1,4-bis[2-(4-pyridyl)ethenyl]-benzene衍生物热致变色研究

本文制备了三种在1,4-bis[2-(4-pyridyl)ethenyl]-benzene(bp-eb)上接枝不同烷基链长度的热致变色材料DC8、DC12、DC16. 在365 nm激发光下，随着温度升高，它们呈现出荧光颜色的改变，这种改变来自于晶体态与无定形态之间的转变. 此外，DC16也呈现出光致变色的性质. 通过差示扫描量热法测试得到的相转变温度高于实验过程中荧光颜色改变时的温度. 因此，这种变色行为来自于光与热共同作用的结果. 乙醇可以使粉末变回起始的晶体状态，从而使荧光颜色恢复，实现热致变色行为的可逆. 本研究对理解热致变色分子的结构-性质关系，指导热致变色分子设计具有重要意义.

Thermochromism of 1,4-Bis[2-(4-pyridyl)ethenyl]-benzene Derivatives

Three kinds of thermochromic materials (DC8, DC12, DC16) were synthesized by link-ing the rigid 1,4-bis[2-(4-pyridyl)ethenyl]-benzene (bpeb) with different lengths of alkyl chains. They exhibit remarkable fluorescent color changes under the irradiation of 365 nm light with elevating temperature, which is supposed to be caused by the transition between the crystal state and the amorphous state. Interestingly, the DC16 solid also has a photochromic character. It should be noticed that the phase transition temperatures of three materials measured by differential scanning calorimetry are higher than those of the fluorescence color changes during the heating process. Thus, the allochroic effect is attributed to the synergistic effect of both heating and photo-inducement (365 nm). Ethanol can turn the heated powder into the initial crystal again which indicates that their thermochromic behavior is reversible and makes the fluorescence recover.