dc.creator | Rodriguez-Serrano, Angela | |
dc.creator | Rai-Constapel, Vidisha | |
dc.creator | Daza, Martha C. | |
dc.creator | Doer, Markus | |
dc.creator | Marian, Christel M. | |
dc.date.accessioned | 2020-02-18T14:34:50Z | |
dc.date.accessioned | 2022-09-28T15:09:06Z | |
dc.date.available | 2020-02-18T14:34:50Z | |
dc.date.available | 2022-09-28T15:09:06Z | |
dc.date.created | 2020-02-18T14:34:50Z | |
dc.date.issued | 2012-12-01 | |
dc.identifier | http://hdl.handle.net/11634/21757 | |
dc.identifier | https://doi.org/10.1039/c2pp25224d | |
dc.identifier.uri | http://repositorioslatinoamericanos.uchile.cl/handle/2250/3670109 | |
dc.description.abstract | A study of the possible intersystem crossing (ISC) mechanisms (S ⇝ T) in thionine (3,7-diamino-phenothiazin-5-ium), which is conducive to the efficient population of the triplet manifold, is presented. The radiationless deactivation channels {S1,S2(π → π*) ⇝ T1,T2(π → π*)} have been examined. Since the direct ISC does not explain the high triplet quantum yield in this system, attention has been centered on the vibronic spin–orbit coupling between the low-lying singlet and triplet (π → π*) states of interest. An efficient population transfer from the S1(πH → πL*) state to the T2(πH−1 → πL*) state via this channel is confirmed. The calculated ISC rate constant for this channel is kISC ≈ 3.35 × 108 s−1, which can compete with the radiative depopulation of the S1(πH → πL*) state via fluorescence (kF ≈ 1.66 × 108 s−1) in a vacuum. The S1(πH → πL*) ⇝ T1(πH → πL*) and {S2(πH−1 → πL*) ⇝ T1,T2(π → π*)} ISC channels have been estimated to be less efficient (kISC ≈ 105–106 s−1). Based on the computed ISC rate constants and excited-state solvent shifts, it is suggested that the efficient triplet quantum yield of thionine in water is primarily due to the S1(πH → πL*) ⇝ T2(πH−1 → πL*) channel with a computed rate constant of the order of 108–109 s−1 which is in accord with the experimental finding (kISC = 2.8 × 109 s−1). | |
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dc.rights | http://creativecommons.org/licenses/by-nc-sa/2.5/co/ | |
dc.rights | Atribución-NoComercial-CompartirIgual 2.5 Colombia | |
dc.title | A theoretical study of thionine: spin–orbit coupling and intersystem crossing | |
dc.type | Generación de Nuevo Conocimiento: Artículos publicados en revistas especializadas - Electrónicos | |