Evidence for the onset of three-body decay in photodissociation of vibrationally excited CHFCl2

Excitation of C-H stretch overtones of CHFCl2 followed by similar to 235 nm photodissociation was applied to investigate the effect of internal parent excitation on the dynamics of two- and three-body photofragmentation. The similar to 235 nm photons also tagged ground Cl P-2(3/2) [Cl] and spin-orbi t excited Cl P-2(1/2) [Cl*] state photofragments, via (2 + 1) resonantly en hanced multiphoton ionization in a time-of-flight mass spectrometer, and mo nitored their time-of-arrival profiles. These profiles revealed the product velocities and angular distributions of Cl-35 and Cl-35* and suggest the c ontribution of three-body decay in photodissociation of CHFCl2 pre-excited with five quanta of C-H stretch. This is the first evidence for three-body decay in photodissociation of vibrationally excited molecules. (C) 2001 Ame rican Institute of Physics.