Time-Resolved Photoelectron Studies of Thiophene and 2,5-Dimethylthiophene was written by Schalk, O.;Larsen, M. A. B.;Skov, A. B.;Liisberg, M. B.;Geng, T.;Soelling, T. I.;Thomas, R. D.. And the article was included in Journal of Physical Chemistry A in 2018.Quality Control of 2,5-Dimethylthiophene The following contents are mentioned in the article:
The photoinduced dynamics of thiophene and 2,5-dimethylthiophene (2,5-DMT) were investigated upon excitation at 200 and 255 nm (2,5-DMT only) using time-resolved photoelectron spectroscopy and compared with results from ab initio coupled cluster calculations For thiophene, depopulation of the initially excited B2(π3π4*) state to the lower-lying A1(π2π4*) state occurs within 25 ± 20 fs, with a subsequent bifurcation into a ring-puckering channel and a ring-opening channel with lifetimes of 80 ± 20 and 450 ± 50 fs, resp. For 2,5-DMT, the dynamics following excitation at 200 nm is described by a monoexponential decay with a time constant of 120 ± 20 fs, while that following excitation at 255 nm is best fit by a biexponential decay with time constants of 115 ± 20 fs and 15 ± 3 ps, resp. The fast signal observed after excitation of 2,5-DMT is assigned to the ring-opening channel, which is favored with respect to thiophene due to a lower excited-state barrier along the ring-opening coordinate and an increased inertia toward the ring-puckering channel. Coupled cluster calculations have been undertaken to compare the relaxation dynamics of thiophene to thiazole and isothiazole. For the latter two mols., we find a strong gradient along the ring-opening coordinate in the Franck-Condon region of the initially populated ππ* state and predict that ring-opening is the dominating relaxation channel after photoexcitation. We use the extracted information for a comparison of the thiophene dynamics with the light-induced processes observed in other five-membered heterocyclic mols. This study involved multiple reactions and reactants, such as 2,5-Dimethylthiophene (cas: 638-02-8Quality Control of 2,5-Dimethylthiophene).
2,5-Dimethylthiophene (cas: 638-02-8) belongs to benzothiophene derivatives. Benzothiophene is relatively a stable molecule. The core structure is a part of various pharmaceutical substances and natural products. The different substitution patterns in these heterocycles offer new opportunities for drug discovery and other applications in materials science.Quality Control of 2,5-Dimethylthiophene
Referemce:
Benzothiophene – Wikipedia,
Benzothiophene | C8H6S – PubChem