Abstract: In this work, we have measured the second-order rate constants of the reactions O(~3P)+CS_2 and N(~4S)+CS_2 over temperature range 293-500 K using discharge flow-chemiluminescence method. The results obtained are as follows: k_1=(8.44_(-0.61)~(+0.66))×10~(-11)exp ((-2.1±0. 1)×4.184 kJ·mol~(-1)/RT) cm~3·molec~(-1). s~(-1) (for O(~3P) + CS_2) and k_2=(3.09_(0.80)~(+1.08))×10~(-11) exp((-1.87±0.22)×4.184 kJ·mol~(-1)/RT)cm~3·molec~(-1)·s~(-1)(for N(~4S)+CS_2), respectively. The value of k_1 is in good agreement with literature results. With our best knowledge, no value of k_2 has been reported. In addition, we have calculated the structural parameters and energies of the intermediates NCS_2 and NSCS of the reaction N(~4S)+CS_2 by using approximate quantum chemistry theory. The minimum potential energy curves via reaction coordinates have also been calculated. A discussion of the reaction mechanism is presented.

Key words: Kinetics, Oxygen atom, Nitrogen atom, CS₂ molecule