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Nitrile ylides of fluorenylidene (RR'C--N+C-R": R" = CH3 or C6H5; R, R' = CI2H8) serve as carbene equivalents in reactions with (salen)metal complexes (salen = AUV'-ethylenebis(salicylideneaminato)) of first-row transition metals in acetonitrile or benzonitrile solvents. The microscopic rate constants for these reactions were obtained directly by flash photolysis experiments and were found to depend upon the nature, oxidation state, and ligation of the metal. Oxo(salen)chromium(V) triflate reacts with a rate constant close to the diffusional limit to form (salen)chromium(III) triflate and fluorenone. The reactivities of (salen)metal(Ill) cations are lower and decrease in the order V > Cr > Mn > Fe. The reactions of the ylides with metal(III) cations apparently form metallocarbenes or related species, and products resulting from carbene insertion into a metal-ligand bond (as identified for M = Cr) ultimately are obtained.

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