Synthesis, Properties and Fundion of Cage-shaped Oligothiophenes

不幸的是，我们未能得到目标化合物，即寡聚噻吩链上的笼状分子，我们制备了一种目标化合物的前体-为了使三（2-噻吩基）硅烷衍生物的噻吩环官能化，硅原子上的第四取代基的选择是重要的。为了保护碳硅键不受反应物的影响，需要空间位阻取代基。我们发现异丁基对某些反应是不利的，但它仍然是寻找更好的取代基的必要条件。钯催化氧化偶联三乙炔衍生物制备了二乙炔桥连的笼状化合物，但产率较低。通过X射线晶体学确定了化合物的结构。在晶体中，它具有C3对称性，可能是由于长的碳-硅键。紫外-可见光谱和荧光光谱反映了硅原子的影响。虽然没有观察到显着的红移相比，非笼状类似物，吸收系数显着增加。笼状化合物显示出较强的荧光。

Unfortunately, we could not obtain the target compounds, which is cage molecules contsracted with oligothiophene chains, we prepared a cage compound bridged with diacetylene units, a precursor of the target, and got several new findings during the synthetic studuies.The most bothering feauture is a unexpected high reactivity of bond between silicon and carbon on thiophen ring. To functionalize thiophene rings of tris (2-thienyl) silane derivatives, the selection of the fourth substituent on the silicon atom is important. Sterically hindered substituent is requared for protection of carbon-silicon bond from reactants. We found that isobutyl group is bearable to some reactions, but it is still nessesary for searching better substituent.The cage compound bridged with diacetylene units is prepared by Pd-catalyzed oxidative coupling of triethynyl derivative, though the yield was low. The structure of the compound was determined by X-ray crystallography. In crystal, it has C3 symmetry, propably due to the long carbon-silicon bond. Furthermore, the UV-Vis and fluorescence spectra reflect the effect of silicon atom. While significant bathochromic shift was not observed by comparison with non-caged analoge, absorption coefficients were remarkably increased. Relatively strong fluorescent was shown on the cage compound.