Maximizing Polarizability with Zwitterions

Covalently bonding cations and anions into a single small molecule called a zwitterion, results in an exceptionally large dipole that is controlled by the length of the spacer between anion and cation. While commercially available zwitterions have high melting points, we find that adding ethylene oxide units to the tail of an imidazolium cation greatly lowers the melting point far below ambient, resulting in zwitterionic liquids near room temperature with very large dielectric constants. Effects of anions with delocalized charge will also be discussed.