Tetra-methyl-ammonium hemi(terephthalate) dihydrate

Area of Science:

• Crystal chemistry
• Supramolecular chemistry

Background:

• Terephthalate anions and tetramethylammonium cations are common building blocks in crystal engineering.
• Hydrogen bonding plays a crucial role in the self-assembly of crystalline materials.

Purpose of the Study:

• To elucidate the crystal structure of tetramethylammonium terephthalate dihydrate.
• To investigate the role of hydrogen bonding and guest-host interactions in the formation of the crystal lattice.

Main Methods:

• Single-crystal X-ray diffraction analysis was employed to determine the molecular and crystal structure.
• Analysis of hydrogen bonding networks and intermolecular interactions.

Main Results:

• The crystal structure consists of undulating hydrogen-bonded host layers formed by terephthalate dianions and water molecules.
• Tetramethylammonium cations are arranged as guest species between these host layers, creating a sandwich-like architecture.
• The terephthalate dianion exhibits twofold symmetry with a dihedral angle of 23.5(2)° between the carboxylate group and the aromatic ring.

Conclusions:

• The study reveals a novel crystal structure stabilized by extensive hydrogen bonding and host-guest interactions.
• The observed sandwich-like arrangement highlights the potential for designing ordered supramolecular architectures using organic cations and anions.