Inner-shell X-ray absorption spectra of the cationic series NH_y⁺ (y = 0–3)

Abstract

Determination of the electronic structure of mass-selected transient molecular ions which can be considered as building blocks of biomolecules.

Interplay of Open-Shell Spin-Coupling and Jahn–Teller Distortion in Benzene Radical Cation Probed by X-ray Spectroscopy

“…This is attributed to the different possible spin couplings of the three unpaired electronsin very simplistic terms, 2 (core) × 1 (ππ * ) versus 2 (core) × 3 (ππ * ) -yielding final doublet spin states of core-ππ * character. Analogous splittings have recently been observed in the N + 2 , CO + and NH + 3 cations; [59][60][61] they also bear conceptual similarities with the splitting observed in the 1s shake-up spectrum of neon. 62 In addition, JT relaxation lifts the degeneracy of the π * orbitals, further increasing the splitting.…”

Photoionization Cross Sections of Carbon-Like N+ near the K-Edge (390 eV - 440 eV)

“…The N 3+ ion yield data of Bari et al [11] in the 400 eV region are in reasonable agreement with the present data of Fig. 3(b) for both the main resonances energies and relative intensities.…”

“…3(b) for both the main resonances energies and relative intensities. However, resonance assignments suggested by Bari et al [11], based on their own GAMESS configuration interaction (CI) calculations and the previous work of Garabeih et al [8], differ to some extent from those provided by the detailed analyses of the present work. The more complete comparisons shown between the present absolute measurements (see Section 2) and the results of extended atomic structure calculations from two theoretical approaches lead us to believe that the revised analyses of the present work are conclusive.…”

“…Only a qualitative comparison of the N 3+ ion yield data by Bari et al [11] (their figure 3(b)) is feasible. It indicates a reasonable agreement between the resonance energies and intensity patterns observed in the two works .…”

“…1s photoionization of neutral nitrogen was investigated by Stolte et al [7] while Gharaibeh et al measured K-shell cross-sections in N + (carbon-like) [8] and N 2+ (B-like) [9], Al-Shorman et al investigated N 3+ and N 4+ [10]. Recently, ion yield spectra following x-ray absorption in the K threshold region of the N + , NH + , NH2 + and NH3 + species were obtained by Bari et al [11]. For N + , these authors measured the double-ionisation yield (N 3+ ) and provided resonance assignments based on both ab initio CI calculations using the General Atomic and Molecular Electronic Structure System (GAMESS) package [12] and the results of Ref.…”