LIGAND-FIELD PHOTOCHEMISTRY OF MIXED-LIGAND CYANOCHROMATES - COMPARATIVE-STUDY OF [CR(CN)(5)(OH)](3-) AND [CR(CN)(4)(N-3)(OH)](3-)

The novel mixed-ligand cyanochromate, [Cr(CN)(4)(N-3)(OH)](3-), has be en synthesized and its LF-photochemistry has been studied and compared with that of the better known pentacyanohydroxochromate (III). In bot h the cases the reaction consists in the photosubstitution of one CN- ligand followed by fast thermal CN- release leading to the formation o f one relatively stable product. The chemical and spectral analysis of the products showed their formulation as triacido-complexes, [Cr(CN)( 3)(OH)(n)(H2O)(3-n)](n-) and [Cr(CN)(2)(N-3)(OH)(n)(H2O)(3-n)](n-), re spectively. The results contribute to the discussion on preferential l igand photosolvation.