An ab initio study on the photoisomerization in 2-styrylpyridine

Area of Science:

• Photochemistry
• Theoretical Chemistry
• Computational Chemistry

Background:

• 2-Styrylpyridine (2-SP) is a molecule with potential applications in photochemistry.
• Understanding its photoinduced processes is crucial for designing new materials and reactions.

Purpose of the Study:

• To investigate the photoinduced processes in 2-styrylpyridine using theoretical methods.
• To map the potential energy surfaces and identify key reaction pathways, including isomerization and cyclization.

Main Methods:

• Second-order Møller-Plesset (MP2) and algebraic diagrammatic construction to second-order (ADC(2)) methods with cc-pVTZ basis set for conformer geometries and energies.
• Complete active space self-consistent field (CASSCF) method for locating minimum-energy conical intersection (MECI) geometries between S0 and S1 states.

Main Results:

• Identified twisted-pyramidalized MECI points for trans-cis isomerization.
• Located S1/S0 cooperating-ring and cyclized-ring MECI structures on cis-2-styrylpyridine cyclization pathways.
• Determined that most MECI points are accessible from Franck-Condon points, except for specific twisted and cyclized structures.

Conclusions:

• The study elucidates the accessible reaction pathways for photoinduced cis-trans isomerization and cyclization in 2-styrylpyridine.
• Findings provide insights into the photochemical reactivity of 2-styrylpyridine, guiding future experimental and theoretical investigations.