OXIDATIVE ADDITION VS LIGAND-EXCHANGE - FE(II)-MIXED-PHENYLCHALCOGENOLATE COMPLEXES FAC-[PPN][FE(CO)3(TEPH)N(SEPH)3-N] (N=1, 2)

Diphenyldichalcogenides (PhE)2 (E = Te, Se) react with Fe(0)-phenylchalcogenolate [PPN] [PhEFe(CO)4] to yield the products of oxidative addition, Fe(Il)-mixed-phenylchalcogenolate fac-[PPN][Fe(CO)3(TePh)n(SePh)3-n] (n = 1, 2). Reactions of [PPN][REFe(CO)4] (E=Se, R=Me; E=S, R=Et) and diphenyldichalcogenides yielded ligand-exchange products [PPN][PhEFe(CO)4] (E=Te, Se, S). The compounds [Fe(CO)3(TePh)(SePh)2]- (1) and [Fe(CO)3(TePh)2(SePh)]- (2) crystallize in the isomorphous monoclinic space group C2/c, with a = 32.035(8), b = 11.708(6), c = 28.909(6) angstrom, Z = 8, R = 0.048, and R(w) = 0.044 (1); with a = 32.089(5), b = 11.745(2), c = 28.990(8) angstrom, Z = 8, R = 0.048, and R(w) = 0.048 (2). The complexes 1 and 2 crystallize as discrete cations of PPN+ and anions of [Fe(CO)3(TePh)n(SePh)3-n]- (n = 1, 2), and one half solvent molecule THF. The geometry around Fe(II) is a distorted octahedron with three carbonyl groups and three phenlylchalcogenolate ligands occupying facial positions.