Probing photon interaction with H₂O and D₂O

Abstract

Investigation of the valence state photoionization of water using vacuum ultraviolet and soft x-rays gives important information for spectroscopic analysis and studies of radiation loss and cell biology. In this article, the total and valence-shell photoionization cross sections of H2O and D2O, generating the states 2B1, 2A1 and 2B2, and their isotopic consequences are studied. The effect of bonding on valence state photoionization is also reported. The calculations were made using R-matrix theory for photon energies up to 40 eV. Electronic transitions below 20 eV were considered to account for the autoionizing Rydberg transitions. This is the first report to demonstrate the effect of bonding on valence state photoionization. For the isotopic partner (D2O), we observed a quantitative change in cross section. Comparisons are made with the previously available results and a reasonable agreement is found. The present study gives a comprehensive understanding of the photoionization of water, thus providing deep insight into different non-dissociative processes of the molecule in various environments.

Perturbative and nonperturbative photoionization of H2 and H2O using the molecular R<

“…Time-dependent calculations for H 2 O were performed in the single-active-electron approximation [54,55], strongfield approximation [56], recently using a time-dependent configuration-interaction singles approach [57], and the coupled-cluster method [17]; time-independent calculations have been performed using several approaches [58][59][60] including a recent GTO-only R-matrix one [61].…”

“…4. Orientation-averaged cross section for one-photon ionization of H 2 O calculated using the stationary (UKRmol+) and time-dependent (RMT) approaches, shown in comparison with experimental data from Katayama et al [63], Haddad and Samson [65] and photoabsorption calculations from Ruberti et al [66] and Tenorio et al [67] and photoionization calculation of Modak and Antony [61]. (a) Time-independent calculation with the larger model; both smoothed and raw UKRmol+ are shown.…”

“…Tan et al [72] Brion and Carnovale [69] Banna et al [68] Truesdale et al [73] Novikovskiy et al [60] Modak and Antony [61] Engin et al [70] FIG. 5.…”

“…The transitions to the three lowest states of H 2 O + are shown. Experimental data are from Tan et al [72], Truesdale et al [73], Brion and Carnovale [69], and Banna et al [68] and calculations are from Engin et al [70], Novikovskiy et al [60], and Modak and Antony [61]. The UKRmol+ results for energies smaller than 20 eV are heavily influenced by smoothing.…”

Easy Scale‐Up Synthesis of Mo8O26(C5H6N)4.H2O Hybrid with a Rectangular Prism Morphology and Its Application as an Efficient and Highly Recyclable Bi‐functional Catalyst for Knoevenagel Condensations

“…In this regard, some organic bases were immobilized on solid materials. The main solid materials were metal-organic frameworks, [28][29][30][31] molecular sieves, [32][33][34][35] and organic polymers. [36,37] Despite the advantages of these immobilized catalysts, they suffer from some drawbacks such as long reaction times, low yields, harsh reaction conditions, poor reusability of catalysts, and the use of toxic solvents.…”