Substituent Effects on Dynamics at Conical Intersections: α,β-Enones

Content Provider	Semantic Scholar
Author	Lee, Aaron M. Coe, Jeffrey D. Ullrich, Susanne Cheng, B.-M. Zgierski, Marek Z. Chen, I-C. Martínez, Todd J. Stolow, A.
Copyright Year	2007
Abstract	Femtosecond time-resolved photoelectron spectroscopy and high-level theoretical calculations were used to study the effects of methyl substitution on the electronic dynamics of the α,β-enones acrolein (2-propenal), crotonaldehyde (2-butenal), methylvinylketone (3-buten-2-one), and methacrolein (2-methyl-2-propenal) following excitation to the S2(ππ*) state at 209 and 200 nm. We determine that following excitation the molecules move rapidly away from the Franck−Condon region, reaching a conical intersection promoting relaxation to the S1(nπ*) state. Once on the S1 surface, the trajectories access another conical intersection, leading them to the ground state. Only small variations between molecules are seen in their S2 decay times. However, the position of methyl group substitution greatly affects the relaxation rate from the S1 surface and the branching ratios to the products. Ab initio calculations used to compare the geometries, energies, and topographies of the S1/S0 conical intersections of the molecu...
Starting Page	11948
Ending Page	11960
Page Count	13
File Format	PDF HTM / HTML
DOI	10.1021/jp074622j
Alternate Webpage(s)	http://faculty.chem.queensu.ca/people/faculty/stolow/publications/pdf_publications/2007/acrolein_jpca2007.pdf
Alternate Webpage(s)	https://doi.org/10.1021/jp074622j
Volume Number	111
Language	English
Access Restriction	Open
Content Type	Text
Resource Type	Article