The syntheses and characterization of two new 1, 5-dimethyl-6-oxoverdazyl radicals bearing 2-pyridine and 4, 6-dimethyl-2-pyrimidine rings as substituents are described. The radical precursors, the corresponding 1, 2, 4, 5-tetrazanes, were prepared by condensation of the bis (1-methylhydrazide) of carbonic acid with the appropriate aromatic aldehyde. Oxidation of 3-(4, 6-dimethyl-2-pyrimidyl)-1, 5-dimethyl-1, 2, 4, 5-tetrazane 6-oxide (7) with sodium ...