Femtosecond to nanosecond studies of octupolar molecules and their quadrupolar and dipolar analogues

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216275%3A25310%2F17%3A39910728" target="_blank" >RIV/00216275:25310/17:39910728 - isvavai.cz</a>

Výsledek na webu

<a href="http://doi.org/10.1039/C7CP01463E" target="_blank" >http://doi.org/10.1039/C7CP01463E</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1039/c7cp01463e" target="_blank" >10.1039/c7cp01463e</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Femtosecond to nanosecond studies of octupolar molecules and their quadrupolar and dipolar analogues

Popis výsledku v původním jazyce

The photophysical properties of two octupolar (T) molecules and of their linear (L) and quadrupolar (Q) analogues are studied by means of steady state and femtosecond to nanosecond spectroscopy. The compounds bear a triphenylamine donor, cyano acceptors and acetylenic (series 1) or olefin (series 2) pi-bridges. In the octupolar compound of series 2 (2T), fluorescence is emitted from an excited state localized on a single branch, while in that of series 1 (1T), the emitting state is delocalized among branches pointing to a reduced excited state polarity. Excited state dynamics in series 1 has shown an increase of lifetime with solvent polarity. In the branched compounds of series 2, multiexponential dynamics in polar solvents is exhibited indicating a distribution of emitting geometries. Femtosecond anisotropy in 1T indicates incoherent excitation transfer on the timescale of a few ps, in agreement with the hopping time predicted by the Forster model. However, no hopping mechanism is observed in 2T possibly because of an increased intramolecular charge transfer leading to a low energy relaxed excited state localized on a single branch.

Název v anglickém jazyce

Femtosecond to nanosecond studies of octupolar molecules and their quadrupolar and dipolar analogues

Popis výsledku anglicky

The photophysical properties of two octupolar (T) molecules and of their linear (L) and quadrupolar (Q) analogues are studied by means of steady state and femtosecond to nanosecond spectroscopy. The compounds bear a triphenylamine donor, cyano acceptors and acetylenic (series 1) or olefin (series 2) pi-bridges. In the octupolar compound of series 2 (2T), fluorescence is emitted from an excited state localized on a single branch, while in that of series 1 (1T), the emitting state is delocalized among branches pointing to a reduced excited state polarity. Excited state dynamics in series 1 has shown an increase of lifetime with solvent polarity. In the branched compounds of series 2, multiexponential dynamics in polar solvents is exhibited indicating a distribution of emitting geometries. Femtosecond anisotropy in 1T indicates incoherent excitation transfer on the timescale of a few ps, in agreement with the hopping time predicted by the Forster model. However, no hopping mechanism is observed in 2T possibly because of an increased intramolecular charge transfer leading to a low energy relaxed excited state localized on a single branch.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

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OECD FORD obor

10401 - Organic chemistry

Projekt

—

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2017

Kód důvěrnosti údajů

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

Název periodika

Physical Chemistry Chemical Physics

ISSN

1463-9076

e-ISSN

—

Svazek periodika

19

Číslo periodika v rámci svazku

25

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

13

Strana od-do

16485-16497

Kód UT WoS článku

000404530600021

EID výsledku v databázi Scopus

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