The cocrystal nicotinamide-succinic acid (2/1)

Area of Science:

• Crystal Engineering
• Supramolecular Chemistry
• Materials Science

Background:

• Nicotinamide and dicarboxylic acids are known to form cocrystals with diverse supramolecular architectures.
• The 2:1 nicotinamide-dicarboxylic acid cocrystal system commonly exhibits corrugated hydrogen-bonded sheets.
• Understanding cocrystal formation is crucial for designing materials with tailored properties.

Purpose of the Study:

• To elucidate the crystal structure of the 2:1 nicotinamide-succinic acid cocrystal.
• To identify the hydrogen bonding patterns and supramolecular synthons present.
• To investigate novel packing features and their implications for cocrystal design.

Main Methods:

• Single-crystal X-ray diffraction analysis was employed to determine the crystal structure.
• Analysis of hydrogen bonding interactions and supramolecular motifs (synthons).

Main Results:

• The asymmetric unit contains two independent nicotinamide molecules (anti and syn conformations) and two half succinic acid molecules.
• The structure exhibits acid-pyridine and amide-amide synthons, forming ladder-like arrangements of R(2)(2)(8) and R(4)(2)(8) rings.
• These units assemble into corrugated hydrogen-bonded sheets, a common feature, but with a novel dual-sheet arrangement due to distinct nicotinamide conformations.

Conclusions:

• The 2:1 nicotinamide-succinic acid cocrystal presents a unique supramolecular architecture with two distinct hydrogen-bonded sheets.
• The presence of both anti and syn nicotinamide conformations in the same structure is a novel packing feature.
• This finding contributes to the understanding of cocrystal polymorphism and offers insights for designing new functional materials.