Crystal structure of morpholin-4-ium cinnamate

Area of Science:

• Crystallography
• Supramolecular Chemistry
• Organic Chemistry

Background:

• Morpholine and cinnamic acid are common organic compounds.
• Understanding the solid-state behavior of organic salts is crucial for materials science.
• Hydrogen bonding plays a key role in the self-assembly of molecular structures.

Purpose of the Study:

• To investigate the crystal structure of the anhydrous salt formed from morpholine and cinnamic acid.
• To elucidate the hydrogen bonding interactions and their influence on the supramolecular architecture.
• To characterize the torsion angles and molecular conformation within the crystal lattice.

Main Methods:

• Single-crystal X-ray diffraction was used to determine the crystal structure.
• Analysis of hydrogen bonding networks, including three-center interactions.
• Identification of supramolecular assembly through chain and layer formation.

Main Results:

• The trans-cinnamate anion exhibits a significant rotation of the acid side chain out of the benzene plane (torsion angle = 158.54°).
• A distinctive asymmetric three-center cation-anion hydrogen bond involving one aminium H atom and the carboxylate group was observed.
• A second inter-species hydrogen bond was identified, leading to the formation of a [100] chain structure.
• Chains are further connected by C-H⋯O interactions, forming a supramolecular layer parallel to the (01-1) plane.

Conclusions:

• The study reveals the detailed crystal structure and hydrogen bonding patterns of morpholine cinnamate.
• The observed hydrogen bonding interactions dictate the formation of one-dimensional chains and two-dimensional supramolecular layers.
• This work contributes to the understanding of structure-property relationships in organic salts.