THE MEASUREMENTS OF QUENCHING RATE CONSTA NTS OF ELECTRONICALLY EXCITED-STATE CH(C-2-SIGMA(+)) RADICAL

The rate constants for quenching of CH(C-2 Sigma(+),nu' = 0) by O-2, N -2, n-C5H12,n-C6H14 and n-C7H16 molecules were measured at room temper ature, CH(C-2 Sigma(+)) was produced by 266 nm laser photolysis of CHB r3 and the total fluorescence intensity of CH(C-->X) at (314.8 +/- 1) nm was then monitored using a fast digital storage oscilloscope couple d with a microcomputer. The rate constants (k) for the total removal o f CH(C) are compared with those of CH(X,A,B) states, and show to be k( X) > k(B) and k(C) for alkane quenchers, and the tendency of quenching rate constants for CH(C) is similar to those for CH(X,A,B) showing th e increase with increasing the number of C-H bonds in alkane molecules , The results indicate that the quenching of CH(A,B,C) is probably the entrance-channel controlled process and the chemical reaction might p lay an important role in collisional quenching of CH(A,B,C).