Gaenko Alexander V, Devarajan Ajitha, Tselinskii Igor V, Ryde Ulf
Department of Theoretical Chemistry, Chemical Center, Lund University, Sweden.
J Phys Chem A. 2006 Jun 29;110(25):7935-42. doi: 10.1021/jp060646z.
Electronic factors influencing the photoluminescence properties and rates of excited state intramolecular proton transfer (ESIPT) reaction of o-hydroxy derivatives of 2,5-diphenyl-1,3,4-oxadiazole have been studied. The potential of these molecules as emissive and electron transport materials in designing improved organic light emitting diodes (OLEDs) has been studied by analyzing possible reasons for the unusually high Stokes shifts and ESIPT reaction rates. Time-dependent density functional theory (TDDFT) methods have been used to calculate the ground and excited state properties of the phototautomers that are the ESIPT reaction products. We study the relative effect of electron-withdrawing substituents on the proton-acceptor moiety and predict that the lowest ESIPT rate (1.9 x 10(11) s(-1)) is achieved with a dimethylamino substituent and that the Stokes shifts are around 11 000 cm(-1) for all three derivatives.
研究了影响2,5-二苯基-1,3,4-恶二唑邻羟基衍生物的光致发光性质和激发态分子内质子转移（ESIPT）反应速率的电子因素。通过分析异常高的斯托克斯位移和ESIPT反应速率的可能原因，研究了这些分子在设计改进的有机发光二极管（OLED）中作为发光和电子传输材料的潜力。采用含时密度泛函理论（TDDFT）方法计算了作为ESIPT反应产物的光互变异构体的基态和激发态性质。我们研究了吸电子取代基对质子受体部分的相对影响，并预测二甲基氨基取代基的ESIPT速率最低（1.9×10¹¹ s⁻¹），且所有三种衍生物的斯托克斯位移均约为11000 cm⁻¹。
