Anthracene-based Derivatives： Synthesis, Photophysical Properties and Electrochemical Properties

A series of anthracene-based derivatives, namely, 9-（4-phenyl）anthracene（1）, 9-（4-phenylethynyl）- anthracene（2） and 9, 10-bis（phenylethynyl）anthracene（3）, was synthesized by the Suzuki/Sonogashira cross-coupling reactions in good yields. These compounds were fully characterized by X-ray crystallography, thermogravimetric analysis（TGA）, differential scanning calorimetry（DSC）, UV-Vis absorption and fiuorescence（FL） spectroscopy, as well as density functional theory（DFT） calculations. Single-crystal X-ray analysis revealed that the packing structures were influenced by the terminal substitutions. All the compounds exhibited high thermal stability（Td=221---484 ~C） and blue emission with a high quantum yield（~bf =0.20--0.75）. As the number of substituents increased, the decomposition temperatures（Td） of these compounds increased in the following order： 1〈2〈3. Experiments on the photophysical properties revealed that different substituents strongly affected the optical properties. In particular, compound lb with the electron-withdrawing group（--CHO） exhibited a larger Stokes shift（113 nm） than the other compounds. Investigation of the electrochemical properties of these compounds showed that the HOMO-LUMO energy gaps（Egap） decreased obviously as the degree of conjugation increased.