Coronene guest molecule selectivity in host templates formed by hydrogen bonding and van der Waals forces at liquid/solid interfaces

Hydrogen bonding and van der Waals forces are important non-covalent interactions for constructing supramolecular self-assembly networks. The directivity of hydrogen bonding brings about rich and diverse structures and properties for hydrogen-bonded organic frameworks (HOFs), and has been an ongoing interest for researchers. However, there are few studies on the selective adsorption of the same guest molecule in a host template constructed by different intermolecular interactions. In this work, the self-assembly behaviors of two carboxylic acid molecules, namely 1,3,5-tris(4-(3,5-dicarboxyphenyl)diphenyl)benzene (H6PDB) and 1,3,5-tris(4-(3,5-dicarboxyphenylacetylene)phenyl)benzene (H(6)PAB), were studied by scanning tunneling microscopy (STM). The molecules self-assembled into structures with two kinds of cavities, where the hexagonal cavities demonstrated different behaviors when accommodating guest coronene (COR) molecules. In H(6)PAB and hexaphenylbenzene derivative (HPB) templates, the COR guest molecules preferentially adsorbed in the H(6)PAB host templates, showing selective adsorption.