文献类型：期刊文献

英文题名：Steering Selective Formation and 2D Crystallization of [4]Radialenes on Au(111) via [1+1+1+1] Cycloaddition of Isocyanides and Enantioselective Molecular Recognition

作者：Liu, Jian-Wei[1,2,3]; Wang, Ying[1,2,3]; Wu, Cui-Ping[1,2,3]; Li, Jia-Xin[1,2,3]; Kang, Li-Xia[1,2,3]; Fu, Jian-Hui[1,2,3]; Gong, Wen-Wen[1,2,3]; Liu, Pei-Nian[1,2,3]; Li, Deng-Yuan[1,2,3]

机构：[1] State Key Laboratory of Natural Medicines, School of Pharmacy, China Pharmaceutical University, Nanjing, 211198, China; [2] School of Chemistry and Molecular Engineering, East China University of Science & Technology, Shanghai, 200237, China; [3] ChangXin Memory Technologies, Inc., [CXMT]No. 799, Qide Road, Economic and Technological Development Area, Hefei, 230601, China

年份：2026

外文期刊名：arXiv

收录：EI(收录号：20260307965)

语种：英文

外文关键词：Atomic force microscopy - Coordination reactions - Cycloaddition - Density functional theory - Enantioselectivity - Functional materials - Geometry - Gold compounds - Molecular crystals - Scanning tunneling microscopy

摘要：Conjugated carbon rings are fundamental skeletons of organic functional materials, and their selective formation is of paramount importance in molecular materials engineering. However, steering the formation and 2D crystallization of conjugated carbon rings on the surface with high chemo- and stereoselectivities remains a great challenge. Here, we report a highly chemoselective [1+1+1+1] cycloaddition of isocyanides on the Au(111) surface, which affords the stereospecific tetraaza[4]radialene products and further enables their long-range-ordered 2D crystallization via enantioselective molecular recognition. Using the progressive annealing method, we found that at room temperature, isocyanides undergo a coordination reaction with Au adatoms to form two-fold symmetric isocyanide-Au-isocyanide complexes. In contrast, gradually increasing the annealing temperature induces the transformation of these complexes and subsequent covalent polymerization, leading to the selective generation of tetraaza[4]radialenes with homotactic configurations. The tetraaza[4]radialenes further assemble into 2D homochiral molecular crystals through enantioselective molecular recognition driven by multiple C–H···Cl hydrogen-bonding interactions. By combining scanning tunneling microscopy/spectroscopy and non-contact atomic force microscopy, we determined the atomic structure and molecular orbitals of tetraaza[4]radialene, confirming that its four-membered ring adopts a planar geometry with a localized lowest unoccupied molecular orbital. Density functional theory calculations suggest that the [1+1+1+1] cycloaddition process involves stepwise formation of C–C bonds and its high selectivity arises from the spatial steric hindrance. Our findings provide new insights into the selective formation of conjugated rings on surfaces and have implications for engineering 2D homochiral molecular crystallization. ? 2026, CC BY.