Reactions of metal carbonyls. Part III. Steric and stereochemical limitations of higher substitution of manganese carbonyl bromide
Abstract
The reaction of [Mn(CO)5Br] with the ligands, L [L = P(OMe)3, P(OEt)3, P(OMe)2Ph, PMe3, PMe2Ph, and AsMe2Ph] have given fac- and trans-[Mn(CO)3L2Br] and terminated with mer-[Mn(CO)2L3Br]. The complex trans-[Mn(CO)2{P(OMe)3}3Br], prepared by hydrazine reduction of trans-[Mn(CO)2{P(OMe)3}3Br]PF6, further reacts with P(OMe)3 to give the tetra substituted compound trans-[Mn(CO){P(OMe)3}4Br]. Factors influencing the substitution reactions of [Mn(CO)5Br] with monodentate tertiary phosphorus and arsenic ligands are discussed in terms of incoming ligand size and the stereochemistry of the manganese carbonyl complexes. The i.r. and 1H n.m.r. spectra of these complexes are discussed.