A Hydrogen-Bonded Organic Framework Based on Pyrazinopyrazine

Hydrogen-bonded organic frameworks (HOFs) composed of high-nitrogen-content p-conjugated molecules are expected to show multifunctionality. In this study, we studied on a HOF based on pyrazinopyrazine (PP), which is one of the simplest and the most essential structural motifs of high-nitrogen-content polycyclic aromatic hydrocarbons. We describe synthesis of a PP-based building block molecule with four carboxyphenyl groups (CP-PP), spectroscopic and electronic properties of CP-PP and its ester precursor, structures of CP-PP-based HOFs, and thermal behaviors of the HOFs. Interestingly, the initial framework with hydrogen-bonded rhombic two-dimesnional (2D) network rapidly undergoes a guest release-induced three-step structural transformation into other frameworks, including a semiopening framework with small void, through rearrangement of hydrogen bonds. These results provide insight into design new functional N pi-HOFs and contribute to solid-state chemistry on porous molecular crystalline materials.

Automated summary

This study focused on a hydrogen-bonded organic framework (HOF) based on pyrazinopyrazine (PP), investigating its synthesis, spectroscopic and electronic properties, structures, and thermal behaviors. The research found that the framework rapidly undergoes structural transformation through rearrangement of hydrogen bonds, providing insights for designing new functional N pi-HOFs.