Photosubstitution reactions in potassium octacyanomolybdate(IV) and octacyanotungstate(IV) in the presence of 1,10-phenanthroline and 2,2 [formula omitted]bipyridyl

Abstract

Substitution reactions take place following the photonic excitation of aqueous K 4M(CN) 8 (where M = Mo or W) in the presence of 1,10-phenanthroline and 2,2 - ́ bipyridyl. Changes in absorbance with time show that the overall reaction is dependent on photochemical activation of potassium octacyanomolybdate(IV) and -tungstate(IV). The species [K 2Mo(CN) 4(OH) 2(phen)], [K 2W(CN) 4(OH) 2(phen)], [K 2Mo(CN) 4(OH) 2(bipy)] and [K 2W(CN) 4(OH) 2(bipy)] exist in solution. The final photosubstitution products [Mo(OH) 3(CN)(phen) 2] · 2H 2O], [Mo(OH) 3(CN)(bipy) 2] · 3H 2O, [W(OH) 3(CN)(phen) 2] · 2H 2O and [W(OH) 3(CN)(bipy) 2] · H 2O have been isolated in the solid state. Their IR spectra have been discussed. The quantum yield of the photosubstitution reactions has been determined and its variation with change of concentration of the complex as well as the H + ion concentration has been studied.