Namba Genki, Mimura Yuki, Imai Yoshitane, Inoue Ryo, Morisaki Yasuhiro
Department of Applied Chemistry for Environment, School of Science and Technology, Kwansei Gakuin University, 2-1 Gakuen, sanda, Hyogo, 669-1337, Japan.
Department of Applied Chemistry, Faculty of Science and Engineering, Kindai University, 3-4-1 Kowakae, Higashi-Osaka, Osaka, 577-8502, Japan.
Chemistry. 2020 Nov 20;26(65):14871-14877. doi: 10.1002/chem.202003188. Epub 2020 Oct 6.
Optically active X-shaped molecules based on the planar chiral [2.2]paracyclophane building block were prepared, in which di(methoxy)terphenyl units were stacked on the central benzene rings. At 25 °C, anisolyl rings freely rotate in solution, while in the crystal form, they are fixed by intramolecular CH-π interactions, thereby leading to the expression of the axial chirality, i.e., propeller chirality was exhibited by the planar chiral [2.2]paracyclophane moiety. The X-shaped molecule exhibited good circularly polarized luminescence (CPL) profiles with moderate Φ and a large g value in the order of 10 at 25 °C, in solution. In contrast, at -120 °C, dual CPL emission with opposite signs was observed. According to the theoretical studies, the rotary motion of the anisolyl units is suppressed in the excited states, and so emission from two isomers could be observed. These results demonstrate that the axial chirality was controlled by the planar chirality, leading ultimately to propeller chirality.
制备了基于平面手性[2.2]对环芳烷结构单元的旋光X形分子，其中二（甲氧基）三联苯单元堆积在中心苯环上。在25℃时，茴香基环在溶液中自由旋转，而在晶体形式中，它们通过分子内CH-π相互作用固定，从而导致轴向手性的表达，即平面手性[2.2]对环芳烷部分表现出螺旋桨手性。该X形分子在25℃的溶液中表现出良好的圆偏振发光（CPL）谱，具有适度的Φ和大约10的大g值。相比之下，在-120℃时，观察到具有相反符号的双重CPL发射。根据理论研究，茴香基单元的旋转运动在激发态中受到抑制，因此可以观察到两种异构体的发射。这些结果表明，轴向手性由平面手性控制，最终导致螺旋桨手性。
Zotero 插件