Nakabayashi Mahiro, Matsuo Takumi, Hayashi Shotaro
School of Engineering Science, Kochi University of Technology, 185 Tosayamada Miyanokuchi, Kami, Kochi, 782-8502, Japan.
Research Center for Molecular Design, Kochi University of Technology, 185 Tosayamada Miyanokuchi, Kami, Kochi, 782-8502, Japan.
Chemistry. 2023 Nov 2;29(61):e202302351. doi: 10.1002/chem.202302351. Epub 2023 Sep 21.
To realize organic integrated optoelectronic circuits, there is a need for anisotropic optical waveguides at the micro/nanoscale. Anisotropic alignment of one-dimensional-ordered supramolecular structures composed of light-emissive π-conjugated molecules in a crystal may meet the requirements of such waveguides. Here, a bipyridyl-appended acrylonitrile-based π-conjugated molecule was designed, which produced a one-dimensional supramolecular polymer constructed through non-covalent bonding between a lone pair in bipyridyl and a σ-hole in 1,4-diiodo-2,3,5,6-tetrafluorobenzene. The one-dimensional copolymer of bipyridyl and 1,4-diiodo-2,3,5,6-tetrafluorobenzene is aligned horizontally with the two-dimensional crystal surface because of the angle-controlled supramolecular synthons. As a result of control over the non-covalent bonding direction, anisotropic photoluminescence and photon transport (optical waveguiding) characteristics are realized by orienting the transition dipole moment horizontally with respect to the two-dimensional surface. Compared with the loss coefficient α =52 dB cm for the long-axis direction of the two-dimensional platelet cocrystal, a very large difference of α =2111 dB cm is present in the crystal short-axis direction. The anisotropic waveguiding ability, α /α , is estimated to be 41, which is more than an order of magnitude greater than previously reported two-dimensional platelet crystal waveguides. This supramolecular synthon provides an approach to designing anisotropic photon transporters and highly regulated optical logic circuits.
为了实现有机集成光电子电路，需要微纳尺度的各向异性光波导。由发光π共轭分子组成的一维有序超分子结构在晶体中的各向异性排列可能满足此类光波导的要求。在此，设计了一种联吡啶基取代的丙烯腈基π共轭分子，它通过联吡啶中的孤对电子与1,4 - 二碘 - 2,3,5,6 - 四氟苯中的σ空穴之间的非共价键合形成了一维超分子聚合物。由于角度控制的超分子合成子，联吡啶与1,4 - 二碘 - 2,3,5,6 - 四氟苯的一维共聚物与二维晶体表面水平排列。通过控制非共价键合方向，相对于二维表面水平取向跃迁偶极矩，实现了各向异性光致发光和光子传输（光波导）特性。与二维片状共晶体长轴方向的损耗系数α = 52 dB/cm相比，晶体短轴方向存在α = 2111 dB/cm的极大差异。各向异性波导能力α /α估计为41，比之前报道的二维片状晶体光波导大一个数量级以上。这种超分子合成子为设计各向异性光子传输体和高度可控的光学逻辑电路提供了一种方法。
