Alkyl Complexes of Iron(IV) Triphenylcorrole

Treatment of the iron(II) corrole complex {K-(thf)(2)}[Fe(TPC)] (TPC = triphenylcorrolate) with alkyl halides produces the tetravalent alkyl species [Fe(R)(TPC)] (R = Me, Et, i-Pr, Cy, t-Bu, 1-Ad). These unique Fe(IV) organometallic compounds are resistant to beta-H elimination and demonstrate stabilities that correlate with the ease of Fe-C homolysis. Thermolysis of the ethyl congener produces the iron(III) corrolate [Fe-III(TPC)] and ethylene. Similar thermolyses in the presence of radical traps such as O-2 and Ph2S2 result in the formation of acetaldehyde and ethyl phenyl thioether, respectively. Treatment of the cyclohexyl derivative with NO leads to the formation of the iron nitrosyl species [Fe(NO)(TPC)]. A kinetic analysis of the alkylation reaction with bromocyclohexane and 1-iodoadamantane is consistent with second-order rate laws, suggesting that addition of the alkyl groups to iron follows either an S(N)2 type pathway or an outer-sphere electron transfer. The reduction of [Fe-III(Et)(TPC)](-), produces the anionic iron(III) species [Fe-III(Et)(TPC)](-), which has been characterized in solution.

Automated summary

This study investigates the reaction of iron corrole complex with alkyl halides, finding that the products have resistance to beta-H elimination and exhibit stability. The thermal decomposition of the products also reveals the formation of ethylene and acetaldehyde, as well as ethyl phenyl thioether when radical traps are present. The reaction of iron with NO results in the formation of iron nitrosyl species. Kinetic analysis of the alkylation reaction suggests that it follows either an S(N)2 type pathway or an outer-sphere electron transfer.