Investigation On The Chiral Structure Controlled By The Metal Single Crystal Surface With 4-ethynyltriphenylamine Molecules

The precise construction of a unitary mirror isomer at the supramolecular level is currently one of the challenges in the field of chiral science.In this dissertation,the two-dimensional surface chiral structure of prochiral 4-ethynyltriphenylamine(ETPA)molecules induced by the surface of different metal single crystals is studied by ultra-high vacuum scanning tunneling microscopy(STM).The main achievements in this dissertation are presented as below:Three kinds of racemic self-assembly structures of ETPA molecules with different orientations are formed on Ag(111)and Cu(111)surfaces.Two kinds of chiral Z-shaped units are formed by recognition between the same chiral molecules on Cu(111)surface.The chiral chains formed by these Z-shaped units are combined alternately to form a racemic self-assembly structure;On the surface of Ag(111),two kinds of chiral molecules are alternately arranged to form a heterochiral chain,and the homochiral molecular recognition occurs between the chains to form a whole structure.The ETPA molecules on the surface of Cu(110)mainly form two unitary mirror isomers.The same chiral ETPA molecules form the characteristic structure of bright chains and dark chains spacing arrangement by ?-? stackings,C-H···?interactions and C-H·· Cu bonds.The chiral Kagomé structures composed of 4-azidobenzoic acid(ABA)molecules with chiral cavities on the surface of Cu(111)are used as the host templates to control the molecular structure of ETPA.STM observations show thar Kagomé-B structure with chiral cavities regulates the formation of chiral nanostructures,realizing the chiral recognition and separation of ETPA molecules.This discovery provides a feasible approach for the construction of chiral nanomaterials,chirality recognition and separation in ultra-high vacuum.