Ultrafast Photodissociation Dynamics of $n$-Butyl Iodide in the A-Band

Abstract

Ultrafast photodissociation dynamics of n-butyl iodide in the A-band has been studied by femtosecond time-resolved mass spectroscopy coupled with ion imaging. The time constant of n-C 4 H 9 I in the A-band with one photon excitation at ∼267 nm is measured to be ∼(58±6) fs. The ion images of I ( 2 P 3/2 ) and I * ( 2 P 1/2 ) at ∼267 nm and ∼274 nm are obtained and analyzed to yield corresponding speed and angular distributions. The dependences of dissociation mechanism on excitation wavelength and the size of the alkyl radical are discussed.