5-ammoniosalicylic acid chloride monohydrate

Area of Science:

• Crystallography
• Chemical Physics
• Materials Science

Background:

• Understanding the crystal structure of amino acid derivatives is crucial for predicting their physical and chemical properties.
• Ionic compounds involving amino acids and inorganic ions exhibit diverse hydrogen bonding networks.
• The role of water molecules and counter-ions in crystal lattice formation requires detailed investigation.

Purpose of the Study:

• To elucidate the crystal structure of the title compound (C7H8NO3+.Cl-.H2O).
• To analyze the hydrogen bonding network and its influence on the crystal architecture.
• To investigate the arrangement of cations, anions, and water molecules in the solid state.

Main Methods:

• Single-crystal X-ray diffraction was employed to determine the crystal structure.
• Analysis of hydrogen bond donor-acceptor distances and angles.
• Topological analysis of the hydrogen bond network using second-level graphs.

Main Results:

• The compound crystallized in the centrosymmetric space group P2(1)/c as an ionic salt with proton transfer to the amino group.
• All hydrogen atoms involved in hydrogen bonding (from N, carboxyl, hydroxyl, and water) were found to be ordered.
• Hydrogen bonds formed an intricate three-dimensional network, linking acid cations indirectly via chloride ions and water molecules.
• Finite patterns were observed to be more prevalent than chains and rings in the network topology.

Conclusions:

• The crystal structure is characterized by an ordered, ionic arrangement stabilized by extensive hydrogen bonding.
• The indirect linkage of cations through water and chloride ions results in a robust 3D supramolecular architecture.
• The observed network topology, dominated by finite patterns, provides insights into the self-assembly principles of such ionic compounds.