对称4-枝和8-枝噁二唑衍生物的合成与荧光性质

采用Wittig-Horner和Heck反应合成了3个对称多枝1,3,4]-噁二唑衍生物2,5-双{4-{4-N,N-二(4-溴苯基)-氨基] 苯乙烯基}苯基}-1,3,4-噁二唑(BrPASPO), 2,5-双{4-{4-{N,N-二{4-{4-5-(4-叔丁基苯基)-1,3,4-噁二唑基-2-]苯乙烯基}苯基}氨基}苯乙烯基}苯基}-1,3,4-噁二唑(TPASPO)和2,5-双{4-{4-{N,N-二{4-{3,5-二5-(4-叔丁基苯基)-1,3,4-噁二唑基-2]-苯乙烯基}苯基}氨基}苯乙烯基}苯基}-1,3,4-噁二唑(OPASPO). 目标化合物的结构经过红外光谱、核磁共振氢谱、质谱和熔点确认. 在CH2Cl2溶液中三者的最大吸收波长分别在403 (BrPASPO), 408 (TPASPO)和409 nm (OPASPO), 荧光发射峰分别为495 (BrPASPO), 509 (TPASPO)和506 nm (OPASPO). 化合物TPASPO和OPASPO在CH2Cl2溶液中的荧光量子产率分别为0.47和0.45. 8枝化合物的荧光寿命高于4枝化合物. 对称多枝化合物具有很强的分子内电荷转移能力和荧光发射能力.

Synthesis and Fluorescence Properties of Symmetrical 4-Branched and 8-Branched 1,3,4-Oxadiazole Derivatives

Three novel symmetrical multi-branched 1,3,4-oxadiazole derivatives, 2,5-bis{4-{4-N,N-di- (4-bromophenyl)amino]styryl}phenyl}-1,3,4-oxadiazole (BrPASPO), 2,5-bis{4-{4-{N,N-di{4-{4-{5-4- (tert-butyl)phenyl]-1,3,4-oxadiazol-2-yl}styryl}phenyl}amino}styryl}phenyl}-1,3,4-oxadiazole (TPASPO) and 2,5-bis{4-{4-{N,N-bis{4-{3,5-di{5-4-(tert-butyl)phenyl]-1,3,4-oxadiazol-2-yl}styryl}phenyl}amino}- styryl}phenyl}-1,3,4-oxadiazole (OPASPO) were synthesized through Wittig-Horner and Heck reactions. Their structures were characterized by IR, 1H NMR, MS, and melting points. The maximum absorption peaks in dichloromethane were at 403 nm for BrPASPO, 408 nm for TPASPO and 409 nm for OPASPO, respectively. The maximum emission wavelengths were at 495 nm for BrPASPO, 509 nm for TPASPO, and 506 nm for OPASPO in dichloromethane, respectively. In CH2Cl2 the fluorescence quantum yields were 0.47 for TPASPO and 0.45 for OPASPO. In CH2Cl2 the fluorescence lifetime of 8-branched OPASPO was longer than that of 4-branched TPASPO. The strong intra-molecular charge transfer existed in these sym-metrical 4-branched and 8-branched compounds, which can enhance the ability of fluorescence emission.