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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-Amino-pyridinium 4-hydroxy-benzoate.
Ching Kheng Quah1, Samuel Robinson Jebas, Hoong-Kun Fun
1X-ray Crystallography Unit, School of Physics, Universiti Sains Malaysia, 11800 USM, Penang, Malaysia.
Summary
This study details the crystal structure of a compound, revealing specific molecular orientations and bonding. Hydrogen bonds and pi-pi interactions form an intricate three-dimensional network, crucial for understanding crystal packing.
Area of Science:
- Crystallography
- Supramolecular Chemistry
- Materials Science
Background:
- Understanding the intermolecular forces governing crystal structures is essential for predicting material properties.
- The 4-hydroxybenzoate anion and its derivatives are common motifs in medicinal chemistry and materials science.
- Investigating hydrogen bonding and pi-pi interactions provides insights into crystal engineering and molecular assembly.
Purpose of the Study:
- To elucidate the crystal structure of the title compound, C(5)H(7)N(2)(+)·C(7)H(5)O(3)(-).
- To analyze the specific geometric arrangements and intermolecular interactions, including hydrogen bonds and pi-pi stacking.
- To characterize the three-dimensional network formed by these interactions.
Main Methods:
- Single-crystal X-ray diffraction was employed to determine the molecular and crystal structure.
- Analysis of bond lengths, bond angles, and intermolecular distances.
- Identification and quantification of hydrogen bonds (O-H⋯O, N-H⋯O, C-H⋯O) and pi-pi interactions.
Main Results:
- The crystal structure revealed a specific twist (8.78(5)°) between the carboxylate group and the benzene ring of the 4-hydroxybenzoate anion.
- A robust three-dimensional network was formed through various hydrogen bonds.
- Significant pi-pi interactions were observed between the benzene and pyridinium rings, with centroid-centroid distances of 3.5500(6) Å and 3.6594(6) Å.
Conclusions:
- The title compound exhibits a well-defined crystal structure governed by a combination of hydrogen bonding and pi-pi interactions.
- These interactions lead to the formation of an extensive three-dimensional supramolecular network.
- The findings contribute to the understanding of crystal packing in organic salts and inform future crystal engineering efforts.
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