Kinetic studies on state-state transitions for center dot CCl2(X(1)A(1), A(1)B(1),a(3)B(1)) radical and quenching of center dot CCl2(A(1)B(1) and a(3)B(1)) with methane and chloromethane

CCl2 free radicals were produced by d-c discharge of CCl4 (in Ar). The grou nd electronic state CCl2 radical was electronically excited to R-p(1) level of A(1)B(1) (0,4,0) state by laser exciting at 541.52 nm, Experimental que nching data of . CCl2(A(1)B(1) and a(3)B(1)) through methane and chlorometh ane were obtained by observing time resolved fluorescence from the excited . CCl2 transition, which showed a superposition of two exponential decay co mponents. The state-resolved rate constants k(q1), k(q2) and k(q3) Were fir st time estimated by analyzing and dealing with these data by using three-l evel energy model, which was put forward by us. In combining discharge with free jet-LIF the lifetimes of CCl2(A -->X) and (a -->X) transition were me asured being(0.83 +/- 0.03) mus and (3.12 +/- 0.25) mus, respectively.