Synthesis of Group 6 metal carbonyl complexes with iminophosphine ligands: crystal structure of [Mo(CO)4(o-Ph2PC6H4–CHNMe)]

The synthesis of new molybdenum and tungsten carbonyl complexes with the mixed donor bidentate ligands o-Ph2PC6H4–CHNR is described. Two series of complexes [M(CO)4(o-Ph2PC6H4–CHNR)] (M=Mo; R=Me (1a), Et (2a), iPr (3a), tBu (4a), NH–Me (5a). M=W; R=Me (1b), Et (2b), iPr (3b), tBu (4b), NH–Me (5b)) have been prepared by direct reaction of the ligands with the corresponding precursors cis-[M(CO)4(pip)2] (M=Mo or W; pip=piperidine NHC5H10). The new complexes were characterized by partial elemental analyses and spectroscopic methods (IR, 1H, 13C and 31P NMR). The molecular structure of compound 1a (monoclinic, P21/n) was determined by a single-crystal diffraction study.