Photochemical and electrochemical Z–E isomerization of 1,4-dialkoxy-2,5-bis[2-(thien-2-yl)ethenyl]benzene stereoisomers

Waskiewicz, Krzysztof; Gabanski, Rafal; Motyka, Radosław; Łapkowski, Mieczysław; Suwiński, J.; Żak, Jerzy

doi:10.1016/j.jelechem.2008.01.021

Cited by 2 publications

(13 citation statements)

References 32 publications

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“…The absorption spectrum of EE -DMTB measured in chloroform shows a strong absorption centered at 416 nm (2.98 eV) and two intense peaks at 355 and ∼210 nm (3.49 and 5.90 eV) with the shoulder at 262 nm (4.73 eV). The observed spectrum is in accordance with that from the previous study . The photoisomerization process of DMTB stereoisomers can be observed when the EE -, EZ -, or ZZ - isomer in solution is exposed to UV radiation.…”

Section: Resultssupporting

confidence: 90%

“…The photoisomerization for ZZ → EZ → EE and EZ → EE was observed in ref . The transient spectra are also observed in the present work.…”

Section: Resultssupporting

confidence: 86%

“…The absorption spectra of these isomers were calculated by the direct SAC–CI method with the TD-CAM-B3LYP (PCM-SS) correction. The results are summarized in Table with the experimental values extracted from the UV–vis spectra observed in the previous work . In Figure , theoretical spectra are compared with the UV–vis spectra in the range of 200–500 nm.…”

Section: Resultsmentioning

confidence: 90%

“…In Figure , theoretical spectra are compared with the UV–vis spectra in the range of 200–500 nm. We also observed the transient absorption spectra contributed from EZ - and ZZ - isomers; however, the decomposition of the spectra into each isomer is not possible so that we compared our theoretical spectra with the previous ones . As can be seen in Figure , the direct SAC–CI calculations reproduced the experimental spectra in both peak positions and absorption intensity satisfactorily compared to the characteristics of the EE - isomer; the absorption peaks of the EZ - and ZZ -DMTB isomers shift to the higher-energy region compared to those of the EE - isomer, which reflects the shorter effective π-conjugation length of the two isomers, with the absorption intensity in the low-energy region decreasing.…”

Section: Resultsmentioning

confidence: 99%

“…The DMTB (C 20 H 18 O 2 S 2 ) was synthesized according to the conventional procedure described in the literature, as shown in Scheme . , The 1,4-dimethoxy benzene was chloromethylated with formaldehyde and HCl in dioxane solution. The reaction product then was treated with triphenylphosphine to produce the corresponding salt, which was directly used for the Wittig’s reaction with 2-thienylcarboaldehyde in potassium carbonate/dry methanol to give the product of DMTB as a pale-yellow oil after chromatographic purification.…”

Section: Experimental and Computational Detailsmentioning

confidence: 99%

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Photophysical Properties and Photochemistry ofEE-,EZ-, andZZ-1,4-Dimethoxy-2,5-bis[2-(thien-2-yl)ethenyl] Benzene in Solution: Theory and Experiment

Suramitr¹,

Phalinyot²,

Wolschann

et al. 2012

J. Phys. Chem. A

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Photophysical properties and photoisomerization of 1,4-dimethoxy-2,5-bis[2-(thien-2-yl)ethenyl] benzene (DMTB) have been investigated for the EE-, EZ-, and ZZ- stereoisomers. The EE-DMTB was prepared, and the absorption/fluorescence spectra of EE- isomer as well as transient spectra in photoisomerization among three isomers were observed. Absorption and fluorescence spectra of three isomers were analyzed by the symmetry-adapted cluster-configuration interaction (SAC-CI) and time-dependent density functional theory (TDDFT) methods. The characteristics of the absorption spectra of three isomers were satisfactorily reproduced by the direct SAC-CI and TDDFT methods in both peak position and intensity. The relative stability of three isomers and the photoisomerization among these isomers were also examined theoretically. The ground (S(0)) and first excited state (S(1)) geometries were calculated by the DFT/TDDFT method with the M06HF functional, and the calculated S(0) structures of EE- and ZZ- isomers agreed well with those of the X-ray structures. The geometry relaxation in the S(1) state was interpreted with regard to the excitation character. The solvent effect in the absorption and fluorescence spectra was examined by the polarizable continuum model (PCM) and was found to be 0.05-0.20 eV, reflecting the charge polarization. The results show that the photophysical properties of DMTB can be controlled with the conformation constraint and also indicate the possibility of a photofunctional molecular device such as a switching function.

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Section: Resultssupporting

confidence: 90%

“…The photoisomerization for ZZ → EZ → EE and EZ → EE was observed in ref . The transient spectra are also observed in the present work.…”

Section: Resultssupporting

confidence: 86%

Section: Resultsmentioning

confidence: 90%

Section: Resultsmentioning

confidence: 99%

Section: Experimental and Computational Detailsmentioning

confidence: 99%

See 3 more Smart Citations

Photophysical Properties and Photochemistry ofEE-,EZ-, andZZ-1,4-Dimethoxy-2,5-bis[2-(thien-2-yl)ethenyl] Benzene in Solution: Theory and Experiment

Suramitr¹,

Phalinyot²,

Wolschann

et al. 2012

J. Phys. Chem. A

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Studies on the Nuances of the Electrochemically Induced Room Temperature Isomerization of cis-Stilbene in Acetonitrile and Ionic Liquids

et al. 2014

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Electrochemical reduction of cis-stilbene occurs by two well-resolved one-electron reduction steps in acetonitrile with (n-Bu)4NPF6 as the supporting electrolyte and in N-butyl-N-methylpyrrolidinium (Pyrr1,4(+)) and (trimethylamine)(dimethylethylamine)-dihydroborate bis(trifluoromethylsulfonyl)amide (NTf2(-)) ionic liquids (ILs). Mechanistic details of the electroreduction have been probed by dc and Fourier transformed ac voltammetry, simulation of the voltammetry, bulk electrolysis, and EPR spectroscopy. The first one-electron reduction induces fast cis to trans isomerization in CH3CN and ILs, most likely occurring via disproportionation of cis-stilbene radical anions and fast transformation of the cis-dianion to the trans-configuration. The second reduction process is chemically irreversible in CH3CN due to protonation of the dianion but chemically reversible in highly aprotic ILs under high cis-stilbene concentration conditions. Increase of the (n-Bu)4NPF6 supporting electrolyte concentration (0.01-1.0 M) in CH3CN induces substantial positive shifts in the potentials for reduction of cis-stilbene, consistent with strong ion pairing of the anion radical and dianion with (n-Bu)4N(+). However, protection by ion pairing against protonation of the stilbene dianions or electrochemically induced cis-trans-stilbene isomerization is not achieved. Differences in electrode kinetics and reversible potentials for cis-stilbene(0/•-) and trans-stilbene(0/•-) processes are less pronounced in the Pyrr1,4-NTf2 ionic liquid than in the molecular solvent acetonitrile.

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Photochemical and electrochemical Z–E isomerization of 1,4-dialkoxy-2,5-bis[2-(thien-2-yl)ethenyl]benzene stereoisomers

Cited by 2 publications

References 32 publications

Photophysical Properties and Photochemistry ofEE-,EZ-, andZZ-1,4-Dimethoxy-2,5-bis[2-(thien-2-yl)ethenyl] Benzene in Solution: Theory and Experiment

Photophysical Properties and Photochemistry ofEE-,EZ-, andZZ-1,4-Dimethoxy-2,5-bis[2-(thien-2-yl)ethenyl] Benzene in Solution: Theory and Experiment

Studies on the Nuances of the Electrochemically Induced Room Temperature Isomerization of cis-Stilbene in Acetonitrile and Ionic Liquids

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