Effect of Temperature on Photoisomerization Dynamics of a Newly Designed Two-Stroke Light-Driven Molecular Rotary Motor.
Int J Mol Sci
; 23(17)2022 Aug 26.
Article
em En
| MEDLINE
| ID: mdl-36077091
ABSTRACT
The working mechanism of conventional light-driven molecular rotary motors, especially Feringa-type motors, contains two photoisomerization steps and two thermal helix inversion steps. Due to the existence of a thermal helix inversion step, both the ability to work at lower temperatures and the rotation speed are limited. In this work, a two-stroke light-driven molecular rotary motor, 2-(1,5-dimethyl-4,5-dihydrocyclopenta[b]pyrrol-6(1H)-ylidene)-1,2-dihydro-3H-pyrrol-3-one (DDPY), is proposed, which is capable of performing unidirectional and repetitive rotation by only two photoisomerization (EPâZP and ZPâEP) steps. With trajectory surface-hopping simulation at the semi-empirical OM2/MRCI level, the EPâZP and ZPâEP nonadiabatic dynamics of DDPY were systematically studied at different temperatures. Both EPâZP and ZPâEP photoisomerizations are on an ultrafast timescale (ca. 200-300 fs). The decay mode of EPâZP photoisomerization is approximately bi-exponential, while that of ZPâEP photoisomerization is found to be periodic. For EP and ZP isomers of DDPY, after the S0âS1 excitation, the dynamical processes of nonadiabatic decay are both followed by twisting about the central C=C double bond and the pyramidalization of the C atom at the stator-axle linkage. The effect of temperature on the nonadiabatic dynamics of EPâZP and ZPâEP photoisomerizations of DDPY has been systematically investigated. The average lifetimes of the S1 excited state and quantum yields for both EPâZP and ZPâEP photoisomerization are almost temperature-independent, while the corresponding unidirectionality of rotation is significantly increased (e.g., 74% for EPâZP and 72% for ZPâEP at 300 K vs 100% for EPâZP and 94% for ZPâEP at 50 K) with lowering the temperature.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Acidente Vascular Cerebral
Limite:
Humans
Idioma:
En
Revista:
Int J Mol Sci
Ano de publicação:
2022
Tipo de documento:
Article
País de afiliação:
China
País de publicação:
CH
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SUIZA
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SUÍÇA
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SWITZERLAND