Synthesis and characterization of mononuclear bis(para-substituted phenolato)oxomolybdenum(V) complexes: dependence of the molecular properties upon remote substituent effects

Bis(para-substituted phenolato)oxomolybdenum(V) complexes with the general formula LMoO(OC 6 H 4 X) 2 , where L=hydrotris(3,5-dimethyl-1-pyrazolyl)borate and X=Me, Et, OMe, OEt, OH, F, Cl, Br, I, and CN, have been prepared and characterized by elemental analyses, mass spectrometry, and IR, EPR, and UV-vis-near-IR spectrospy. The energies of both the ligand-field and the lowest-energy charge-transfer bands depend upon the σ p values of the para substituents (X) on the phenolato ligands