Relaxation of DF( v = 1) by various polyatomic molecules

By means of the technique of laser‐induced fluorescence, the room‐temperature vibrational relaxation of DF( v = 1) has been studied in the presence of several polyatomic chaperones. The rate coefficients obtained [in units of (μ;sec·torr) −1 ] are CH 4 , 0.22; C 2 H 6 , 0.61; C 4 H 10 , 1.26; C 2 H 2 , 4.0 × 10 −2 ; C 2 H 2 F 2 , 1.86 × 10 −2 ; C 2 H 4 , 0.175; CH 3 F, 0.36; CF 3 H, 1.95 × 10 −2 ; CF 4 , 1.0 × 10 −3 ; CBrF 3 , 5.6 × 10 −4 ; NF 3 , 5.1 × 10 −4 ; SO 2 , 1.27 × 10 −2 ; and BF 3 , 7.1 × 10 −3 . Results are also reported for vibrational relaxation rate coefficients for HF( v = 1) in the presence of the following chaperones: CH 4 , 2.6 × 10 −2 ; C 2 H 6 , 5.9 × 10 −2 ; C 3 H 8 , 8.4 × 10 −2 ; and C 4 H 10 , 0.128. A comparison of DF and HF results indicates that for deactivation by C n H n +2 , rate coefficients for DF are approximately an order of magnitude larger than for HF. The deactivation rate coefficient of DF( v = 1) by CH 4 was found to decrease with increasing temperature between 300 and 740°K.