Flash photolysis of carbon suboxide: absolute rate constants for reactions of C(3P) and C(1D) with H2, N2, CO, NO, O2 and CH4

The vacuum ultraviolet flash photolysis of C3O2 in the 159.0 nm absorption band has been investigated. The major primary products are C(1S), C(1D), C(3P), and CO. The species C2 and C3 have also been observed but are of minor importance in the overall reaction scheme. A number of pressure independent reactions involving C(3P), C(1D), and C(1S) with CO, CH4, N2, NO, O2, and H2 have been observed by means of the kinetic-spectroscopic method. The rate constants measured at room temperature are summarized here (cm3 s-1 molecule-1): C(3P) + CH4 → C2H4 (?) k < 5 x 10-15 (7) C(1D) + CH4 → C2H2 + H2k = 3.2 x 10-11 (8) C(1D) + N2 → C(3P) + N2k ≈ 2.5 x 10-12 (10) C(3P) + NO → CN + O k = 1.1 x 10-10 (12) C(1D) + NO → CN + O k = 9.2 x 10-11(13) C(1D) + H2 → CH + H k = 4.15 x 10-11 (18) C(1S) + H2 → CH + H(?) k < 5 x 10-12 (19) C(3P ) + O2 → CO + O k = 3.3 x 10-11 (20) C(1D) + O2 → CO + O(?) k < 5 x 10-12 (22) The pressure dependent reaction rates of C(3P) with N2, CO, and H2 have been qualitatively measured and are discussed in detail.