Abstract: Through the reaction of (μ-RS)(μ-R'S)Fe₂(CO)₆ Awith PPh₃ in boiling benzene or toluene for several hours, four mono PPh₃-substituted complexes (μ-RS)(μ-R'S)Fe₂(CO)₅PPh₃ Band three bis-PPh₃-substituted complexes (μ-RS)(μ-R'S)(Fe₂(CO)₄(PPh₃)₂ Cwere synthesized, respectively; similarly, the reaction of Awith AsPh₃ in boiling toluene afforded two bis-AsPh₃-substi-tuted derivatives (μ-RS)(μ-R'S)Fe₂(CO)₄(AsPh₃)₂ D.The relative reactivity of PPh₃ and AsPh₃ towards C≡Osubstitution and some influences of the two ligands on IRand ¹H NMRspectra of the complexes were pointed out, as well as the structural characterization of these new complexes were determined by elemental analysis, IRand ¹H NMR.

Key words: Ph₃P-substituted complexes, AsPh₃-substituted complexes, Bis-(alkylthio)hexacarbonyldi-iron