Excited Singlet State Of Trans-stilbene Research Articles

Viscosity heterogeneity inside lipid bilayers of single-component phosphatidylcholine liposomes observed with picosecond time-resolved fluorescence spectroscopy.

A number of biochemical reactions proceed inside biomembranes. Because the rate of a chemical reaction is influenced by chemical properties of the reaction field, it is important to examine the chemical properties inside the biomembranes, or lipid bilayer membranes, for understanding biochemical reactions. In this study, we estimate viscosity inside the lipid bilayers of liposomes with picosecond time-resolved fluorescence spectroscopy. trans-Stilbene is solubilized in the lipid bilayers formed by phosphatidylcholines, DSPC, DOPC, DPPC, DMPC, and DLPC, with 18, 18, 16, 14, and 12 carbon atoms in their alkyl chains, respectively, and egg-PC. Viscosity inside the lipid bilayer is estimated from the photoisomerization rate constant and from the rotational relaxation time of the first excited singlet state of trans-stilbene. The effect of the hydrocarbon chain length and temperature on viscosity is examined. The presence of two solvation environments within the lipid bilayer is indicated from the two independent estimations. One environment is 30 to 290 times more viscous than the other. Even single-component lipid bilayers are likely to have heterogeneous structures.

Physical Chemistry of the Lowest Excited Singlet State of trans-Stilbene in Solution as Studied by Time-Resolved Raman Spectroscopy

Abstract Structure and dynamics of the lowest excited singlet state of trans-stilbene (the S1 state of tSB) in solution are discussed with an emphasis placed on the elucidation of the mechanism of the trans–cis photoisomerization. Structure of S1 tSB in solution is first discussed based on the time-resolved Raman spectral data and their isotope substitution effects. Original data for an asymmetrically deuteriated tSB, tSB-d5, are presented to confirm the ethylene-like structure of the central C–C linkage of S1 tSB. Next, the time-, temperature-, and solvent-dependent band shape changes of the olefinic C=C stretch band are discussed in terms of the solvent induced dynamic polarization. It is shown that the dynamic polarization model accounts very well, not only for the observed band shape changes, but also for their relevance to the isomerization mechanism. A new microscopic view on the photoisomerization of tSB is thus presented. Picosecond energy dissipation process of S1 tSB is then discussed in relation to the microscopic solvation structure in chloroform. Finally, the mechanism of a new bimolecular reaction between S1 tSB and carbon tetrachloride is discussed on the basis of the diffusion-controlled reaction model.

Anomalous Lifetime Shortening of S1 trans-Stilbene in Carbon Tetrachloride as Revealed by Picosecond Time-resolved Raman, Absorption, and Fluorescence Spectroscopies

Abstract The lifetime of the first excited singlet state of trans-stilbene (S1 tSB) in carbon tetrachloride at room temperature is determined to be 3.1 ± 0.2 ps with the use of time-resolved Raman, absorption, and fluorescence spectroscopies. The lifetime of 3.1 ps is shorter than the shortest value ever reported by an order of magnitude. The steady state photoirradiation of tSB in carbon tetrachloride shows that the decomposition of the tSB molecule is the primary cause of the lifetime shortening.

Picosecond dynamics of trans-stilbene photodimerization

Picosecond absorption spectroscopy is used to examine the dynamics of the 2+2 photodimerization reaction of trans-stilbene in benzene. The quenching of the first excited singlet state of trans-stilbene by ground-state trans-stilbene occurs at the diffusion limit, 2.03×10 10 M -1 s -1 . Upon quenching, a new intermediate is formed with a λ max of 480 nm which is characteristic of the charge-transfer species. The rate of the decay of the transient species is (2.40±0.37)×10 9 s -1 . The assignment of the transient to the excimer or a biradicaloid species at the pericyclic minimum is discussed

Theoretical analysis of the force field of the lowest excited singlet state of trans-stilbene

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTTheoretical analysis of the force field of the lowest excited singlet state of trans-stilbeneFabrizia Negri, Giorgio Orlandi, and Francesco ZerbettoCite this: J. Phys. Chem. 1989, 93, 13, 5124–5128Publication Date (Print):June 1, 1989Publication History Published online1 May 2002Published inissue 1 June 1989https://doi.org/10.1021/j100350a020RIGHTS & PERMISSIONSArticle Views82Altmetric-Citations45LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (597 KB) Get e-Alerts

Stilbene photocycloaddition reactions: ion pair and electron transfer dynamics

Abstract

Solvent influence on photoisomerization dynamicsa)

The rate constants of the nonradiative decay process of the excited singlet state of trans-stilbene and trans-1,1′-biindanylidene (‘‘stiff ’’ stilbene) were measured in liquid n-alkanes at room temperature. These data were compared with the two models for isomerization in condensed phases proposed by Kramers and by Grote and Hynes. For trans-stilbene, the agreement with Kramers’ model was unsatisfactory, whereas better agreement was obtained with Grote and Hynes’ model. The data for stiff stilbene agreed well with Kramers’ model in the Smoluchowski limit. These results were explained in terms of the shape of the potential energy barrier which separates the trans from the twisted configuration of the excited singlet state of these molecules. It is suggested that the deviation between theory and experiment is a result of a qualitative difference in the microscopic solvent–solute collisional interaction when the solvent molecules are longer than stilbene. The best fit of theory to experiment for trans-stilbene requires the use of an unphysically low (8 cm−1) frequency for the top of the barrier to isomerization.