Reactions between N2+ and N2

The N3+ Reactivity in Ionized Gases Containing Sulfur, Nitrogen, and Carbon Oxides

The N(3)(+) reactivity with SO(2), N(2)O, CO(2), and CO is studied by mass spectrometric techniques under a wide range of pressures from 10(-7) to 10(-4) Torr. The kinetics, reaction mechanism, and role of vibrationally excited ions are investigated by experimental and theoretical methods. Key distinguishing features of the N(3) (+) reactivity are evidenced by comparison to N(+) and N(2)(+) ions, which mainly undergo charge-exchange reactions. The N(+) transfer to SO(2) prompts formation of NO(+) ions and neutral oxides NO and SO. The N(+) transfer to N(2)O also leads to NO(+) ions by a process not allowed by spin conservation rules. In both cases no reaction intermediate is detected, whereas CO(2) and CO are captured to form the very stable NCO(2) (+) and NCO(+) ions. NCO(2)(+) ions are characterized for the first time as strongly bound triplet ions of NOCO and ONCO connectivity. DFT and CCSD(T) computations have been carried out to investigate the structural and energetic features of the NCO(2) (+) species and their formation process.

N+ charge transfer and N+2 dissociation in N2 at swarm energies

This paper reports a drift-tube-mass-spectrometer measurement of the relative abundances of N+ and N+2 in pure nitrogen, over a ratio of electric field to gas density, E/N, from 800 to 7200 Td [1 townsend (Td)=10(-17) V cm(2)]. A proposed charge transfer dissociation scheme between the above two ions and N2 allowed us to obtain spatial rate coefficients for charge transfer and dissociation over the E/N range 800-2800 Td. Using previously measured cross sections for the above processes, and assuming a Maxwellian distribution of ion velocities, we calculated the reaction coefficients, which were found to be in good agreement with our measured values. In particular, the present results support the trend toward fairly high charge transfer cross section values for N+ energies above 10 eV. In the overlap range between 2.4 and 7.2 kTd, our concentration ratio [N(+)/N(+)(2)] is about five times smaller than that measured previously from a diffuse Townsend discharge in which electron impact is involved in addition to N+2 collisional dissociation with N2, but has the same trend. Thus it seems that, besides N+2 dissociation by electron impact, collisional dissociation becomes important at elevated values of E/N. In connection with previous discharge work in nitrogen, the present study may help explain the enhanced cathode yields observed.