Photoinduced dissociation of cyclobutane thymine dimer studied by semiclassical dynamics simulation.
Photoinduced dissociation of the thymine dimer is studied in a semiclassical dynamics simulation. The simulation follows excitation of an isolated thymine dimer by a 25 fs fwhm laser pulse, and finds that dissociation proceeds via an asynchronously concerted mechanism, in which the C(5)-C(5)' bond breaks soon after application of the laser pulse, followed by cleavage of the C(6)-C(6)' bond. The dissociation results in two thymine monomers, one in an electronically excited state and the other in the ground state. The former decays to the electronic ground state through an avoided crossing induced by deformation of the pyrimidine ring at the C(5)' and C(6)' sites.
Dou
Yusheng
Y
Institute of Computational Chemistry and Molecular Simulation, Chongqing University of Posts and Telecommunications, Chongqing 400065, PR China. Yusheng.Dou@nicholls.edu
Xiong
Shanshan
S
Wu
Weifeng
W
Yuan
Shuai
S
Tang
Hong
H
D007834:Lasers; D056004:Molecular Dynamics Simulation; D010782:Photolysis; D011740:Pyrimidine Dimers / Q000737:chemistry*; D011789:Quantum Theory; D013816:Thermodynamics; D013997:Time Factors
D011740:Pyrimidine Dimers