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

• Published in: Inorganica Chimica Acta 2011-05, Vol.370 (1), p.482-491
• Main Authors: Bracco, Larisa L.B., Lezna, Reynaldo O., Muñoz-Zuñiga, Jackeline, Ruiz, Gustavo T., Féliz, Mario R., Ferraudi, Guillermo J., García Einschlag, Fernando S., Wolcan, Ezequiel
• Format: Article
• Language: English
• Subjects: Phenanthroline; Polymers; Pulse radiolysis; Radicals; Reduction; Rhenium
• ISSN: 0020-1693; 1873-3255
• DOI: 10.1016/j.ica.2011.02.039

The electrochemical reduction in aprotic media of-[Re I(CO) 3L] + pendants in poly-4-vinylpyridine polymers is compared to that of [Re I(CO) 3L] + complexes (L= 5-nitro-1,10-phenanthroline and 3,4,7,8-tetramethyl-1,10-phenanthroline). The reaction of e solv - and/or C H 2 OH with -[ Re I ( CO ) 3 ( NO 2 - phen ) ] + -containing polymers generates -[ Re I ( CO ) 3 ( NO 2 - - phen ) ] pendants which after disproportionation give rise to products with λ max = 380 nm . The kinetic behavior of -[ Re I ( CO ) 3 ( NO 2 - -phen ) ] pendants under different experimental conditions is discussed. [Display omitted] ► Electrochemical reduction in aprotic media of –[Re I(CO) 3L] + pendants in poly-4-vinylpyridine polymers. ► Pulse radiolysis of –[Re I(CO) 3L] + pendants in poly-4-vinylpyridine polymers. ► Reduced radical anions formed by reaction with solvated electrons and C H 2OH radicals. Azodioxy phenanthroline based Re-products. The electrochemical reduction in aprotic media of –[Re I(CO) 3L] + pendants in poly-4-vinylpyridine polymers is compared to that of [Re I(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 (NO 2-phen) and 3,4,7,8-tetramethyl-1,10-phenanthroline (tmphen) were obtained by spectro-electrochemistry of [Re I(CO) 3(NO 2-phen)(CH 3CN)] + and [Re I(CO) 3(tmphen)(CH 3CN)] +, respectively. Similar spectra were obtained for the radical anions NO 2 - -phen and tmphen − after pulse radiolysis experiments with –[Re I(CO) 3L] +-containing polymers. The analysis of the time-resolved difference spectra was performed using “multivariate curve resolution” (MCR) techniques. Unlike e solv - , C H 2OH radicals were unable to reduce tmphen ligands. The reaction of e solv - and/or C H 2OH with –[Re I(CO) 3(NO 2-phen)] +-containing polymers generates –[Re I(CO) 3( NO 2 - -phen)] pendants which after disproportionation give rise to products with λ max = 380 nm. The kinetic behavior of –[Re I(CO) 3( NO 2 - -phen)] pendants under different experimental conditions is discussed.