The X-ray crystallographic structure of the title compound shows the short and long bond pattern expected for the quinonoid classical structure. The corresponding equilibrium structure, from ab initio SCF calculations with a double zeta basis set is in close agreement, with differences generally less than 0.02 Å. The 14N nuclear quadrupole coupling constants, obtained by level-crossing and cross relaxation NQR spectroscopy, are assigned from the calculated electric field gradients. These show that N 1 and N 2 have tensor elements similar to pyridine and pyrrole respectively. One of the tensor elements at N 1 lies relatively close to the NN bond direction, but the principal value is radial to the ring, a classical lone-pair situation. At N 2, the principal value lies in the out-of-plane direction, with the in-plane tensor element values calculated to lie well away from the bond axes. Attempts to solve the structure of the unmethylated compound, which is expected to consist of H-bonded dimers, have so far been unsuccessful; this failure may result from the presence of a disordered tautomeric mixture in the lattice. The equilibrium structure of the unmethylated molecule shows a very similar quadrupole coupling pattern to the 2-methyl derivative. Neither populations or field gradients are significantly affected by all-valence electron CI, for either molecule.