• Effect of ring aza substitution on the luminescence of aromatic ketones. Luminescence of isomeric acetylpyridines

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      https://www.ias.ac.in/article/fulltext/jcsc/092/01/0047-0058

    • Keywords

       

      Isomeric acetylpyridines; absorption; emission; inductive effect; vibronic interaction; photochemical reaction; luminescence

    • Abstract

       

      The absorption and luminescence characteristics of 2-,3-and 4-acetyl-pyridines (ACP) and acetophenone have been examined in polar and nonpolar media at room temperature and low temperature (77K). All the ACP exhibit intense and structured phosphorescence emission of* character. Though the triplet yields of these ketones are very high, the phosphorescence quantum yield and lifetime of ACP decrease significantly in the order 4-ACP>3-ACP>2-ACP> acetophenone. The distinctive differences in the spectral properties and the luminescence characteristics of ACP from their phenylanalogue have been interpreted in terms of the perturbing influences of the inductive effect of the pyridinic nitrogen, the vibronic interaction between the* andππ* states and the photochemical reaction occurring from the lowest triplet state.

    • Author Affiliations

       

      S K Sarkar1 S K Ghoshal1 G S Kastha1

      1. Optics Department, Indian Association for the Cultivation of Science, Jadavpur, Calcutta - 700032, India
    • Dates

       
  • Journal of Chemical Sciences | News

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