6533b823fe1ef96bd127dffe

RESEARCH PRODUCT

Time-resolved photoisomerization of 1,1′-di-tert-butylstilbene and 1,1′-dicyanostilbene

Martin QuickA. L. DobryakovS. A. KovalenkoNikolaus P. ErnstingHeiner DetertD. Lenoir

subject

010304 chemical physicsPhotoisomerizationChemistryRelaxation (NMR)Analytical chemistryGeneral Physics and Astronomy010402 general chemistry01 natural sciences0104 chemical sciencesDipolechemistry.chemical_compoundAbsorption bandElectron affinity0103 physical sciencesUltrafast laser spectroscopyPhysical and Theoretical ChemistrySpectroscopyAcetonitrile

description

Abstract Photoisomerization of 1,1′-di-tert-butylstilbene ( 3 ) and 1,1′-dicyanostilbene ( 4 ) is monitored with stationary and broadband transient absorption spectroscopy. The electron affinity of the substituents correlates with the shift of the absorption band. The weak extinction of 3 complicates data interpretation, but comparison with earlier measured 1,1′-dimethylstilbene ( 1 ) and 1,1′-diethylstilbene ( 2 ) helps to assign transient spectra and relaxation paths. For 3 a long-lived perpendicular state P is observed with lifetime τ P  = 134 ps in acetonitrile. For 4 τ P  = 2.1 ps in acetonitrile and 27 ps in n-hexane, the difference indicating a substantial dipole moment (∼3D) of the P state.

https://doi.org/10.1016/j.cplett.2016.04.060