On the mechanism of formation and spectral properties of radical anions generated by the reduction of –[ReI(CO)3(5-nitro-1,10-phenanthroline)]+ and –[ReI(CO)3(3,4,7,8-tetramethyl-1,10-phenanthroline)]+ pendants in poly-4-vinylpyridine polymers

The electrochemical reduction in aprotic media of –[ReI(CO)3L]+ pendants in poly-4-vinylpyridine polymers is compared to that of [ReI(CO)3L]+ complexes (L = 5-nitro-1,10-phenanthroline and 3,4,7,8-tetramethyl-1,10-phenanthroline). The UV–Vis absorption spectra of the reduced radical anions of 5-nitro-1,10-phenanthroline (NO2-phen) and 3,4,7,8-tetramethyl-1,10-phenanthroline (tmphen) were obtained by spectro-electrochemistry of [ReI(CO)3(NO2-phen)(CH3CN)]+ and [ReI(CO)3(tmphen)(CH3CN)]+, respectively. Similar spectra were obtained for the radical anions NO 2 - -phen and tmphen− after pulse radiolysis experiments with –[ReI(CO)3L]+-containing polymers. The analysis of the time-resolved difference spectra was performed using “multivariate curve resolution” (MCR) techniques. Unlike e solv - , CH2OH radicals were unable to reduce tmphen ligands. The reaction of e solv - and/or CH2OH with –[ReI(CO)3(NO2-phen)]+-containing polymers generates –[ReI(CO)3( NO 2 - -phen)] pendants which after disproportionation give rise to products with λmax = 380 nm. The kinetic behavior of –[ReI(CO)3( NO 2 - -phen)] pendants under different experimental conditions is discussed.