一类新型环金属配体——噁二唑衍生物的化学结构及其性能

Structure and Properties of Oxadiazole Derivatives as a New Class of Cyclometalating Ligands

合成了5个2,5-二芳基-1,3,4-噁二唑衍生物环金属配合物配体,其化学结构经1HNMR、IR和元素分析得到确证。利用紫外光谱、荧光光谱、差热分析(DSC)和循环伏安法测试技术分别研究了它们的光谱性能、热性能和电化学性能。结果表明,该类衍生物在二氯甲烷溶液中的最大紫外吸收波长在268～327nm范围,在二氯甲烷溶液和固体膜中的最大荧光发射波长分别在332～390nm和359～439nm范围;DSC分析结果表明,5个噁二唑衍生物的起始吸热峰位于120～328℃之间,其中对称结构的噁二唑衍生物显示了较高的熔融温度;由循环伏安图和相关计算结果表明,5个噁二唑衍生物的还原电位位于-1.03～-0.98V,其相应的最低非占有分子轨道能级(LUMO)在-3.71～-3.76eV之间。

Five 2,5-diaryl-1,3,4-oxadiazole derivatives used as a new class of cyclometlating ligands were synthsized. Their molecular structures were characterized by IR, ^I H NMR and element analysis. Furthermore, their spectroscopic, thermal and electrochemical properties were investigated by UV spectroscopy, fluorescence spectroscopy, differential scanning calorimetry（DSC） and cyclic voltammetry（ CV）, respectively. The results showed that the maximum UV absorption wavelengths of those 1,3,4-oxadiazole derivatives in dichloromethane were in the range of 268 - 327 nm, and their maximum photoluminescent wavelengths in dichloromethane and solid film were located at 332 - 390 nm and 359 - 439 nm, respectively. The 1,3,4-oxadiazole derivatives exhibit a first endothermal peak at 120 - 328 ℃ in the DSC heating process, and the symmetrical 1,3,4- oxadiazole derivatives display a higher melting temperature. The CV curves of those 1,3,4-oxadiazole derivatives indicate that the reductive potentials of the 1,3,4-oxadiazole derivatives are located at - 1.03 - - 0. 98 V, and their LUMO（ the lowest unoccoupied molecual orbit） energy levels are - 3.71 - - 3.76 eV.