Počet záznamů: 1
Vibrational Relaxation and Redistribution Dynamics in Ruthenium(II) Polypyridyl-Based Charge-Transfer Excited States: A Combined Ultrafast Electronic and Infrared Absorption Study
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SYSNO ASEP 0494623 Druh ASEP J - Článek v odborném periodiku Zařazení RIV J - Článek v odborném periodiku Poddruh J Článek ve WOS Název Vibrational Relaxation and Redistribution Dynamics in Ruthenium(II) Polypyridyl-Based Charge-Transfer Excited States: A Combined Ultrafast Electronic and Infrared Absorption Study Tvůrce(i) Brown, A. M. (US)
McCusker, C. E. (US)
Carey, M. C. (US)
Blanco-Rodríguez, A. M. (GB)
Towrie, M. (GB)
Clark, I. P. (GB)
Vlček, Antonín (UFCH-W) RID, ORCID
McCusker, J. K. (US)Zdroj.dok. Journal of Physical Chemistry A. - : American Chemical Society - ISSN 1089-5639
Roč. 122, č. 40 (2018), s. 7941-7953Poč.str. 13 s. Jazyk dok. eng - angličtina Země vyd. US - Spojené státy americké Klíč. slova Chromophores ; Charge transfer ; Density functional theory Vědní obor RIV CF - Fyzikální chemie a teoretická chemie Obor OECD Physical chemistry CEP GA17-01137S GA ČR - Grantová agentura ČR Institucionální podpora UFCH-W - RVO:61388955 UT WOS 000447471400002 EID SCOPUS 85054281438 DOI 10.1021/acs.jpca.8b06197 Anotace Ultrafast time-resolved electronic and infrared absorption measurements have been carried out on a series of Ru(II) polypyridyl complexes in an effort to delineate the dynamics of vibrational relaxation in this class of charge transfer chromophores. Time-dependent density functional theory calculations performed on compounds of the form [Ru(CN-Me-bpy)x(bpy)3-x]2+(x = 1-3 for compounds 1-3, respectively, where CN-Me-bpy is 4,4′-dicyano-5,5′-dimethyl-2,2′-bipyridine and bpy is 2,2′-bipyridine) reveal features in their charge-transfer absorption envelopes that allow for selective excitation of the Ru(II)-(CN-Me-bpy) moiety, the lowest-energy MLCT state(s) in each compound of the series. Changes in band shape and amplitude of the time-resolved differential electronic absorption data are ascribed to vibrational cooling in the CN-Me-bpy-localized3MLCT state with a time constant of 8 ± 3 ps in all three compounds. This conclusion was corroborated by picosecond time-resolved infrared absorption measurements, sharpening of the CN stretch in the3MLCT excited state was observed with a time constant of 3.0 ± 1.5 ps in all three members of the series. Electronic absorption data acquired at higher temporal resolution revealed spectral modulation over the first 2 ps occurring with a time constant of Γ = 170 ± 50 fs, in compound 1, corresponding effects are significantly attenuated in compound 2 and virtually absent in compound 3. We assign this feature to intramolecular vibrational redistribution (IVR) within the3MLCT state and represents a rare example of this process being identified from time-resolved electronic absorption data for this important class of chromophores. Pracoviště Ústav fyzikální chemie J.Heyrovského Kontakt Michaela Knapová, michaela.knapova@jh-inst.cas.cz, Tel.: 266 053 196 Rok sběru 2019
Počet záznamů: 1