Journal of Physical Chemistry A, Vol.120, No.51, 10088-10095, 2016
Ultrafast Photodissociation Dynamics of Highly Excited Iodobenzene on the C Band
The photodissociation dynamics of highly excited iodobenzene from the C band absorption has been studied by femtosecond time-resolved ion yields techniques. Detailed photodissociation routes are discussed with the aid of high-level, spin-orbit resolved ab initio calculations of 1D potential energy curves. Upon 200 nm excitation within the C band, iodobenzene molecules on 7B(2) and 7B(1) states decay to 7A(1) and 8B(2) states through internal conversion in 75 fs, with electronic energy converted into high vibrational energy of 7A(1) and 8B(2) states. Subsequently, 7A(1) and 8B(2) states decay through internal vibrational energy redistribution in 540 fs, accompanied by the excited C-I mode and the resulting cleavage of the C-I bond. The overall time for the reaction starting from the phenyl-type modes and ending in final C-I fragmentation for I(P-2(3/2)) production is 1.2 ps.