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a b s t r a c tIn this study, Co, Cr or Au 3+ functional polystyrene-block-poly(2-vinylpyridine), PS-b-P2VP complexes were prepared and characterized. Coordination of metal atom or ion to nitrogen atom of pyridine rings was confirmed by FTIR analyses. The strength and efficiency of coordination of P2VP blocks to Co, Cr or Au 3+ mainly depends on charge and stability of the complex formed that is mainly related to the energy of d orbitals. The results reveal that the thermal stability of the polymer composite formed increases with the increase in strength of the coordination. Changes in thermal decomposition mechanism and product distribution were recorded. Degradation of P2VP units coordinated to Cr, Co or Au 3+ was started by loss of pyridine units leaving an unsaturated and/or crosslinked polymer backbone that degraded at relatively high temperatures.

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The electrochemical behaviour of pentacarbonyl(pyrazine)metal(0) complexes of the group 6 elements was studied by cyclic voltammetry in dichloromethane-(n-Bu)4NBF4 solventelectrolyte couple at -20°C vs. Ag/Ag+ or SCE reference electrode. Constant potential electrolyses of the complexes were carried out at their first oxidation peak potentials and monitored in situ by UV-Vis spectrometry. Electrolysis of W(CO)5pz produces [W(CO)5pz]+ and a similar electrochemical mechanism is expected both for Cr(CO)5pz and Mo(CO)5pz complexes. In situ low temperature constant current ESR electrolysis also confirmed the production of [W(CO)5pz]+ after the electron transfer.