SYNTHESIS, CHARACTERIZATION AND THERMAL-BEHAVIOR OF HETEROBIMETALLIC CARBONYL-COMPOUNDS OF THE TYPE [W(CO)(4)(BIPY)(CUX)] (X=CL, N-3, CLO4 AND BF4)

Four new heterobimetallic metal carbonyls were synthesized by the reac tion of [W(CO)(4)(bipy)] (1) with copper(I) compounds leading to speci es with the general formula [W(CO)(4)(bipy)(CuX)] (X = Cl, N-3, ClO4, BF4) (2-5). The metal carbonyl compounds were characterized by element al analysis, infrared and UV-visible electronic spectroscopy and therm ogravimetric analysis. The IR data for 2-5 show carbonyl stretching ba nd patterns similar to compound 1; ie they exhibit the same number of bands. The UV-vis results show a dissociation reaction generating the starting compound 1 and CuX as consequence of a weak interaction betwe en 1 and CuX. Thermal decomposition mechanisms as well as the thermal stability are influenced by the CuX fragments. The thermal stability d ecreases in the order [W(CO)(4)(bipy)] > [W(CO)(4)(bipy)(CuCl)] > [W(C O)(4)(bipy)(CuBF4)]. The X-ray results show the formation of WO3, CuWO 4, Cu2O and CuO as final decomposition products. (C) 1997 Elsevier Sci ence Ltd.