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 0 -ditolyldithiophosphate complexes, of the type MoO[S 2 P(OR) 2 ] 2 (R D o-,m-,p-C 6 H 4 Me), were synthesized by refluxing of the reaction mixture containing triphenylphosphine and binuclear oxomolybdenum(V)O, O 0 -ditolyldithiophosphate, Mo 2 O 3 [S 2 P(OR) 2 ] 4 (R D o-,m-,p-C 6 H 4 Me), 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 0 -ditolyldithiophosphates with heterocyclic amines, MoO[S 2 P(OR) 2 ] 2. L (R D o-,m-,p-C 6 H 4 Me; L D 2,2 0 -bipyridyl and 1,10-phenanthroline), have been prepared by reacting the corresponding oxomolybdenum(IV) complexes with an excess of 2,2 0 -bipyridyl and 1,10-phenanthroline in a 1,1 molar ratio. The complexes have been characterized by elemental analysis, IR, 1 H. and 31 P 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.