Sensitized Photolysis of Octacyanomolybdate(IV)

Abstract

The photochemical loss of cyanide from Mo(CN)84− is shown to be sensitized by common organic triplet donors naphthalene, phenanthrene, anthraquinone, and benzophenone, but not by biacetyl. This suggests that the reactive state may be 3B1, not the lower lying 3A2. The quantum yields for sensitized photolysis (near 0.25) are larger than for the direct reaction (near 0.15). This is unlike the behavior of Co(CN)63− where the similarity of the two yields leads to the conclusion that higher excited states are efficiently converted to "the lowest triplet".Naphthalene irradiated at 286 nm leads to a quantum yield of 0.4 which is, perhaps, associated with a new process involving sensitized production of a solvated electron.Thermal solvolysis rates in several media are also reported. The medium dependence of solvolysis is small.