Rodríguez Luis M, Gómez Paula, Más-Montoya Miriam, Abad José, Tárraga Alberto, Cerdá Jorge I, Méndez Javier, Curiel David
Department of Surfaces and Coatings, Institute of Material Science of Madrid (ICMM-CSIC), Sor Juana Inés de la Cruz 3, 28049-, Madrid, Spain.
Department of Organic Chemistry, University of Murcia, Campus of Espinardo, 30100-, Murcia, Spain.
Angew Chem Int Ed Engl. 2021 Jan 25;60(4):1782-1788. doi: 10.1002/anie.202012100. Epub 2020 Dec 14.
The synthesis of a novel expanded π-conjugated system, namely benzotri(7-azaindole), BTAI, is reported. Its C symmetry along with the integration of six complementary donor and acceptor N-H⋅⋅⋅N hydrogen bonds in the conjugated structure promote the 2D self-assembly on Au(111) over extended areas. Besides, a perfect commensurability with the gold lattice endows the physisorbed molecular film with a remarkable stability. The structural features of BTAI result in two levels of surface chirality: Firstly, the molecules become chiral upon adsorption on the surface. Then, due to the favorable N-H⋅⋅⋅N hydrogen bond-directed self-assembly, along with the relative molecular rotation with respect to the substrate, supramolecular chirality manifests in two mirror enantiomorphous domains. Thus, the system undergoes spontaneous chiral resolution. LEED and STM assisted by theoretical simulations have been employed to characterize in detail these novel 2D conglomerates with relevant chiral properties for systems with C symmetry.
报道了一种新型扩展π共轭体系——苯并三（7-氮杂吲哚）（BTAI）的合成。其C对称性以及共轭结构中六个互补供体和受体N-H⋅⋅⋅N氢键的整合促进了在Au(111)上大面积的二维自组装。此外，与金晶格的完美适配赋予了物理吸附分子膜显著的稳定性。BTAI的结构特征导致了两个层面的表面手性：首先，分子在吸附到表面时变为手性。然后，由于有利的N-H⋅⋅⋅N氢键导向的自组装，以及相对于基底的分子相对旋转，超分子手性在两个镜像对映体域中表现出来。因此，该体系经历了自发的手性拆分。借助理论模拟的低能电子衍射（LEED）和扫描隧道显微镜（STM）已被用于详细表征这些具有相关手性性质的新型二维聚集体，这些聚集体具有C对称性。
