Predicted thermochemistry and unimolecular kinetics of nitrous sulfide

Abstract

The geometry of N2S was obtained at the CCSD(T)/aug-cc-pV(T + d)Z level of theory and energies with coupled-cluster single double triple (CCSD(T)) and basis sets up to aug-cc-pV(6 + d)Z. After correction for anharmonic zero-point energy, core-valence correlation, correlation up to CCSDT(Q) and relativistic effects, D0 for the N–S bond is estimated as 71.9 kJ mol−1, and the corresponding thermochemistry for N2S is ${\rm \Delta }_{\rm f} {\rm H}_0^ \circ = 205.4\,{\rm kJ}\,{\rm mol}^{ - 1}$ΔfH0∘=205.4 kJ mol −1 and ${\rm \Delta }_{\rm f} {\rm H}_{298}^ \circ = 202.6\,{\rm kJ}\,{\rm mol}^{ - 1}$ΔfH298∘=202.6 kJ mol −1 with an uncertainty of ±2.5 kJ mol−1. Using CCSD(T)/aug-cc-pV(T + d) theory the minimum energy crossing point between singlet and triplet potential energy curves is found at r(N–N) ≈ 1.105 Å and r(N–S) ≈ 2.232 Å, with an energy 72 kJ mol−1 above N2 + S(3P). Application of Troe's unimolecular formalism yields the low-pressure-limiting rate constant for dissociation of N2S k0 = 7.6 × 10−10 exp(−126 kJ mol−1/RT) cm3 molecule−1 s−1 over 700–2000 K. The estimated uncertainty is a factor of 4 arising from unknown parameters for energy transfer between N2S and Ar or N2 bath gas. The thermochemistry and kinetics were included in a mechanism for CO/H2/H2S oxidation and the conclusion is that little NO is produced via subsequent chemistry of NNS.

Low-damaged p-type doping of MoS2 using direct nitrogen plasma modulated by toroidal-magnetic-field

“…Apart from the substitutional process, gas NS and N 2 S could be produced owing to the combination of N/N 2 atoms with S atoms, which can lead to severe chemical etching [24]. To explain the chemical etching, the courses of reaction and the formation energies of S vacancies and gas NS (N 2 S) generating by the N (N 2 ) are defined as…”

Légkörkémiai fontosságú kisebb gyökök és molekulák ab initio termokémiája

“…A fenti módon bevezetett atomi képződéshőt több tanulmány [184][185][186] is felhasználta referencia minőségű adatok számításához.…”