TY - JOUR
T1 - Quantum chemical analysis of para-substitution effects on the electronic structure of phenylnitrenium ions in the gas phase and aqueous solution
AU - Sullivan, Michael B.
AU - Brown, Kenneth
AU - Cramer, Christopher J.
AU - Truhlar, Donald G.
PY - 1998/11/18
Y1 - 1998/11/18
N2 - Ab initio calculations for para-substituted phenylnitrenium ions predict larger singlet-triplet splittings, shorter singlet C-N+ bond lengths, and higher singlet aromatic ring stretching frequencies for substituents with greater electron-donating character. Trends in these properties correlate linearly with para-substituent constants σR+, indicating that phehylnitrenium ions closely resemble other electron-deficient aromatic systems where resonance interactions with substituents are dominant. Sensitivity to substitution is large as judged by the slope of the correlating line for aqueous singlet-triplet splittings, p = 6.4. For 13 of 15 substituted cases, aqueous solvation preferentially stabilizes the singlet state by 0.9 to 4.4 kcal/mol; for the p-CO2H and p-CF3 cases, the triplet state is better solvated by less than 1 kcal/mol.
AB - Ab initio calculations for para-substituted phenylnitrenium ions predict larger singlet-triplet splittings, shorter singlet C-N+ bond lengths, and higher singlet aromatic ring stretching frequencies for substituents with greater electron-donating character. Trends in these properties correlate linearly with para-substituent constants σR+, indicating that phehylnitrenium ions closely resemble other electron-deficient aromatic systems where resonance interactions with substituents are dominant. Sensitivity to substitution is large as judged by the slope of the correlating line for aqueous singlet-triplet splittings, p = 6.4. For 13 of 15 substituted cases, aqueous solvation preferentially stabilizes the singlet state by 0.9 to 4.4 kcal/mol; for the p-CO2H and p-CF3 cases, the triplet state is better solvated by less than 1 kcal/mol.
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U2 - 10.1021/ja982542a
DO - 10.1021/ja982542a
M3 - Article
AN - SCOPUS:0032545009
SN - 0002-7863
VL - 120
SP - 11778
EP - 11783
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
IS - 45
ER -