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Updated: Jun 1, 2026
09:34
Synthesis of Information-bearing Peptoids and their Sequence-directed Dynamic Covalent Self-assembly
Published on: February 6, 2020
2,3-Diamino-pyridinium 4-hydroxy-benzoate
Hoong-Kun Fun1, Kasthuri Balasubramani
1X-ray Crystallography Unit, School of Physics, Universiti Sains Malaysia, 11800 Universiti Sains Malaysia, Penang, Malaysia.
Summary
This study characterizes a novel salt composed of a protonated pyridine derivative and a 4-hydroxy-benzoate anion. Crystal structure analysis reveals hydrogen bonding and pi-pi interactions forming a stable 3D network.
Area of Science:
- Crystallography
- Supramolecular Chemistry
- Organic Chemistry
Background:
- Protonation of nitrogen heterocycles is crucial in various chemical and biological systems.
- Benzoate derivatives are widely studied for their structural and functional properties.
- Understanding intermolecular interactions is key to designing novel materials.
Purpose of the Study:
- To elucidate the crystal structure of the title compound, a salt formed between a protonated pyridine derivative and 4-hydroxy-benzoate.
- To investigate the hydrogen bonding and π-π interactions governing the crystal packing.
- To characterize the supramolecular architecture of the resulting three-dimensional network.
Main Methods:
- Single-crystal X-ray diffraction was employed to determine the molecular and crystal structure.
- Analysis of hydrogen bonding (N-H⋯O, O-H⋯O, C-H⋯O) and π-π stacking interactions.
- Identification of characteristic ring motifs (e.g., R(2)(2)(8)).
Main Results:
- The pyridine nitrogen atom is protonated, forming a pyridinium cation.
- The 4-hydroxy-benzoate anion exhibits a slight twist of the carboxylate group out of the benzene ring plane (3.77°).
- A robust network is formed via N-H⋯O, O-H⋯O, and C-H⋯O hydrogen bonds, along with π-π interactions between pyridinium rings (centroid-centroid distance: 3.6277 Å).
Conclusions:
- The crystal structure is stabilized by a combination of strong hydrogen bonds and π-π stacking interactions.
- The observed supramolecular arrangement results in a stable three-dimensional network.
- This study provides insights into the self-assembly of organic salts and their structural characteristics.
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