Synthesis, characterisation and thermal behaviour of cyano(oxine)-molybdenum(IV) and -tungsten(IV)

Abstract

A new class of adduct compounds of octacyano-molybdate(IV) and -tungstate(IV) complexes with oxine, of the type K 4[M(CN) 8]·8(C 9H 70N)·5H 20 (where M = Mo or W) was synthesised. FTIR spectra show bands in the range 2000–2200 cm −1 and around 1120 cm −1 indicating the presence of the cyano group, -CN, as well as oxine through the -N=0 mode. The d spacing from the X-ray diffraction patterns were determined and compared with those of known compounds. Thermogravimetric analysis indicated the removal of uncoordinated water up to 150°C. Oxine and cyano molecules were removed stage by stage at higher temperatures. The final products from thermal treatment are oxides of polymeric nature. The kinetic parameters n and E a were determined by means of TGA and DTG thermograms.