Synthesis and Photophysical Properties of Chalcophenes-Embedded Cycloparaphenylenes

[n]­Cyclo-4,4′-biphenylene-2″,5″-thienylenes ([n]­CP2T, n = 3, 4), [n]­cyclo-4,4′-biphenyl-ene-2″,5″-selenylenes ([n]­CP2S, n = 3, 4), and [n]­cyclo-4,4′-biphenylene-2″,5″-ethylenedioxythienylenes ([n]­CP2E, n = 3) were synthesized in few steps with high overall yields. These nanorings were prepared through platinum-mediated cyclooligomerization of 2,5-bis­(4-pinacolboryl-phenyl)­chalcophenes. The X-ray crystallographic analysis of [4]­CP2S showed that it employed a cone-shaped conformation in the solid state. Furthermore, their photophysical properties were investigated by using the UV–vis absorption spectra and fluorescence spectra. In particular, selenophene and 3,4-ethylenedioxythiophene-embedded cycloparaphenylenes, which showed significant red shifts in the UV–vis absorption and fluorescence spectra compared with thiophene analogues, are reported here for the first time.

[n]­环-4,4′-联苯撑-2″,5″-噻吩撑类化合物（[n]­CP2T，n=3、4）、[n]­环-4,4′-联苯撑-2″,5″-硒吩撑类化合物（[n]­CP2S，n=3、4）以及[n]­环-4,4′-联苯撑-2″,5″-乙二氧基噻吩撑类化合物（[n]­CP2E，n=3）经数步反应即可合成，且总产率优异。这类纳米环通过铂介导的2,5-双(4-频哪醇硼酸酯苯基)硫族吩的环寡聚反应制备得到。对[4]­CP2S的X射线晶体衍射分析显示，其在固态下呈锥形构象。此外，通过紫外-可见吸收光谱与荧光光谱对其光物理性质展开了研究。本文首次报道了硒吩与3,4-乙二氧基噻吩嵌入的环对亚苯基类化合物，相较于噻吩类同系物，它们的紫外-可见吸收光谱与荧光光谱均呈现显著红移。