Flash photolysis of carbon suboxide: absolute rate constants for reactions of C( 3 P) and C( 1 D) with H 2 , N 2 , CO, NO, O 2 and CH 4

Abstract

The vacuum ultraviolet flash photolysis of C 3 O 2 in the 159.0 nm absorption band has been investigated. The major primary products are C( 1 S), C( 1 D), C( 3 P), and CO. The species C 2 and C 3 have also been observed but are of minor importance in the overall reaction scheme. A number of pressure independent reactions involving C( 3 P), C( 1 D), and C( 1 S) with CO, CH 4 , N 2 , NO, O 2 , and H 2 have been observed by means of the kinetic-spectroscopic method. The rate constants measured at room temperature are summarized here (cm 3 s -1 molecule -1 ): C( 3 P) + CH 4 → C 2 H 4 (?) k < 5 x 10 -15 (7) C( 1 D) + CH 4 → C 2 H 2 + H 2 k = 3.2 x 10 -11 (8) C( 1 D) + N 2 → C( 3 P) + N 2 k ≈ 2.5 x 10 -12 (10) C( 3 P) + NO → CN + O k = 1.1 x 10 -10 (12) C( 1 D) + NO → CN + O k = 9.2 x 10 -11 (13) C( 1 D) + H 2 → CH + H k = 4.15 x 10 -11 (18) C( 1 S) + H 2 → CH + H(?) k < 5 x 10 -12 (19) C( 3 P ) + O 2 → CO + O k = 3.3 x 10 -11 (20) C( 1 D) + O 2 → CO + O(?) k < 5 x 10 -12 (22) The pressure dependent reaction rates of C( 3 P) with N 2 , CO, and H 2 have been qualitatively measured and are discussed in detail.