Lee Hyeran, Berezin Mikhail Y, Henary Maged, Strekowski Lucjan, Achilefu Samuel
Department of Radiology, Washington University, St Louis, MO 63110, U.S.A. ; Tel: 314-362-8599; E-mail:
J Photochem Photobiol A Chem. 2008 Dec 15;200(2-3):438-444. doi: 10.1016/j.jphotochem.2008.09.008.
Structurally diverse near-infrared (NIR) absorbing polymethine dyes were prepared and their fluorescence lifetimes (FLT) were evaluated in relation to their structural features. Comparative FLT analysis based on the modification of methine chain length and heterocyclic system showed that indolium or benz[e]indolium heptamethine dyes exhibited longer FLT than the benz[c,d]indolium trimethine dye. Modification of heterocyclic system alone with an intact chain length showed that indolium-based heptamethine dyes showed approximately 30% longer FLT than the benz[e]indolium-based dyes. In general, the FLT of polymethine dyes increased from polar to non-polar solvents. In addition, correlation study between the theoretical and the experimental FLT for indocyanine green (ICG) suggests that the lack of structural rigidity for these cyanine dyes is primarily responsible for the loss of the excited state energy via non-radiative pathway.
制备了结构多样的近红外（NIR）吸收聚甲炔染料，并根据其结构特征评估了它们的荧光寿命（FLT）。基于次甲基链长度和杂环系统修饰的FLT比较分析表明，吲哚鎓或苯并[e]吲哚鎓七甲川染料的FLT比苯并[c,d]吲哚鎓三甲川染料更长。在链长度不变的情况下仅对杂环系统进行修饰表明，基于吲哚鎓的七甲川染料的FLT比基于苯并[e]吲哚鎓的染料长约30%。一般来说，聚甲炔染料的FLT从极性溶剂到非极性溶剂会增加。此外，吲哚菁绿（ICG）的理论和实验FLT之间的相关性研究表明，这些花菁染料缺乏结构刚性主要是通过非辐射途径导致激发态能量损失的原因。
