COLLISIONAL ENERGY TRANSFER IN THE THREE-CHANNEL THERMAL DECOMPOSITION OF 1-CHLORO-2,2,3,3-TERTAFLUOROCYCLOBUTANE

Article abstract of DOI:10.1021/j100342a024

The three-channel thermal decomposition of 1-chloro-2,2,3,3-tetrafluorocyclobutane has been investigated over the temperature range 915-1255 K by using the technique of very low pressure pyrolysis (VLPP).The three individual channels are the elimination of hydrogen chloride, the formation of 1,1-difluoroethylene and 1-chloro-2,2-difluoroethylene.Extrapolated high-pressure rate coefficients (s^-1) for the separate channels are 1E(13.2+/-0.3)exp(-271 +/- 8 kJ mol^-1/RT), 1E(15.3+/-0.3)exp(-287 +/- 8 kJ mol^-1/RT), and 1E(15.3 +/- 0.3)exp(-287 +/- 8 kJ mol^-1/RT), respectively, which are consistent with previous studies of related compounds and the predicted effects of chloro and fluoro substitution.With the technique of pressure-dependent VLPP, the average downward energy transferred from the reactant to the bath gas upon collision, (ΔE_down), has been obtained for the bath gases Ne, Kr, CO2, CH4, CF4, C2H4, and CH2CF2 at ca. 1048 K.The values (cm^-1) are 445 (Ne), ca. 500 (Kr), 735 (CO2), 665 (CH4), 1370 (CF4), 920 (C2H4), and 1190 (CH2CF2).The data are found to be insensitive to the choice of the energy-transfer probability function (four functions were tested).A comparison is made between the (ΔE_down) values for the bath gases CF4 and CH2CF2 with those for CH4 and C2H4, respectively, with a discussion of the effect of resonance.