[closo-1-CB11H11-1-Ph]− as a structural element for ionic liquid crystals

• Derivatives of the [closo-1-CB11H11-1-Ph]− anion form SmA ionic liquid crystals (ILC).
• The mesophase is destabilized in derivatives of [closo-1-CB11H11-1-Ph]− relative to [closo-1-CB11H11-1-COOPh]−.
• Increasing the chain length increases the SmA phase stability and range.
• Structure–property relationships in ILC follow those found in non-ionic analogues.

Ion pairs 2[Pyr] and 3[Pyr] containing [closo-1-CB11H11-1-Ph]− as the structural element were synthesized and their liquid crystalline properties were investigated by thermal and optical methods. Their mesogenic behavior was compared to that of the analogous series 1[Pyr] having a COO linking group between the benzene ring and the cluster, and the observed structure–property relationships are discussed in the context of general trends in related non-ionic liquid crystals.

Ions pairs of anisometric anion, derived from [closo-1-CB11H11-1-Ph]−, and substituted pyridinium cation exhibit a SmA phase.Figure optionsDownload as PowerPoint slide