Synthesis, characterization and thermal behavior of heterobimetallic carbonyl compounds of the type [W(CO) 4(bipy)(CuX)](X = Cl, N 3, ClO 4 and BF 4)

Abstract

Four new heterobimetallic metal carbonyls were synthesized by the reaction of [W(CO) 4(bipy)] ( 1) with copper(I) compounds leading to species with the general formula [W(CO) 4(bipy)(CuX)] (X = Cl, N 3, ClO 4, BF 4) ( 2–5). The metal carbonyl compounds were characterized by elemental analysis, infrared and UV-visible electronic spectroscopy and thermogravimetric analysis. The IR data for 2–5 show carbonyl stretching band 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 between 1 and CuX. Thermal decomposition mechanisms as well as the thermal stability are influenced by the CuX fragments. The thermal stability decreases in the order [W(CO) 4(bipyl)]>[W(CO) 4(bipy)(CuCl)]>[W(CO) 4(bipy)(CuBF 4)]. The X-ray results show the formation of WO 3, CuWO 4, Cu 2O and CuO as final decomposition products.