作者:Delphine Felder-Flesch、Leszek Rupnicki、Cyril Bourgogne、Bertrand Donnio、Daniel Guillon
DOI:10.1039/b509081d
日期:——
Two novel cholesterol-based [60]fullerene hexaadducts 1 and 2 bearing respectively 12 and 10 mesogenic cholesterol moieties were prepared following Hirsch's methodology. Both hexaadducts 1 and 2 showed a smectic A phase from slightly above room temperature up to 165 °C for 1 and 180 °C for 2, whereas the malonate mesogenic promoter 5 displayed two monotropic unidentified phases at 41 °C and 67 °C and a chiral nematic phase between 67 °C and 88 °C. An increase of the mesophase stability of about 100 °C as well as a near room temperature mesomorphism was thus obtained through C60-grafting. The design consisting of the polyaddition of cholesterol moieties on the carbon truncated icosahedron used as a spherical template to create new 3D architectures, appears then to be a method of choice to obtain stable anisotropic materials and to prevent the C60 aggregation tendency. As deduced by X-ray diffraction studies, and supported by molecular modelling calculations, the two supermolecules 1 and 2 self-organize into bi-layer structures which consist of a median C60-rich slab, sandwiched between cholesteryl-containing outer layers.
按照赫希的方法制备了两种新型胆固醇基[60]富勒烯六加合物 1 和 2,它们分别含有 12 个和 10 个中生胆固醇分子。六加合物 1 和 2 在略高于室温至 165 °C(1)和 180 °C(2)的温度范围内都显示出熔融 A 相,而丙二酸酯介生促进剂 5 在 41 °C和 67 °C的温度范围内显示出两个单向性不明相,在 67 °C至 88 °C的温度范围内显示出一个手性向列相。通过 C60 接枝,介相稳定性提高了约 100 °C,并获得了接近室温的介形态。在作为球形模板的碳截顶二十面体上多元添加胆固醇分子以创建新的三维结构的设计,似乎是获得稳定的各向异性材料和防止 C60 聚集趋势的首选方法。根据 X 射线衍射研究的推断和分子建模计算的支持,两个超级分子 1 和 2 自组织成双层结构,由中间富含 C60 的板层和夹在含胆固醇外层之间的板层组成。