Role of Synergistic C-H•••N and C-H•••O H-Bonding Interactions in Self-Assemblies of a Phthalocyanine Derivative and Several Pyridine Derivatives

Phthalocyanine (Pc)-based fused derivatives are widely used materials in many nanotechnology fields, such as photovoltaic devices, pigments, and sensors, because of their excellent physical and chemical properties. It has been proven that most Pc molecules can self-assemble with ligands by the metal ligand coordination interaction or pi-pi stacking interaction, yet little is known about the supramolecular packing of H-bonded Pc derivatives. Herein, we report the self-assembly of rylene-annulated Pc (ZnPcPDI4) with a series of pyridine derivatives at the solid/liquid interface via synergistic C-H center dot center dot center dot N and C-H center dot center dot center dot O H-bonding interactions. We use scanning tunneling microscopy combined with theoretical simulations to demonstrate the interactions in the self assembled process. The intermolecular binding modes of Pcs with ligands and their thermodynamics stability are revealed by the combination of density functional theory and molecular dynamics simulations with the modified force field parameters. This study provides an innovative new method to build the 2D self-assembled nanostructures of Pcs by hydrogen bonds at the solid/liquid interface.