Femtosecond Fluorescence and Intersystem Crossing in Rhenium(I) Carbonyl-Bipyridine Complexes

0309946 - ÚFCH JH 2009 RIV US eng J - Journal Article
Cannizzo, A. - Blanco-Rodríguez, A. M. - Nahhas, A. E. - Šebera, Jakub - Záliš, Stanislav - Vlček, Antonín - Chergui, M.
Femtosecond Fluorescence and Intersystem Crossing in Rhenium(I) Carbonyl-Bipyridine Complexes.
[Femtosekundová fluorescence a vnitřní přenos energie u série rheniových(I) bipyridinových karbonylových komplexů.]
Journal of the American Chemical Society. Roč. 130, č. 28 (2008), s. 8967-8974. ISSN 0002-7863. E-ISSN 1520-5126
R&D Projects: GA MŠMT 1P05OC068
Institutional research plan: CEZ:AV0Z40400503
Keywords : rhenium(I) * carbonyl-bipyridine * intersystem crossing
Subject RIV: CF - Physical ; Theoretical Chemistry
Impact factor: 8.091, year: 2008

Ultrafast electronic-vibrational relaxation upon excitation of the singlet charge-transfer b1A´ state of [Re(L)(CO)3(bpy)]n (L=Cl,Br,I, n=0; L=4-Et-pyridine, n=1+) in acetonitrile was investigated using the femtosecond fluorescence up-conversion technique with polychromatic detection. In addition, energies, characters, and molecular structures of the emitting states were calculated by TD-DFT. The luminescence is characterized by a broad fluorescence band at very short times, and evolves to the steady-state phosphorescence spectrum from the a3A" state at longer times. The analysis of the data allows us to identify three spectral components. The first two are characterized by decay times .tau.1 = 85-150 fs and .tau.2 = 340-1200 fs, depending on L, and are identified as fluorescence from the initially excited singlet state and phosphorescence from a higher triplet state (b3A"), respectively. The third component corresponds to the long-lived phosphorescence from the lowest a3A" state.

Pomocí femtosekundové spektroskopie byl studován nejníže ležící dovolený singletní stav b1A´ a následná luminiscence u série komplexů [(Re)(L)(CO)3(bpy)]n (L = Cl, Br, n=0; L = 4-Et-pyridin, n=1+) v acetonitrilu. Experimentální studium těchto komplexů bylo doprovázeno kvantověchemickými DFT a TD-DFT výpočty.
Permanent Link: http://hdl.handle.net/11104/0161956