CYCLOPENTADIENYLIRON-BIS(PHOSPHINE) COMPLEXES WITH DIMETHYLCHALCOGENIDE LIGANDS - SYNTHESIS, REACTIVITY AND CRYSTAL-STRUCTURE OF [C5H5FE(P(OCH3)3)2(S(CH3)2]PF6

Thermal displacement of coordinated nitriles RCN (R = CH3, C2H5 or n-C3H7) in [C5H5Fe(L2)(NCR)]X complexes (L2 = (P(OCH3)3)2, (P(OC6H5)3)2 or (C6H5)2PC2H4P(C6H5)2 (DPPE)) by E(CH3)2 affords high yields of [C5H5Fe(L2)(E(CH3)2)]X compounds (E = S, Se and Te; X = BF4 or PF6). Spectroscopic data and ligand displacement reactions are presented and discussed together with related observations on [C5H5Fe(CO)2(E(CH3)2)]BF4 compounds. The molecular structure of [C5H5Fe(P(OCH3)3)2(S(CH3)2)]PF6 was determined by a single-crystal X-ray diffraction study: monoclinic, space group P2(1)/n - C2h5 (No. 14) with a = 8.4064(12), b = 11.183(2), c = 50.726(8) angstrom, beta = 90.672(13)-degrees and Z = 8 molecules per unit cell. The coordination sphere of the iron atom is pseudo-tetrahedral with an Fe-S bond distance of 2.238 angstrom.