High temperature collisional energy transfer in highly vibrationally excited molecules: Isotope effects in tert-butyl chloride systems

✍ Scribed by Trevor C. Brown; Keith D. King; Robert G. Gilbert

• Publisher: John Wiley and Sons
• Year: 1984
• Tongue: English
• Weight: 781 KB
• Volume: 16
• Category: Article
• ISSN: 0538-8066
• DOI: 10.1002/kin.550161113

✦ Synopsis

The average downward collisional energy transfer () is obtained for highly vibrationally excited tert-butyl chloride, both undeuterated and per-deuterated, with Kr, N,, C02, and C2H4 bath gases, at ca. 760 K. Data are obtained using the technique of pressure-dependent very low-pressure pyrolysis. Reactant internal energies to which the data are sensitive are in the range 200-250 kJ mol-'. For C4H9C1, the values (cm-') are 255 (Kr), 265 (NZ), 440 (CO,), and 585 (C2H4), and for C4DgCl, 245 (N2), 370 (C02), and 540 (C2H4). The uncertainties in these values are ca. 20% (40% for Kr); the uncertainties in the deuteration ratios are 10-15%. The value for K r is in agreement with theoretical predictions of a biased random walk model for internal energy change in monatomic/substrate collisions. The effect of deuteration of is also in accord with that predicted by a modification of the theory. Extrapolated highpressure rate coefficients for the thermal decomposition of reactant are 1013 exp( -187 k J mol-'/RT) s-l (C4HgCl) and exp(-196 kJ mol-'/RT) s-' (C4D,C1), in accord with other studies and the expected isotope effect.