Synthesis and structures of molybdenum complexes of aryl- and alkylphosphonium triphenylcyclopentadienylide ligands

The hitherto new molybdenum coordination complexes (eta(5)-C5HPh3PEt3)Mo(CO)(3) (I), (eta(5)-C5HPh3PMe2Ph)Mo(CO)(3) (II) and (eta(5)-O5HPh3PMePh2) Mo(CO)(3) (III) has been synthesized and characterized via substitution reactions of triethylphosphonium triphenylcyclopentadienylide (C5HPh3PEt3), dimethylphenylphosphonium triphenylcyclopentadienylide (C5HPh3PMe2Ph) and diphenylmethylphosphonium triphenylcyclopentadienylide (C5HPh3PMePh2) with Mo(CO)(3)(CH3CH)(3) respectively as a stable coordination complexes. The structure of compound was characterized on the basis of H-1 NMR, C-13 NMR, P-31 NMR spectroscopies, elemental analyses, and X-ray crystallography. The structures of the free ligands and their molybdenum complexes I, II, and III were compared with the reported analogous compound (C5H4PMePh2) and its complex (eta(5)-C5H4PMePh2)Mo(CO)(3). The IR spectrum of complex in which values of v(CO) and the M-C-5 (centroid) bond lengths showing strong evidences about the effects the electrondonating ability of ligands towards Mo(CO)(3)(CH3CH)(3) by the multiple phenyl group of cyclopentadienyl ring. The P-C (1) bond distance of II shorter than that of III indicated that the steric effect of PR3 moiety is the dominating factor. (C) 2014 Elsevier B.V. All rights reserved.