2,2′-Bipyridyl derivatives of molybdenum-(IV), -(V), and -(VI) and tungsten-(IV), -(V), and -(VI)

Abstract

Reaction of the compounds M(CO)₄Bipy (Bipy = 2,2′-bipyridyl; M = Mo and W) with excess of chlorine and bromine leads to derivatives of the metals in oxidation states 4, 5, and 6. Reaction in pure dichloromethane yields the derivatives MBipyX₄, while similar reactions in the presence of small amounts of ethanol lead to the oxo-trihalides MoOBipyX₃ and WOBipyCl₃. Reaction of bromine with the compound Mo(CO)₄Bipy in a 1:1 ethanol–dichloro-methane yields MoO₂BipyBr₂ and the corresponding dichloride can be prepared by a metathetical reaction in boiling acetone. The compounds WO₂BipyX₂ can be prepared readily in pure ethanol.