1-Butyl-3-vinylimidazolium bromide is a specialty ionic compound used primarily as a monomer in the synthesis of polymeric ionic liquids (PILs). The ethenyl (vinyl) group allows for polymerization via free radical, controlled radical (e.g., ATRP, RAFT), or other methods, enabling the creation of functional polymers for applications in CO2 capture, ion-conducting membranes, energy storage devices, and actuators. It also serves as an intermediate or additive in catalytic processes, such as cross-coupling reactions or phase-transfer catalysis, where its ionic nature enhances solubility, selectivity, and recyclability. Unlike traditional solvents, its solid form (white to light yellow powder) makes it suitable for supported catalysis or polymer-bound systems in green chemistry.