Coordinated acylimido complexes formed by reaction of nitridorhenium and nitridomolybdenum porphyrins with substituted acetic anhydrides

Acylimidorhenium and molybdenum porphyrin complexes were prepared by reacti on of the corresponding nitridometalloporphyrins with substituted acetic an hydrides and their spectral and electrochemical properties were determined. Analysis of the electronic spectral changes with time and initial reactant concentration confirmed that the acylimido formation reaction was first-or der in each reactant and second-order overall. Second-order rate constants for formation of the chloroacetic anhydride complex increased in the order Mn<Cr<Re<Mo. In contrast with the previously reported reactivity of acylimi domanganese and chromium porphyrin complexes, the rhenium and molybdenum de rivatives were unreactive towards triphenylphosphine, strained olefins and silyl ethylene ethers. (C) 1998 John Wiley & Sons, Ltd.