Time-resolved emission spectra of 4-dimethylamino-4¡ä-cyano-stilbene and resveratrol in high viscosity solvents and silica matrices

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• 作者：Ma?gorzata Borowiak ; Beata Grobelna ; Anna Synak ; Piotr Bojarski ; Aleks ; er A. Kubicki
• 关键词：Stilbene ; Resveratrol ; Time-resolved emission spectra ; Photoisomerization ; Intramolecular charge transfer
• 刊名：Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy
• 出版年：2013
• 出版时间：November, 2013
• 年：2013
• 卷：115
• 期：Complete
• 页码：111-117
• 全文大小：1788 K

文摘

Time-resolved emission spectra of 4-dimethylamino-4¡ä-cyano-stilbene (DMACS) and 3,5,4¡ä-trihydroxy-stilbene (resveratrol, RSV) in propylene glycol and in rigid silica xerogel matrix at 23 ¡ãC were studied. For the polar molecule DMACS in propylene glycol, a 66 nm shift of maximum wavelength of emission spectra was observed within 1 ns after excitation, and most of the shift occurred during the first 200 ps. For resveratrol in propylene glycol no such a shift was observed. The rigid silica environment eliminates some deactivation pathways and stabilizes spectroscopic properties of both molecules. Spectral properties of nonpolar and high dipole moment molecules in viscous liquids and rigid environments are compared. Results are explained on the basis of intramolecular processes and solute-solvent relaxation, as well.