Kinetics of the self reaction of neopentyl radicals

The kinetics of the self reaction of neopentyl radicals ((CH3)3CCH2) was studied by laser photolysis/photoionization mass spectroscopy. Overall rate constants were obtained in direct real-time experiments in the temperature region 300–500 K and at bath gas densities of (3.00–12.0) × 1016 molecule cm−3. The observed overall neo-C5H11 + neo-C5H11 rate constants demonstrate negative temperature dependence: k1 = 3.1 × 10−12 exp(+506 K/T) cm3 molecule−1 s−1, with estimated uncertainty of 17% over the 300–500 K temperature range. Formation of C10H22 (mass to charge ratio of 142, interpreted as 2,2,5,5-tetramethylhexane) as the primary product of neopentyl self reaction was observed.