Theoretical revealing regulated ESIPT behaviors by atomic electronegativity for quercetin fluorophore

•Excited state hydrogen bonding interactions of O1-H2···O3 and O5-H4···O3 should be enhanced in S1 state.•Low atomic electronegativity reveals excited state high kinetic dynamics and chemical activities.•ESIPT reaction should occur along with O5-H4···O3 hydrogen bond rather than the O1-H2···O3 one.•We elucidate specific atomic electronegativity dependent ESIPT mechanism.