Zwitterionic 1-{(1E)-[(4-hy-droxy-phen-yl)iminio]meth-yl}naphthalen-2-olate: crystal structure and Hirshfeld surface...

Area of Science:

• Crystallography
• Supramolecular Chemistry
• Organic Chemistry

Background:

• Zwitterions are neutral molecules with distinct positive and negative charges.
• Intramolecular hydrogen bonds play a crucial role in molecular conformation and stability.
• Understanding crystal packing is essential for predicting material properties.

Purpose of the Study:

• To characterize the crystal structure and intermolecular interactions of a novel zwitterion.
• To investigate the role of hydrogen bonding and pi-pi interactions in supramolecular assembly.
• To analyze the contribution of different contact types to the crystal lattice using Hirshfeld surface analysis.

Main Methods:

• Single-crystal X-ray diffraction was used to determine the molecular and crystal structure.
• Analysis of hydrogen bonding (N-H...O, O-H...O, C-H...O) and pi-pi stacking interactions.
• Hirshfeld surface analysis was employed to quantify the intermolecular interactions.

Main Results:

• The zwitterion, C17H13NO2, exhibits an intramolecular charge-assisted N+-H...O- hydrogen bond.
• A significant twist in the molecule is observed, with a C-N-C-C torsion angle of 39.42(8)°.
• Crystal packing features zigzag supramolecular chains along the a-axis, layered structures in the ab-plane, and stacking along the c-axis.
• Charge-assisted hydrogen bonding and pi-pi contacts (3.4905(12) Å) are key to layer formation.
• Hirshfeld surface analysis highlights the importance of C...H contacts between layers.

Conclusions:

• The studied zwitterion forms a stable crystal structure driven by strong intra- and intermolecular interactions.
• The molecular twist influences crystal packing and the formation of extended supramolecular architectures.
• Hirshfeld surface analysis provides quantitative insights into the dominant intermolecular forces governing crystal assembly.