Synthesis and crystal structure of novel mononuclear Mo(IV) and Mo(III) complexes containing bis(3,5-dimethylpyrazol-1-yl)acetate anion as ligand

Reaction of bis(3,5-dimethylpyrazol-1-yl)acetic acid (Hbdmpza) with [MoCl4(Ac)2], in acetonitrile (Ac) at room temperature results in obtaining [Mo(IV)Cl3(bdmpza)]∙Ac (1) (Ac = acetonitrile). The treatment of 1 in pyridine (py) gives pyH[Mo(III)Cl3(bdmpza)]∙2py (2) (py = pyridine. The complexes were characterized by X-ray structure analysis, UV-visible and IR spectroscopy. The coordination spheres in the molecule [MoCl3(bdmpza)] and in the anion [MoCl3(bdmpza)]– are the same. Both species exhibit a six-coordinate distorted octahedral geometry. They differ only in the oxidation state of the central molybdenum ion.