Showing papers by "Wenli Deng published in 2021"

Solvent Effect on Halogen-Bonded Self-Assembled Nanostructures of a 2,9-Dibromo-Phenanthridine Derivative at the Liquid–Solid Interface

Abstract: Probing the halogen-bonded nanostructures of two-dimensional (2D) supramolecular self-assembly is essential to understand and engineer the nature of halogen bonding. However, exploring the formatio...

Scanning Tunneling Microscopy and Computational Simulation Studies of a Fluorenone-Based Organic Optoelectronic Material

Abstract: Scanning tunneling microscopy (STM) and computational simulation are utilized to systematically study an organic molecule, namely, a fluorenone derivative of 2-tridecyloxy-7-tetradecyloxy-9-fluoren...

Solvent Co-adsorption Changing the Type of Halogen-Based Bonds Associated with the Position of Bromine Substituents Revealed by Scanning Tunneling Microscopy

Abstract: A systematic investigation of the solvent co-adsorption effect on the self-assembly of 3,8-dibromo-6-(hexadecyloxy)phenanthridine (3,8-BHP) was performed at the liquid/graphite interface by scannin...

Halogen bonding controlled 2D self-assembled polymorphism of regioisomeric thienophenanthrene derivatives by coadsorption

Abstract: A thorough understanding of the halogen-bond-formation mechanism in surface-supported supramolecular assemblies is under explored compared with existing knowledge of hydrogen bonding. Here we report the self-assembly of regioisomeric bromine substituted thienophenanthrene derivatives (6,9-DBTD-C14 and 5,10-DBTD-C14) at the 1-bromo-hydrocarbon/highly oriented pyrolytic graphite (HOPG) interface. The chemical structures of these two kinds of molecules differ in the position of the bromine groups attached on the conjugated core. 6,9-DBTD-C14 molecules assemble into a dumbbell-like linear adlayer in different 1-bromo-hydrocarbon solvents, such as bromotetradecane (C14-Br), bromopentadecane (C15-Br), and bromohexadecane (C16-Br) at different solution concentrations resulting from coadsorption by van der Waals interactions and possible halogen and hydrogen bonding. By contrast, the self-assembly of 5,10-DBTD-C14 displays both solvent and concentration dependence. At the C14-Br/HOPG interface, only a mixed loose- and dense-packed backbone-like linear structure is obtained at different concentrations. At the C15-Br/HOPG interface, a dense-packed backbone-like linear structure at high concentrations and a matrix-like pattern at low concentrations are observed. At the C16-Br/HOPG interface, a loose-packed backbone-like linear structure at high concentrations and a bowknot-like linear adlayer at low concentrations are formed. The structural polymorphism derives from molecule–solvent van der Waals interactions between the alkyl chains and the halogen bonding between Br, S and –COO groups.