MOLECULAR-STRUCTURE, BONDING, AND REACTIONS OF MO(ETA-5-C5H5)2 DERIVATIVES CONTAINING PHOSPHORUS LIGANDS - CRYSTAL-STRUCTURES OF [MO(ETA-5-C5H5)2H(PPH3)]I . 1/2H2O AND [MO(ETA-5-C5H5)2(CH3)(PPH3)][PF6]

The oxidative addition reactions of [Mo(η5-C5H5)2(PPh3)], prepared by deprotonation of [Mo(η5-C5H5)2H(PPh3)][PF6] with HCl, CH3I, (CH3)3SiCl and (C2H5)2S2 are described. Two of the complexes obtained have been characterized by single crystal X-ray diffraction studies, viz: [Mo(η2-C5H5)2H(PPh3)]I.1/2H2O (1a) and [Mo(η5-C5H5)2(CH3)(PPh3)][PF6] (3). In complex 1a, the MoH and MoP bond lengths are 1.74(8) and 2.501(4) Å, and the HMoP angle is 77(2)°, while in complex 3 the MoC and MoP bond lengths are 2.269(7) and 2.526(4) Å and the CMoP angle is 84.1(2)°. Molecular orbital and steric energy calculations have been carried out for some model complexes in order to throw light on their geometrical preferences and to evaluate the influence of a bulky ligand in association with a small hydride on the overall geometry of the molecule. © 1990.