SOLVATION AND NUCLEOPHILIC REACTIVITY OF 1,2,4-TRIAZOLATE ION IN ACETONITRILE-METHANOL MIXTURES

The 1,2,4-triazolate ion is a stronger hydrogen-bond accepting base th an fi-substituted 1,2;3-benzotriazolate ions. Partly because of this c haracteristic, the transition-state anion of the 1,2,4-triazolate ion reaction with ethyl iodide indicates the most significant hydrogen-bon d accepting basicity of a transition-state anion so far observed. The PM3 atomic charge on the nitrogen atom at the 4-position of the 1,2,4- triazolate ion and the average PM3 atomic charge on the nitrogen atom at the 1- and 3-positions of 5-substituted 1,2,3-benzotriazolate ions make the most significant contribution to the basicity of the relevant anion. The significant basicity for the transition-state anion has be en rationalized through an empirical correlation between the specific interaction enthalpy, Delta(t)H(SI)(AN-->MeOH), and atomic charge.