Perchlorate and difluorophosphate coordination derivatives of manganese carbonyl

Abstract

The complexes Mn(CO)₅(OClO₃) and Mn(CO)₃L₂(OClO₃) (L = PPh₃, P(OPh)₃; L2 = bpy*) are formed by abstraction reactions with AgClO₄ from the corresponding bromo complexes in dichloromethane. The perchlorato complexes have been characterized by i.r. and mass spectroscopy. They undergo facile substitution reactions in which the perchlorato group is replaced by halide ions (X^- = Cl, Br, I), phosphines [PR₃ (R = Ph, p- tolyl, m-tolyl), dpe, dpm]* or solvent molecules (MeCN, PhCN, MeOH, Me₂CO, py*). Reaction with fluoride ion yields Mn(CO)₃F₃ plus other decomposition products. When Mn(CO)₅X and Mn(CO)₃L₂X (X = Br) are made to react with AgPF₆ in dichloromethane, hydrolysis of the PF₆^- ion occurs to yield the corresponding difluorophosphato complexes (X = PO₂F₂^-), which have been characterized by i.r., ¹⁹F N.M.R. and mass spectroscopy. They are reasonably stable at low temperatures, but decompose at room temperature. The difluorophosphato group is more inert than perchlorato with the rate of substitution decreasing in the order CO ≈ PPh₃ > bpy > P(OPh)₃.