Department of Chemistry, Annamalai University, Annamalainagar, 608 002, Tamilnadu, India.
J Fluoresc. 2012 Jan;22(1):409-17. doi: 10.1007/s10895-011-0974-4. Epub 2011 Sep 23.
Novel imidazole derivatives were synthesized and its crystal structure has been studied by single crystal XRD analysis. The photophysical properties of these imidazole derivatives were studied in several solvents, which include a wide range of apolar, polar and protic media. The observed lower fluorescence quantum yield may be due to an increase in the non-radiative deactivation rate constant. This is attributed to a loss of planarity in the excited state provided by the non co-planarity of the aryl rings attached to C(2) and N(1) atoms of the imidazole ring. Such a geometrical change in the excited state leads to an important Stokes shift, reducing the reabsorption and reemission effects in the detected emission in highly concentrated solutions. The highest fluorescence quantum yield of the imidazole derivatives are observed in polar media.
新型咪唑衍生物被合成，并通过单晶 X 射线衍射分析研究了其晶体结构。研究了这些咪唑衍生物在几种溶剂中的光物理性质，包括广泛的非极性、极性和质子性介质。观察到的荧光量子产率较低可能是由于非辐射去活速率常数的增加。这归因于与咪唑环的 C(2)和 N(1)原子相连的芳环的非共面性导致激发态的平面性丧失。这种激发态的几何变化导致重要的斯托克斯位移，减少了高浓度溶液中检测到的发射中的再吸收和再发射效应。咪唑衍生物的荧光量子产率在极性介质中最高。
