Departamento de Química Física, Facultad de Farmacia, Universidad de Sevilla, Sevilla, Spain.
Photochem Photobiol. 2012 Mar-Apr;88(2):277-84. doi: 10.1111/j.1751-1097.2011.01056.x. Epub 2012 Jan 10.
This paper reports a comprehensive photophysical study of the aggregation process of 1-azacarbazole, or α-carboline (9H-pyrido[2,3-b]indole), AC, in low polar aprotic solvents by using absorption, steady state and time-resolved fluorescence spectroscopic techniques. To ascertain the characteristics of the aggregation process we have studied the changes produced by the increase of the AC concentration and the decrease of the temperature on the absorption and fluorescence spectra of the AC monomer. Previously, to aid the interpretation of these results, the hydrogen bonding interactions of the AC monomer with pyridine, PY, and indole, IND, have been also analyzed. The results obtained from these studies reveal that, under our experimental conditions, AC does not form doubly hydrogen bonded cyclic dimers, (AC)(2), but singly hydrogen bonded open dimers, AC-AC, and open higher aggregates, (-AC-)(n). The formation of these species shifts to the red the absorption spectrum of the AC monomer and quenches its fluorescence.
本文通过吸收、稳态和时间分辨荧光光谱技术，报道了 1-氮杂咔唑（或 α-咔啉，9H-吡啶并[2,3-b]吲哚）AC 在低极性非质子溶剂中聚集过程的综合光物理研究。为了确定聚集过程的特征，我们研究了 AC 浓度增加和温度降低对 AC 单体吸收和荧光光谱的影响。此前，为了帮助解释这些结果，我们还分析了 AC 单体与吡啶（PY）和吲哚（IND）的氢键相互作用。这些研究的结果表明，在我们的实验条件下，AC 不会形成双氢键环状二聚体（AC）(2)，而是形成单氢键开环二聚体 AC-AC 和开环更高聚集体（-AC-）(n)。这些物种的形成使 AC 单体的吸收光谱红移，并猝灭其荧光。
