3-(Ammonio-meth-yl)pyridinium dibromide.

Area of Science:

• Crystal Engineering
• Supramolecular Chemistry
• Organic Chemistry

Background:

• Understanding the self-assembly of organic salts is crucial for designing functional materials.
• Pyridinium salts are versatile building blocks in supramolecular chemistry.
• Hydrogen bonding and pi-pi interactions play key roles in crystal packing.

Purpose of the Study:

• To elucidate the crystal structure of the 3-methyl-pyridinium bromide salt.
• To analyze the intermolecular interactions governing the crystal packing.
• To characterize the supramolecular architecture formed by the salt.

Main Methods:

• Single-crystal X-ray diffraction was employed to determine the molecular and crystal structure.
• Analysis of hydrogen bonding networks (N(py)-H⋯Br, C-H⋯Br, H(2)N-H⋯Br).
• Investigation of pi-pi interactions between pyridinium rings.

Main Results:

• The 3-methyl-pyridinium cation exhibits a nearly planar 3-methyl-pyridinium unit.
• A robust supramolecular layered structure is formed via six distinct hydrogen bonds.
• Weak pi-pi interactions between adjacent cationic rings were observed with a centroid-centroid distance of 3.891 Å.

Conclusions:

• The crystal structure is dominated by a combination of hydrogen bonding and pi-pi interactions.
• The observed supramolecular layers are built from alternating R(2)(4)(10) and R(2)(4)(8) loops.
• This detailed structural analysis provides insights into the solid-state behavior of pyridinium salts.