Heterocyclic thiocarboxylato complexes of iron: synthesis, characterization, electrochemistry, and reactions

Abstract

Heterocyclic-thiocarboxylato complexes of iron, CpFe(CO)2SCO-het (het = 2-C4H3O, 2-C4H3S, CH2-2-C4H3S), have been synthesized via the reaction of iron sulfides, (μ-S x )[CpFe(CO)2]2 (x = 3, 4), with heterocyclic acid chlorides het-COCl. Photolytic substitutions of these complexes CpFe(CO)2SCO-het with triphenylphosphine, triethylphosphite, triphenylarsine, and triphenylantimony [ER3 (E = P, R = Ph, OC2H5; E = As, Sb, R = Ph)] exclusively gave the monosubstituted complexes CpFe(CO)(ER3)SCO-het in good yields. The new complexes have been characterized by elemental analysis, UV-Vis, IR, 1H, and 31P NMR spectroscopies and by cyclic voltammetry for a representative family (1, 4a–d). The solid state structures of CpFe(CO)2SCO(2-C4H3S) (2), CpFe(CO)(PPh3)SCO(2-C4H3S) (5a), CpFe(CO)(AsPh3)SCO(2-C4H3S) (5b), and CpFe(CO)(SbPh3)SCO(2-C4H3S) (5c) were determined by X-ray crystal structure analysis.