Cinchoninium L-tartrate tetrahydrate

Area of Science:

• Crystallography
• Organic Chemistry
• Materials Science

Background:

• Cinchonine is a cinchona alkaloid with a complex molecular structure.
• Understanding the solid-state properties of its salts is crucial for various applications.
• Hydrated salts can exhibit unique structural and chemical characteristics.

Purpose of the Study:

• To elucidate the crystal structure of (3R,4S,8R,9S)-cinchoninium (2R,3R)-tartrate tetrahydrate.
• To analyze the protonation state and intermolecular interactions within the salt.
• To compare the observed conformation with theoretical calculations.

Main Methods:

• Single-crystal X-ray diffraction was employed to determine the molecular and crystal structure.
• Analysis of bond lengths, angles, and intermolecular contacts was performed.
• Comparison with gas-phase energy calculations was conducted.

Main Results:

• The structure confirmed the hydrated salt of cinchonine, C19H23N2O+*C4H5O6-*4H2O.
• The cinchoninium cation showed a typical protonated quinuclidinic N atom, and the tartrate moiety was mono-ionized.
• The relative orientation of quinoline and quinuclidine systems matched common cinchona salt structures and energy minima.
• An extensive network of intermolecular hydrogen bonds was observed parallel to the bc plane.

Conclusions:

• The crystal structure provides detailed insights into the solid-state arrangement of cinchoninium tartrate tetrahydrate.
• The observed hydrogen bonding network influences the separation of apolar layers within the crystal.
• This structural information contributes to the understanding of cinchona alkaloid salt behavior and potential applications.