Proton Transfer Tautomerism in the Excited State of Indazole in Acetic Acid: Tautomerization via Double Proton Switching

Article abstract of DOI:10.1021/j100249a005

It is shown that the S₁ state of 1H-indazole in acetic acid undergoes double proton transfer along the hydrogen bonds in the indazole-acetic acid complex.The proton transfer converts 1H-indazole into 2H-indazole.The rate of proton transfer is estimated to be 2.7x10⁹ s^1- from transient fluorescence measurements.