Synthesis and Spectroscopic Characterization of Mononuclear Oxomolybdenum(IV)O,O′-Ditolyl Dithiophosphate Complexes and Their Adducts With 2,2′-Bipyridyl and 1,10-Phenanthroline

Abstract

A series of mononuclear oxomolybdenum(IV) O,O′-ditolyldithiophosphate complexes, of the type MoO[S2P(OR)2]2 (R = o-,m-,p-C6H4Me), were synthesized by refluxing of the reaction mixture containing triphenylphosphine and binuclear oxomolybdenum(V)O,O′-ditolyldithiophosphate, Mo2O3[S2P(OR)2]4 (R = o-,m-,p-C6H4Me), in equimolar ratio in dichloromethane. The desired pink colored Mo(IV) complexes were separated out by dissolving in cold n-hexane. The equimolar adducts of mononuclear oxomolybdenum(IV) O,O′-ditolyldithiophosphates with heterocyclic amines, MoO[S2P(OR)2]2.L (R = o-,m-,p-C6H4Me; L = 2,2′-bipyridyl and 1,10-phenanthroline), have been prepared by reacting the corresponding oxomolybdenum(IV) complexes with an excess of 2,2′-bipyridyl and 1,10-phenanthroline in a 1,1 molar ratio. The complexes have been characterized by elemental analysis, IR, 1H. and 31P NMR spectroscopy. Based on these, a square pyramidal structure incorporating bidentate dithiophosphate moieties is suggested and a six-coordinated distorted octahedral structure for the entire base adducts complexes. It appears that oxomolybdenum(IV) is preferentially stabilized by sulfur donors.