Kinetic studies of the reaction of atomic sulfur with acetylene

摘要: Abstract The rate constant for reaction of sulfur atoms with acetylene was measured. Laser flash photolysis CS2 precursor employed to generate ground-state S(3P) atoms, which were monitored time-resolved resonance fluorescence as they reacted C2H2 in a large excess Ar bath gas. Temperatures from 295 1015 and pressures 10 500 mbar investigated. A pressure-dependence observed at all temperatures, revealing that adduct formation is the dominant channel. necessary stability suggests H2CCS or possibly HCCSH are products high so spin-forbidden. fall-off curves may be represented broadening factor Fcent = 0.6, low high-pressure limiting constants k0 = 1.0 × 10−18 (T/K)−3.55 exp(−1990 K/T) cm6 molecule−2 s−1 k∞ = 2.1 × 10−11 exp(−11.2 kJ mol−1/RT) cm3 molecule−1 s−1, respectively. An entrance barrier recombination about 10 kJ mol−1 proposed arise where singlet triplet potential energy cross.