INQUIMAE   12526
INSTITUTO DE QUIMICA, FISICA DE LOS MATERIALES, MEDIOAMBIENTE Y ENERGIA
Unidad Ejecutora - UE
artículos
Título:
Spectroscopic signatures of ligand field states in {RuII(imine)} complexes
Autor/es:
CADRANEL, ALEJANDRO; KUNO, MASARU K; PIESLINGER, GERMAN E.; BARALDO, LUIS M.; TONGYING, PORNTHIP; HODAK, JOSÉ H.
Revista:
DALTON TRANSACTIONS
Editorial:
ROYAL SOC CHEMISTRY
Referencias:
Lugar: CAMBRIDGE; Año: 2016 vol. 45 p. 5464 - 5464
ISSN:
1477-9226
Resumen:
Ligand field (LF) states have been present in discussions on the photophysics and photochemistry of ruthenium-iminic chromophores for decades, although there is very little documented direct evidence of them. We studied the picosecond transient absorption (TA) spectroscopy of four {RuII(imine)} complexes that respond to the formula trans-[Ru(L)4(X)2], where L is either pyridine (py) or 4-methoxypyridine (MeOpy) and X is either cyanide or thiocyanate. Dicyano compounds behave as most ruthenium polypyri- dines and their LF states remain silent. In contrast, in the dithiocyanate complexes we found clear spectroscopic evidence of the participation of LF states in the MLCT decay pathway. These states are of donor and acceptor character simultaneously and this is manifested in the presence of MLCT and LMCT transient absorption bands of similar energy. Spectroelectrochemical techniques supported the interpret- ation of the absorption features of MLCT states, and DFT methods helped to assign their spectroscopic signatures and provided strong evidence on the nature of LF states.