Intermediate States Directed Chiral Transfer on a Silver Surface
Biao Yang†, Nan Cao†, Huanxin Ju‡, Haiping Lin*†, Youyong Li†, Honghe Ding‡, Jinqiang Ding†, Junjie Zhang†, Chencheng Peng†, Haiming Zhang†, Junfa Zhu‡, Qing Li*†, and Lifeng Chi*†
†Institute of Functional Nano and Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, 199 Ren’ai Road, Suzhou 215123, P. R. China
‡National Synchrotron Radiation Laboratory and Collaborative Innovation Center of Suzhou Nano Science and Technology, University of Science and Technology of China, Hefei, Anhui 230029, China
Chiral synthesis on surfaces has acquired tremendous interest. We herein report a novel approach of two-dimensional chiral transfer directed by metal–organic intermediate states on a silver surface. With initial deposition at low temperature, the achiral 4,4′-dihydroxybiphenyl molecules self-assemble into large scale two-dimensional networks with 4-fold symmetry via intermolecular hydrogen bonding. Fine controlled annealing, however, leads to the formation of tetramer-like chiral metal–organic hybrids, which self-organize into enantiomeric islands on the Ag(100) surface. Subsequent ortho C–C couplings of the reactants lead to dimer products. Of great importance, the chirality expressions of the dimer products are observed to be transferred directly from that of the tetramer intermediate states. The detailed reaction pathways are rationalized by DFT calculations and synchrotron-based XPS experiments, demonstrating the mechanisms of the chiral transfer.