1-(2,3-Di-hydroxy-prop-yl)-4-{2-[4-(di-methyl-amino)-phen-yl]vin-yl}pyridinium chloride

Area of Science:

• Crystallography
• Solid-state chemistry
• Molecular structure analysis

Background:

• Understanding crystal structures is crucial for predicting material properties.
• Disorder in molecular crystals can significantly influence lattice symmetry and packing.
• Hydrogen bonding and other intermolecular forces dictate crystal architecture.

Purpose of the Study:

• To elucidate the crystal structure of the title compound, C18H23N2O2(+)·Cl(-).
• To investigate the impact of cation disorder on the overall crystal symmetry.
• To characterize the intermolecular interactions governing crystal packing.

Main Methods:

• Single-crystal X-ray diffraction was employed to determine the crystal structure.
• Analysis of crystallographic data identified two independent cations and anions per unit cell.
• Disorder in the cation's vinyl groups was quantified using occupancy parameters.

Main Results:

• The title compound, C18H23N2O2(+)·Cl(-), exhibits twofold rotational disorder in its cations with unequal occupancies.
• The differing rotational disorder prevents the formation of a centrosymmetric space group, resulting in a non-centrosymmetric lattice.
• Molecules are arranged in layers parallel to specific crystallographic planes, linked by hydrogen bonds.

Conclusions:

• The observed non-centrosymmetric lattice is a direct consequence of the unequal rotational disorder within the cations.
• The crystal structure is stabilized by a network of hydrogen bonds, including O-H⋯Cl⋯H-O motifs, and other interactions like C-H⋯Cl and C-H⋯N.
• This detailed structural analysis provides insights into the relationship between molecular disorder and macroscopic crystal properties.