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Updated: Jun 6, 2025

Determination of the Photoisomerization Quantum Yield of a Hydrazone Photoswitch
Published on: February 7, 2022
An ab initio study on the photoisomerization in 2-styrylpyridine
Derreck W Nongspung1, Aditya N Panda1
1Department of Chemistry, Indian Institute of Technology Guwahati, Guwahati, India. anp@iitg.ac.in.
Abstract:
We report results of a theoretical study on photoinduced processes in 2-styrylpyridine. The geometries and the relative energies of the possible conformers were investigated using the second-order Møller-Plesset (MP2) and algebraic diagrammatic construction to second-order (ADC(2)) methods and the cc-pVTZ basis set. The complete active space self consistent field (CASSCF) method is used for locating the minimum-energy conical intersection (MECI) geometries between the S0 and S1 states. In addition to the twisted-pyramidalized MECI points along the trans and cis isomerization pathways, S1/S0 cooperating-ring MECI and cyclized-ring MECI structures, lying on the cyclization pathways of cis-2-styrylpyridine, were also located. Except the twisted pyramidalized CI2 and cyclized Cyc-CI3, all the other MECI points are found to be accessible from either one or more Franck-Condon points. The possibilities for the cis-trans isomerization and cyclization processes are discussed along the image-dependent pair potential (IDPP) paths.
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