含吡啶环的芳香醚-噁二唑类化合物的合成及其光谱研究

Synthesis of Aromatic Oxide-Oxadiazoles Containing Pyridine Ring and Study on Their Spectral Properties

为开发新的高强度的有机电致发光材料,用含烷氧基的取代苯甲酸(2)与2,6-吡啶二甲酰肼(3)在POCl3作用下,"一锅煮"法合成6个结构对称的含吡啶环的芳香醚-噁二唑4a～4f.通过MS,IR,1HNMR,元素分析等手段对其结构进行了表征.化合物的荧光性能测定结果显示此类化合物具有良好的荧光性,其荧光发射波长均在347～507nm范围内,最大荧光发射波长在384nm附近处,且荧光强度较强.在芳环上引入5-Br基团(4e,4f),化合物的荧光发射波长发生红移,荧光强度有所减弱.以硫酸奎宁作参比,测定6个目标产物的荧光量子产率,5-Br基团的引入对荧光量子产率没有明显影响.同时讨论了代表性产物4a在不同溶剂中最大荧光激发波长处的荧光量子产率,发现溶剂极性对该类化合物的荧光量子产率基本没有影响。

In order to explore new highly organic electroluminescent materials, six symmetrical aromatic oxide-oxadiazoles containing pyridine ring 4a-4f were synthesized through cyclization of substituted benzoic acid （2） with 2,6-dihydrazide pyridine （3） by ＂one-pot＂ method in POCl3. Their structures were con- firmed by MS, IR, ^1H NMR techniques and elemental analysis. The fluorescence spectra of the target com- pounds showed that the λem ranged from 347 to 507 nm, and the maximum λem were close to 384 nm, which showed that these compounds have good fluorescence with strong fluorescence intensity. When the 5-Br group was introduced into the aromatic ring （4c and 4f）, the fluorescent emission wavelength took place Einstein shift, and the fluorescent intensity decreased a little. Using quinine bisulphate as a reference, the fluorescence quantum yields were all tested, and the introduction of 5-Br group had no visible effect on fluorescence quantum yield. The fluorescence quantum yields of representative 4a in different solvents at maximum excitation wavelength were also measured and the results showed that the polarity of the solvents hardly had any relation to the fluorescence quantum yields of the target compounds.