Proton affinities of N-O anions and their protonated forms

The proton affinities (PA) of several N—O anions, namely the singly charged anions nitrite, peroxynitrite, nitrate and peroxynitrate and the doubly charged anions cis‐ and trans‐hyponitrite and oxyhyponitrite, were calculated to be 1413.8, 1440.5, 1348.5, 1414.7, 2065.2, 1987.4 and 1977.9 kJ mol−1, respectively. The PA of the corresponding conjugate acids were 780.3, 749.8, 746.0, 724.7, 1394.9, 1448.9 and 1340.7 kJ mol−1, respectively. The PA of cis‐ and trans‐hyponitric and oxyhyponitric acid were 906.7, 723.8 and 728.2 kJ mol−1, respectively. Comparison with the available experimental values for the acids indicates that the calculated values are good estimates of these important quantities. Copyright © 2002 John Wiley & Sons, Ltd.