Excited state properties of 2′-hydroxychalcone analogues functionalized with a diene moiety studied by steady state and laser flash photolysis

2'-Hydroxychalcone (HC) analogues 1 and 2 having a diene part tethering the phenyl and naphthyl chromophores, respectively, were prepared, and their photochemical and photophysical properties were studied. Fluorescence from these compounds was absent in solution and the solid state. Based on the results obtained upon steady state and laser flash photolyses, compound 2 was found to be substantially stable on photoirradiation without undergoing intersystem crossing to the triplet state whereas compounds 1 showed transient absorption due to the triplet tautomer. The deactivation processes in the excited states were discussed by considering energetic reaction diagrams for the corresponding tautomers and isomers. (C) 2017 Elsevier B.V. All rights reserved.