1-Benzyl-3-methyl-imidazolium bromide

Area of Science:

• Materials Science
• Crystallography
• Ionic Liquids

Background:

• Ionic liquids (ILs) are salts with low melting points, often remaining liquid at room temperature.
• Understanding the solid-state structure of ILs is crucial for predicting their properties.
• (BenzMIm)Br is an ionic compound with potential applications in various chemical processes.

Purpose of the Study:

• To determine the crystal structure of 1-benzyl-3-methyl-imidazolium bromide ((BenzMIm)Br).
• To investigate the intermolecular interactions within the solid state of (BenzMIm)Br.
• To correlate the observed crystal structure with the compound's physical properties, such as its melting point and liquid behavior.

Main Methods:

• Single crystal X-ray diffraction was used to elucidate the molecular and crystal structure.
• Crystallization was achieved directly from a pure, liquid sample of (BenzMIm)Br.
• Analysis of the crystal structure focused on cation-anion interactions and packing.

Main Results:

• The molecular structure of (BenzMIm)Br consists of discrete bromide anions and 1-benzyl-3-methyl-imidazolium cations.
• Cations and anions are connected through short C-H⋯Br hydrogen bonding interactions.
• The compound crystallizes in an orthorhombic unit cell containing two unique ion pairs in the asymmetric unit.
• A relatively low melting point of 72°C was observed, with the compound existing as a supercooled viscous liquid at ambient conditions.

Conclusions:

• The crystal structure of (BenzMIm)Br provides insights into its solid-state organization.
• The identified C-H⋯Br interactions play a role in stabilizing the crystal lattice.
• The low melting point and liquid behavior at room temperature are consistent with its ionic liquid nature.