Photo-catalysed synthesis, characterization and thermal behaviour of the adducts of 8-hydroxyquinoline with the photoproducts of octacyanomolybdate(IV) and -tungstate(IV) with 1,2,3-benzotriazole and triethylenetetramine

423-427The 8-hydroxyquinoline adducts and complexes of molybdenum(IV) and tungsten(IV) of the type K2[Mo(CN)(OH)(O2)(C6H5N3)(C9H7ON)]·2C9H7ON·H2O [I], K2[W(O2)(O)(C9H7ON)3] [II] and K3[W(CN)2(O2)(OH)(C9H7ON)·2C9H7ON·2H2O [III) have been synthesised starting from the octacyanomolybdate(IV) or -tungstate(IV) by exposure to UV light in the ligand field band in the presence of 1,2,3-benzotriazole or triethylenetetramine. The IR spectra of the complexes I and III show a strong band of nC=Nstretching in the range 2100-2150 cm-1. The oxine group n(C-O)in the complexes I, II and III is represented by a strong peak in the range 1100-1140 cm- 1. The lower region of the IR spectra shows M=O stretching while the higher range the n(N- H) and n(OH) modes. The thermal decomposition of the complexes starts from 160°C with the removal of uncoordinated water and continues up to 800°C.Oxine and cyano groups are removed stage by stage. The final products from the thermal treatment are oxides of the type K2O· MO3 (where M=Mo, W). The kinetic parameters, viz., order of reaction (n) and activation energy (Ea) have been determined using TG curves