Vibrational Relaxation and Redistribution Dynamics in Ruthenium(II) Polypyridyl-Based Charge-Transfer Excited States: A Combined Ultrafast Electronic and Infrared Absorption Study

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61388955%3A_____%2F18%3A00494623" target="_blank" >RIV/61388955:_____/18:00494623 - isvavai.cz</a>

Výsledek na webu

<a href="http://dx.doi.org/10.1021/acs.jpca.8b06197" target="_blank" >http://dx.doi.org/10.1021/acs.jpca.8b06197</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1021/acs.jpca.8b06197" target="_blank" >10.1021/acs.jpca.8b06197</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Vibrational Relaxation and Redistribution Dynamics in Ruthenium(II) Polypyridyl-Based Charge-Transfer Excited States: A Combined Ultrafast Electronic and Infrared Absorption Study

Popis výsledku v původním jazyce

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.

Název v anglickém jazyce

Vibrational Relaxation and Redistribution Dynamics in Ruthenium(II) Polypyridyl-Based Charge-Transfer Excited States: A Combined Ultrafast Electronic and Infrared Absorption Study

Popis výsledku anglicky

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.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10403 - Physical chemistry

Projekt

<a href="/cs/project/GA17-01137S" target="_blank" >GA17-01137S: Přenos elektronu v (bio)molekulárních systémech: časově rozlišená vibrační spektroskopie a teorie</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2018

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Journal of Physical Chemistry A

ISSN

1089-5639

e-ISSN

—

Svazek periodika

122

Číslo periodika v rámci svazku

40

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

13

Strana od-do

7941-7953

Kód UT WoS článku

000447471400002

EID výsledku v databázi Scopus

2-s2.0-85054281438