Although never spectroscopically identified in the laboratory, hydrogenated nitrogen is thought to be an important species in combustion chemistry. The classical barrier height and exothermicity for the reaction are predicted by high level ab initio quantum mechanical methods [up to CCSDT(Q)]. Total energies are extrapolated to the complete basis set limit applying the focal point analysis. Zero-point vibrational energies are computed using fundamental (anharmonic) frequencies obtained from a quartic force field. Relativistic and diagonal Born–Oppenheimer corrections are also taken into account. The quantum mechanical barrier with these corrections is predicted to be and the reaction exothermicity to be . The importance of these parameters for the thermal decomposition process is discussed. The unimolecular rate constant for dissociation of the molecule and its lifetime are estimated by canonical transition-state theory and Rice–Ramsperger–Kassel–Marcus theory. The lifetime of the molecule is here estimated to be at room temperature. Our result is in marginal agreement with the latest experimental kinetic modeling studies , albeit consistent with the very rough experimental upper limit . For the dissociation reaction, kinetic isotope effects are investigated. Our analysis demonstrates that the molecule has a longer lifetime than the molecule. Thus, might be more readily identified experimentally. The ionization potential of the molecule is determined by analogous high level ab initio methods and focal point analysis. The adiabatic IP of is predicted to be , in only fair agreement with the experimental upper limit of 7.92 eV deduced from sychrothon-radiation-based photoionization mass spectrometry.
The barrier height, unimolecular rate constant, and lifetime for the dissociation of
Uğur Bozkaya, Justin M. Turney, Yukio Yamaguchi, Henry F. Schaefer; The barrier height, unimolecular rate constant, and lifetime for the dissociation of . J. Chem. Phys. 14 February 2010; 132 (6): 064308. https://doi.org/10.1063/1.3310285
Download citation file: