Structure and photophysics of deazabipyridyls. Excited internally hydrogen-bonded systems with one proton transfer reaction site

Abstract

Two deazabipyridyls, 2-(2-hydroxyphenyl)pyridin-3-ol 1 and 2-(2-pyridyl)phenol 2, are the objects of X-ray and spectroscopic studies. Their syntheses, crystal structures and photophysics in comparison with [2,2′-bipyridyl]-3,3′-diol and [2,2′-bipyridyl]-3-ol 3 are described. The influence of the molecular structure on the efficiency of the proton-transfer reaction in the S₁ state is discussed. The experimental data are compared with semiempirical quantum chemical calculations.