| Texto completo | |
| Autor(es): |
Sihn, Luca M.
;
Vadell, Robert B.
;
Araujo, Rafael B.
;
Mukherjee, Atripan
;
Kloz, Miroslav
;
Sa, Jacinto
;
Toma, Henrique E.
Número total de Autores: 7
|
| Tipo de documento: | Artigo Científico |
| Fonte: | Physical Chemistry Chemical Physics; v. 27, n. 33, p. 10-pg., 2025-07-28. |
| Resumo | |
The photophysical study of decarboxyranelic acid (DRAc), a thiophene derivative made from strontium ranelate, shows that it can form long-lived radical cation species through a pathway involving triplet states. Femtosecond transient absorption spectroscopy and computational modeling reveal a fast intersystem crossing (ISC) process in water, with a time constant of 1.1 ps and a quantum yield of 27%. The small energy gap between the S1 and T1 states, along with the mixed pi sigma* character of the S1 state, contributes to this rapid ISC, in line with El-Sayed's rule. The results indicate that DRAc's photoreactivity is strongly influenced by the solvent: in water, the high hydrogen-bond donor capacity stabilizes the S1 state, narrows the energy gap, and creates an almost barrier-free ISC pathway. Studies using deuterated solvents show that the ISC rate increases due to stronger stabilization of the S1 state by deuterium bonds. Overall, these results make DRAc a useful model for studying heavy-atom-free molecules with efficient ISC and radical formation, with potential applications in photodynamic therapy and catalysis. (AU) | |
| Processo FAPESP: | 18/21489-1 - Nanotecnologia supramolecular: design, materiais e dispositivos |
| Beneficiário: | Henrique Eisi Toma |
| Modalidade de apoio: | Auxílio à Pesquisa - Temático |
| Processo FAPESP: | 18/25974-1 - Fotoquímica, fotofísica e fotoeletroquímica do íon ranelato |
| Beneficiário: | Luca Michael Sihn |
| Modalidade de apoio: | Bolsas no Brasil - Doutorado Direto |