Gas-phase binding energies and spectroscopic properties of nitrosyl(1+) charge-transfer complexes

Gas-phase NO + affinities

“…A larger uncertainty is introduced by taking ⌬GЊ 1 Х ⌬HЊ 1 , as required to convert single-temperature equilibrium data into a BE scale, according to a practice largely adopted in the evaluation of gas-phase PAs (22). As discussed in the related study of NO 2 ϩ complexes (23), we conservatively estimate the uncertainty introduced by the above approximation to be generally below 0.8 kcal⅐mol Ϫ1 , although there are reasons to believe that ⌬GЊ changes closely approximate ⌬HЊ changes in NO ϩ transfer equilibria (21). By combining the experimental scatter of the data with the uncertainty arising from taking ⌬GЊ Х ⌬HЊ, we estimate that the overall internal consistency of the scale is of the order of Ϯ 1.2 kcal⅐mol Ϫ1 .…”

Quantum-chemical study of nitrosonium complexes of monocyclic aromatic compounds

“…It is presumed that the nitrosonium-cation and some molecules being its sources take part in the processes of neurotoxic and neuroprotective actions of nitrogen oxide [17], and also are involved in the reactions resulting in DNA cross-linking [18]. Inasmuch as the experimental measurement of the aromatic compounds affi nity to the nitrosonium-cation (A NO +) is a complicated problem [1,19,20] it is interesting to apply the quantum-chemical methods to the calculation of A NO + values.The goal of this study is the theoretical investigation of the effect of structural factors on the complex formation of NO + cation with monocyclic aromatic compounds and establishing the features of the structure of the nitrosonium complexes.The following aromatic compounds we have chosen as the objects of the study: benzene (Ia) and its derivatives C 6 H 5 X Ib-Io, and also compounds II-VII. The choice of the objects of the study took into consideration the existence of the experimental data on the affi nity of the aromatic compounds to the NO + cation and the presence of spectral and XRD data supporting the formation of the nitrosonium complexes [1,[4][5][6].…”

“…It is presumed that the nitrosonium-cation and some molecules being its sources take part in the processes of neurotoxic and neuroprotective actions of nitrogen oxide [17], and also are involved in the reactions resulting in DNA cross-linking [18]. Inasmuch as the experimental measurement of the aromatic compounds affi nity to the nitrosonium-cation (A NO +) is a complicated problem [1,19,20] it is interesting to apply the quantum-chemical methods to the calculation of A NO + values.…”

“…1 Note that the experimentally measured A NO + values essentially depend on the reference, and the differences exceed 60 kJ mol −1 [19,20]. The analysis of this situation led to conclusion [20] that the error in the A NO + values determined in [20] might attain ±8 kJ mol −1 .…”

“…and affi nity of compounds I-VII to nitrosonium cation (A NO +, kJ mol −1 ) a NO + values were calculated with accounting for ZPE. b A NO + values given in parentheses are calculated from the data[19], therewith the A NO + value for benzene was taken equal 131.0 kJ mol −1…”