Photochemistry octacyano complexes

Mo(IV), octacyano complexes, photochemistry, 40 287-289 Mo(V), octacyano complexes, photo-chemistry, 40 283-287... 

The photochemistry of octacyanometallates, and of mixed cyano-dii-mine complexes of the type [W(CN)6(diimine)]2 and [MO(CN)3(bpy)] M = Mo, W, has been reviewed (183). The authors pay particular attention to the role of the counterion in this type of reaction they also call attention to questions which were, at the time of writing, unresolved. A mainly structural and redox review of octacyano-, nitridotetracyano-, and oxotetracyano-metallates (Nb, Ta Mo, W Tc, Re) contains some kinetic and mechanistic information on thermal and photochemical substitution in these complexes, with the main conclusion being that much more needs to be done on such reactions (184). 

It was shown during this period that photolysis of the octacyano d species of Mo(V) and W(V) produces the reduced octacyanometalate(IV) complexes as main photoproducts, and much research has concentrated on the first mechanistic step of action. On the other hand, photolysis of the primary photoproduct, [MfCNlg] of Mo(IV) and W(IV), forming [M02(CN)4] (and the mono- and the diprotonated [M0(0H)(CN)4] and [M0(H20)(CN)4] , depending on the solution pH) as the final product during exhaustive photolysis, was also extensively studied. Photolysis of both these metals d and d systems has also been studied in organic media as an aid in the elucidation of the photolytic mechanisms. The discussion below concentrates on aspects of the research that has been performed with regard to the photochemistry of these M(V) and M(IV) complexes of Mo and W. 

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