以3,5-二羟基苯甲醇和4-羟基-4’-硝基偶氮苯为原料合成一种新的含氨基的偶氮中间体,然后与1,6,7,12-四(4-叔丁基苯氧基)-3,4,9,10-苝四甲酸二酐缩合得到新型偶氮-苝酰亚胺二元染料(AZO-PTCDI)。采用紫外可见-吸收光谱和荧光光谱研究UV光照时间和浓度等因素对AZO-PTCDI光响应行为的影响。研究结果表明:AZO-PTCDI的浓度越大,偶氮基团在353 nm处的特征吸收峰强度随UV光照时间的延长而下降越缓慢,表明偶氮生色团由反式结构向顺式结构的转变速度越慢;对于相转移法组装形成的AZO-PTCDI聚集体结构,两相溶剂甲醇与三氯甲烷的体积比越大,越容易组装形成较规整的类纤维状结构;将未光照和UV光照后的AZO-PTCDI三氯甲烷溶液快速扩散到甲醇中所得到的聚集体形貌结构存在明显差异,前者表现为短的一维结构,后者为不规则的类球状结构,表明光照驱动偶氮基团的反式结构向顺式结构的转变导致苝酰亚胺的N-取代基的几何空间构型发生改变,削弱了分子间的π-π作用和烷基链的疏水作用力,致使聚集体分子排列无序化。
A new azo compound containing amino group was synthesized starting from 3, 5-dihydroxybenzyl alcohol and 4-hydroxy-4'-nitro-azobenzene. Then a novel azo-perylene bisimide dyad(AZO-PTCDI) was received through condensation of the azo compound and 1, 6, 7, 12-tetra(4-tertbutyl phenoxy)-3, 4, 9, 10-perylene tetracarboxylic dianhydride. The influences of UV irradiation time and dyad concentration on the optical properties of AZO-PTCDI were investigated by UV-Vis absorption spectra and fluorescence spectra. The results show that higher concentration of the dyad slows down with the decrease of absorption intensity of AZO group, indicating that the rate of cis-trans transition is slower with the increase of the concentration. For the structure of AZO-PTCDI aggregates prepared by the phase transfer assembly, the larger the volume ratio of methanol and chloroform, the more regular the fibrous aggregates assembled. Finally. There is apparent difference between the SEM images of aggregates assembled from the photoisomerized AZO-PTCDI in chloroform and that obtained without photoisomerization of AZO-PTCDI, which suggests that the former is irregular spheres and the latter is short fibrous structure. Due to the photo-induced cis-trans transition, the geometrical configuration changes of N-substituent in PTCDI weaken the π-π interactions of perylene cores and hydrophobic interactions of alkyl chains, leading to the disordered arrangement of molecules.