lead to the formation of mono-, di-, and tri-substituted compounds of the type PhCOMn(CO)₄L, PhMn(CO)₄L, PhCOMn(CO)₃L₂, PhMn(CO)₃L₂, [where L = P(OPh)₃ or P(OCH₂)₃CEt], and PhCOMn(CO)₂[P(OCH₂)₃CEt]₃ depending on the reaction conditions employed. The reaction with triphenylphosphine gives cis-PhMn(CO)₄PPh₃, although some evidence was obtained for the intermediate formation of the unstable compound PhCOMn(CO)₄PPh₃. The stereochemistry of these compounds is discussed on the basis of their dipole moments, and infrared and ¹H n.m.r. spectroscopic measurements.