Production of nitrogen monosulfide(B2.PI.) from the sulfur(3P) + azide(X2.PI.) reaction

Abstract

A discharge flow apparatus was used to study the chemiluminescence of NS(B2II) resulting from the S(3P) + 3( 2 ) reaction. Ground-state sulfur atoms and azide radicals were produced by the reaction of excess fluorine atoms with H2S and HN3, respectively. The S + N3 reaction produces 8( 2 ) chemiluminescence in the region from 290 to 520 nm with an NS(B2n-* 2 ) photon yield of 0.06%. The 8( 2 ) branching fraction is viewed in terms of the many reactive surfaces present in this reaction. A spectral simulation code was written to obtain the vibrational populations and rotational temperatures of NS(B). The steady-state vibrational population revealed an inverted distribution with N""2 > N"m1. A bimodal rotational distribution is thought to occur with the initial rotational envelope approximated by an effective temperature of 1200 K.

Rates of reactions of azide radical with fluorine, chlorine, bromine, and hydrogen atoms

“…F atoms were produced in a side arm upstream in a microwave discharge through CF4 or F2, diluted in Ar. A second atom source (Cl2, H2, or Br2) was added downstream through the outer annulus of the sliding injector, such that a portion of the F atom stream was converted to Cl, H, or Br atoms via one of the following reactions: F + Cl2 -* C1F + Cl (7) F + H2 -HF + H ( 8)…”

“…In every case, however, chemiluminescence from these atom/N3 reactions is consistent with the higher energy available only from N3; indeed, the states observed were often thermodynamically inaccessible 0022-3654/92/2096-4907S03.00/0 from atom + NF(a) reactions. [5][6][7]9 In the experiments described in this paper, we have sought to resolve the issue of the F + N3 rate constant. Fortunately for this purpose, the method of laser-induced fluorescence (LIF) detection of N3 has been recently developed by Setser and co-workers13 and by Marinelli.14 This method allows direct observation of N3 and hence of its time dependence in the F + HN3/N3 system.…”

Chemical Kinetics of the Azide Radical: Rate Constants for Reactions with Cl, NO, NO2, O2, CO, CO2, Cl2, and C3H6

“…The reactions of azide radicals have been previously studied with a variety of atomic partners, including F, Cl, Br, S, N, C, O, P, and As. ,,− ,,− All of these reactants give some electronically excited products; however, only the reactions with halogen atoms 7,8 and nitrogen atoms 28,29 have high branching fractions for producing electronically excited products. A large body of work has used the reaction of N 3 with F atoms as the chemical source for NF(a 1 Δ). ,,− Currently, the focus has shifted to the reaction of N 3 with Cl atoms, since this reaction produces a high yield of electronically excited singlet NCl(a 1 Δ) molecules with perhaps some NCl(X 3 Σ - ). ,− ,, A wide discrepancy exists in the values of k 3 reported by different laboratories.…”

“…The reactions of azide radicals have been previously studied with a variety of atomic partners, including F, Cl, Br, S, N, C, O, P, and As. 7,8,[10][11][12][13][14][15]20,[28][29][30][31][32][33][34][35] All of these reactants give some electronically excited products; however, only the reactions with halogen atoms 7,8 and nitrogen atoms 28,29 have high branching fractions for producing electronically excited products. A large body of work has used the reaction of N 3 with F atoms as the chemical source for NF(a 1 ∆).…”