Abstract :
The dipalladium complexes, [PdCl(μ-MeN{P(OR)2}2)]2 (R = CH2CF3, 1a; Ph, 1b) react with [Mo2(η5-C5H5)2(CO)6] in boiling benzene to afford the molybdenum–palladium heterometallic complexes, [(η5-C5H5)(CO)Mo(μ-MeN{P(OR)2}2)2PdCl] (R = CH2CF3, 3a; Ph, 3b), [(η5-C5H5)Mo(μ3-CO)2(μ-MeN{P(OR)2}2)2Pd2Cl], (R = CH2CF3, 5a; Ph, 5b), [(η5-C5H5)(Cl)Mo(μ2-CO)(μ2-Cl)(μ-MeN{P(OR)2}2)PdCl], (R = CH2CF3, 6a; Ph, 6b) and also the mononuclear complex [Mo(CO)Cl(η5-C5H5)(κ2-MeN{P(OR)2}2)], (R = Ph, 4b). These complexes have been separated by column chromatography and are characterised by elemental analysis, IR, 1H, 31P{1H} NMR data. The structures of 1a, 3a, 4b, 5b and 6a have been confirmed by single crystal X-ray diffraction. The CO ligands in 5b and 6a adopt a semi-bridging mode of bonding; the Mo–CO distances (1.95–1.97 Å) are shorter than the Pd–CO distances (2.40–2.48 Å). The Pd–Mo distances fall in the range, 2.63–2.86 Å. The reaction of [Mo2(η5-C5H5)2(CO)6] with MeN{P(OPh)2}2 in toluene gives [Mo2(CO)4(η5-C5H5)2(κ1-MeN{P(OPh)2}2)2] (2) in which the diphosphazane acts as a monodentate ligand.
