Synthesis and characterization of germanium, tin, phosphorus, iron, and rhodium complexes of tris(pentafluorophenyl)corrole, and the utilization of the iron and rhodium corroles as cyclopropanation catalysts

The germanium(IV), tin(IV), and phosphorus(V) complexes of tris(pentafluoro phenyl)corrole were prepared and investigated by electrochemistry for eluci dation of the electrochemical HOMO - LUMO gap of the corrole and the spectr oscopic characteristics of the corrole pi radical cation. This information was found to be highly valuable for assigning the oxidation states in the v arious iron corroles that were prepared. Two iron corroles and the rhodium( I) complex of an N-substituted corrole were fully characterized by X-ray cr ystallography and all the transition metal corroles were examined as cyclop ropanation catalysts. All iron (except the NO-ligated) and rhodium corroles are excellent catalysts for cyclopropanation of styrene, with the latter d isplaying superior selectivities. An investigation of the effect of the oxi dation state of the metal and its ligands leads to the conclusion that for iron corroles the catalytically active form is iron(III), while all accesib le oxidation states of rhodium are active.