Pyromellitic acid-sarcosine (1/2).

Area of Science:

• Crystallography
• Supramolecular Chemistry
• Organic Chemistry

Background:

• Adduct formation is crucial for designing novel materials.
• Understanding molecular interactions aids in predicting material properties.
• Pyromellitic acid and sarcosine are key components in various chemical syntheses.

Purpose of the Study:

• To elucidate the crystal structure of the pyromellitic acid-sarcosine adduct.
• To investigate the hydrogen bonding interactions within the adduct.
• To characterize the molecular conformation and protonation states.

Main Methods:

• Single-crystal X-ray diffraction was employed to determine the crystal structure.
• Analysis of bond lengths, angles, and torsion angles.
• Identification of hydrogen bond donors and acceptors.

Main Results:

• The compound crystallizes as an adduct of pyromellitic acid and sarcosine in their neutral forms.
• Sarcosine exists in a zwitterionic form with a protonated amine and deprotonated carboxyl group.
• Pyromellitic acid molecules retain all four carboxyl hydrogen atoms, with carboxyl groups rotated out of the ring plane.
• A three-dimensional hydrogen-bond network connects the acid and amino acid molecules.

Conclusions:

• The crystal structure reveals a stable adduct formed through extensive hydrogen bonding.
• The zwitterionic nature of sarcosine and the conformation of pyromellitic acid are key to the network formation.
• This structural insight is valuable for designing related supramolecular architectures.