Velocity map imaging and REMPI study of the photodissociation of CH 3SCH 3 from the first absorption band

Abstract

The photodissociation of dimethyl sulfide (CH 3SCH 3) at 229 nm has been studied employing a combination of velocity map imaging and time-of-flight resonance-enhanced multiphoton ionization techniques to detect the CH 3 products. Translational energy and recoil angle distributions as well as rotational state populations have been determined for the CH 3 photofragments formed in the ground vibrational state. The electronic excitation of CH 3SCH 3 to the first absorption band is found to produce fast CH 3S+CH 3 ( v=0) recoiling products with a negative spatial anisotropy parameter of β=−0.85±0.05. The CH 3 ( v=0) products are rotationally cold, the rotational distribution peaking at N′′=3–4.