Photodissociation dynamics of vibrationally excited CH 2Cl 2 molecules

Department of Physics, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel
Chemical Physics Letters (Impact Factor: 2.15). 01/2003; 378(3):305-312. DOI: 10.1016/j.cplett.2003.07.012

ABSTRACT Photodissociation of dichloromethane excited to the second C–H stretch overtone was performed by ∼235 nm photons that also tagged the Cl 2P3/2 [Cl] and spin–orbit excited Cl 2P1/2 [Cl*] photofragments via resonantly enhanced multiphoton ionization. The measured time-of-flight profiles together with the determined Cl*/Cl branching ratio suggest fast dissociation and involvement of several upper states of different symmetries mixing via curve crossing to release both Cl and Cl*. The determined ratio is higher than that obtained previously in the direct, almost isoenergetic, photodissociation of CH2Cl2 implying higher non-adiabaticity for vibrationally excited than for vibrationless ground state molecules.

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