ATTEMPTED GENERATION AND STRUCTURE OF THE 4-(1,2,4-TRIAZOYL) CATION

4-(and 1-) Amino-1,2,4-triazoles have been treated with nitrosonium tetrafluoroborate or with isoamyl nitrite and acetic acid in the presence of mesitylene. The main product is 1,2,4-triazole, together with a small amount of the 1- and trace amounts of the 4-mesityl derivatives. Ab initio calculations of the putative 4-(1,2,4-triazoyl) cation show the electronic ground state to be a closed shell singlet (1)A(1) (4 pi e) (3), with a low-lying B-3(1) triplet (4) only 1 kcal/mol above it; the sigma-cation (1) is not a local minimum on the potential energy surface. Possible explanations of the results are proposed.