Tautomerism and aromaticity of the 1-(pyridin-2-yl)-3-(quinolin-2-yl)acetone molecule

Proton transfer on heterocyclic nitrogen atom is connected with decreasing the aromaticity of these rings. Additionally the aromaticity of quasi-rings also deserves on attention. HOMA values show that as a result of proton transfer, they turn from the completely antiaromatic into more aromatic than heterocyclic rings.