title: Time-resolved emission spectra of 4-dimethylamino-4'-cyano-stilbene and resveratrol in high viscosity solvents and silica matrices.
abstract: Time-resolved emission spectra of 4-dimethylamino-4'-cyano-stilbene (DMACS) and 3,5,4'-trihydroxy-stilbene (resveratrol, RSV) in propylene glycol and in rigid silica xerogel matrix at 23°C were studied. For the polar molecule DMACS in propylene glycol, a 66nm shift of maximum wavelength of emission spectra was observed within 1ns after excitation, and most of the shift occurred during the first 200ps. 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.
authors.affiliation: University of Gdańsk, Institute of Experimental Physics, Molecular Spectroscopy Division, 80-952 Gdańsk, Wita Stwosza 57, Poland.
authors.forename: Małgorzata
authors.initials: M
authors.lastname: Borowiak
authors.forename: Beata
authors.initials: B
authors.lastname: Grobelna
authors.forename: Anna
authors.initials: A
authors.lastname: Synak
authors.forename: Piotr
authors.initials: P
authors.lastname: Bojarski
authors.forename: Aleksander A
authors.initials: AA
authors.lastname: Kubicki
mesh_terms: D009570:Nitriles / Q000737:chemistry*; D019946:Propylene Glycol / Q000737:chemistry*; D000077185:Resveratrol; D058428:Silica Gel / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D013267:Stilbenes / Q000737:chemistry*; D013997:Time Factors; D014783:Viscosity
chemical_list: C116158:4-(dimethylamino)-4'-cyanostilbene; D009570:Nitriles; D012997:Solvents; D013267:Stilbenes; D058428:Silica Gel; D019946:Propylene Glycol; D000077185:Resveratrol
keywords: Intramolecular charge transfer; Photoisomerization; Resveratrol; Stilbene; Time-resolved emission spectra