The photolysis of bis(acetonitrile) tetrachlorotungsten in acetonitrile
When WCl6 is dissolved in CH3CN it is reduced to WCl4(CH3CN)2 in a first-order process with a half-life of 52 s. Irradiation of the WCl4(CH3CN)2 solution at 365 nm yields WO2Cl2(CH3CN)2. Further irradiation of this solution with access to air yields a blue, partially reduced form of WO3 · 2H2O, which eventually precipitates.
Ryan J. Fante and Patrick E. Hoggard, “The photolysis of bis(acetonitrile) tetrachlorotungsten in acetonitrile”, Transition Metal Chem. 33, 825-828 (2008).