Reactions of Na[Mo(CO)3(η-C5H5)] towards CoCl(PPh3)3 and CoCl(P(OMe)3)5: X-ray crystal structures of [MoCo(CO)6(PPh3)(η5-C5H 5)] and [Mo(CO)3(P(OMe)3)(η5-C5H 5)]2

Article abstract of DOI:10.1016/0277-5387(95)00546-3

Reaction of Na[Mo(CO)₃(η⁵-C₅H₅)] with CoCl(PPh₃)₃ in tetrahydrofuran under 1 atm of CO yielded two heterobimetallic compounds : [MoCo(CO)₅(PPh₃)₂(η⁵-C ₅H₅)] (1a) and [MoCo(CO)₆(PPh₃)(η⁵-C₅H ₅)] (1b). Both compounds were characterized by mass, IR, ¹H, ¹³C and ³¹P NMR spectra. The X-ray crystal structure of 1b was determined. The cobalt centre of 1b has acquired three carbonyl groups and released two triphenylphosphine ligands during the reaction. The only PPh₃ which remained on the cobalt centre was in the axial position of the trigonal bipyramidal structure, thus avoiding steric interaction with ligands from the molybdenum fragment. The molybdenum centre is in a 'four-legged piano stool' configuration. From the reaction of Na[Mo(CO)₃(η⁵;-C₅H₅)] and CoCl(P(OMe)₃)₅ in tetrahydrofuran, an unexpected bimetallic compound [Mo(CO)₂(P(OMe)₃)(η5-C₅H₅)] ₂ (6) was obtained which was characterized by mass, IR, ¹H, ¹³C and ³¹P NMR spectra. The molecular structure of 6 was also determined by X-ray diffraction. The centrosymmetric complex is a typical four-legged piano-stool dimer. The M - M bond length (3.239 A) is longer than the sum of the metal radii. Copyright