Chemical Reactions of NCL(A Sup 1 Delta): Generation and Removal

Abstract

Abstract : The Cl + N3 reaction was used to provide a source of NCl(a sup 1 delta) molecules in a room temperature flow reactor. The total quenching rate constants were measured for 40 molecular reagent species and for F, N, O and H atoms. In most cases, rate constants were obtained for both NF(a sup 1 delta) and NCl(a sup 1 delta) so that the data could be confirmed by comparison with earlier studies of NF(a sup 1 delta)). The quenching rate constants for NCl(a sup 1 delta) range from approx. 1 x 10(exp -15) to 4 x 10(exp -11) cu cm/molecule/s. Except for H, F, O, CH3Cl, HBr, HCl and HI, the rate constants for the NCl(a sup 1 delta) molecule are generally smaller than or comparable to those for NF(a sup 1 delta), and NCl(a sup 1 delta) is not especially reactive at 300 K. Small rate constants were obtained for common gases, such as H2, CO2 and CH4; the rate constants are larger for unsaturated hydrocarbons and they increase with the number of carbon atoms in the molecule. A correlation was found between the basicity of a series of amines and the magnitudes of quenching rate constants of NF(a sup 1 delta) and NCl(a sup 1 delta); the rate constants for NCl(a) were smaller than for NF(a) indicating a less acidic nature for NCl(a sup 1 delta).