Electron density distribution in heterocyclic systems with two adjacent nitrogen atoms
Dipole moments found are compared with those calculated vectoran ially. Bis(3, 5-dimethylpyrazol-4-yl) has a constant dipole moment, which indicates inequality of nitrogen atoms in the pyrazole ring. Dipole moments of condensed pyrazolopyridines can be found by adding vectorially the dipole moments of pyridine and pyrazole. Involvement of a nitrogen atom and formation of two aromatic rings does not significantly alter the dipole moment of pyrazolo[2, 3-a]-pyridine as compared with pyrazole.