Rotational analysis of the nonthermal NO(A 2Σ+, v′=0) distribution observed in the N2(A 3Σ+u, v′=0)+NO(X 2Π, v″=0) energy transfer reaction

Abstract

A rapidly pumped discharge-flow reactor was constructed to characterize the N2(A 3Σ+u,v′)+NO(X 2Π, v″=0) energy transfer (ET) reaction. Emission spectra of the NO γ bands from the product NO A 2Σ state formed in the title reaction were collected with a 2.2 m vacuum-ultraviolet spectrograph monochromator utilizing both photographic and photoelectric techniques. The rotational structure of the γ bands resulting from the title reaction is resolved with a spectral resolution of Δλ∼0.1 Å. The product NO(A,v′) emission spectra were measured as a function of total pressure (∼0.8≤pTOTAL≤∼3.0 Torr) and initial N2(A,v′) population distribution at 298 K. The product NO(A,v′,N′) rotational distributions yield temperatures much higher than room temperature (>1600 K) and are discussed in detail. Vibrational level specific bimolecular rate constants kv′ ’s for the N2(A,4≤v′≤6)+NO reaction were measured using N2(B 3Πg–A 3Σ+u) laser-excited fluorescence detection with a fixed reaction time. The kv′ ’s are (9.5±1.0), (11.3±1.2), and (11.2±1.1)×10−11 cm3 molecule−1 s−1 for v′=4, 5, and 6, respectively. A comparison with previous measurements is presented.