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.

Keywords:

• ditolyl dithiophosphate
• molybdenum(IV)
• complexes
• adducts
• spectroscopic studies

Acknowledgements

The authors are thankful to CDRI, Lucknow, for the spectral analysis.

Funding

Ravindra Kumar is grateful to UGC, New Delhi, and Keerti Saraswat is thankful to DST, New Delhi, for financial support.