ELECTROCHEMICAL INVESTIGATION OF MOLYBDENUM(3)-CHLORO COMPLEXES WITH PYRIDINE 2,2'-BIPYRIDINE AND 1,10-PHENANTHROLINE IN ACETONITRILE

A series of molybdenum(III)-chloro complexes with pyridine, 2,2′-bipyridine, and 1,10-phenanthroline were prepared and their electrochemistry in acetonitrile was studied. The compounds investigated included MoCl3(py)3, MoCl3(py)bipy, MoCl3(py)phen, (C2H5)4N[MoCl4(py)2], (C2H5)4N[MoCl4bipy], (C2H5)4N[MoCl4phen], [MoCl2(bipy)2][MoCl4bipy], [MoCl2(phen)2][MoCl4phen], and [MoCl2(phen)2]Cl. Current-voltage curves of acetonitrile solutions of all of the compounds exhibited at least one reversible one-electron reduction step. In addition, a second reversible one-electron reduction step was observed for the compounds containing the MoCl2(phen)2+ and MoCl2(bipy)2+ cations. These steps are attributed to the reduction of the metal. At potentials more negative than those required for metal reduction, cathodic waves were found which, on the basis of the electrochemical evidence, have been ascribed to reduction of the ligands. Compounds containing MoCl4-amine anions gave reversible one-electron oxidation steps involving the conversion of the metal in the anion to the tetrapositive state. Anodic steps, at more positive potentials than for the MoCl4-amine anions, occur for the other molybdenum complex species. Of the complexes studied, (C2H5)4N[MoCl4(py)2], [MoCl2(phen)2][MoCl4phen], and [MoCl2(phen)2]Cl were prepared for the first time. © 1969, American Chemical Society. All rights reserved.