2-(2-羟基苯基)苯并噻唑的合成及其光学性质

Synthesis and Spectroscopy of 2-(2-Hydroxyphenyl)benzothiazole

2-(2-羟基苯基)苯并噻唑(BTZ)作为一类新型的有机电致发光材料,因其独特的性质而备受关注。它的光学性质已经得到了明确的阐述,由于其烯醇式激发态分子存在内质子转移的过程,从而表现出较大的斯托克斯位移。当BTZ存在于极性较小的溶剂中,有利于其酮式构型的稳定,使得激发态分子内质子转移(ESIPT)荧光强度增强,极性较大的溶剂会导致其正常荧光强度增加。此外,在羟基对位上接有吸电子基团时,苯环上电子云密度降低,同样有利于酮式构型的稳定,致使ESIPT荧光强度增强。BTZ可由多种方式合成,本文介绍了三条合成路线,实验室常利用水杨酸和邻氨基苯硫醇作为BTZ的合成原料,此法可一步得到产物,收率较高。2-(2-羟基苯基)苯并噻唑的衍生物,如锌、铍金属络合物,同样也表现出优良的光谱性质,是一类具有广阔开发前景的有机电致发光材料。

The 2-(2-hydroxyphenyl)benzothiazole (BTZ) is a new kind of electroluminescent materials, which has attracted much attention because of its unique properties. Its optical properties have been clearly described, and due to the process of proton transfer in enol excited molecules, the Stokes displacement is relatively large. The presence of BTZ in a less polar solvent was conducive to the stability of its ketone configuration, which enhanced the fluorescence intensity of the excited intramoleculproton transfer (ESIPT), while the normal fluorescence intensity was increased in a more polar solvent. In addition, when the hydroxyl para is attached with electron-withdrawing groups, the electron cloud density on the benzene ring decreases, which is also conducive to the stability of the ketone configuration, resulting in the enhanced fluorescence intensity of ESIPT. Three synthetic routes of BTZ are introduced in this paper. In laboratory, salicylic acid and o-amino- benzmercaptan are often used as raw materials to synthesize BTZ, which can get good yield in one step. Derivatives of 2-(2-hydroxyphenyl)benzothiazole, such as zinc and beryllium metal complexes, also exhibit excellent spectral properties and are a kind of electroluminescent materials with broad development prospects.