Polar Liquid Crystals Derived from Sulfonium Zwitterions of the [closo‐1‐CB11H12]– Anion

Abstract

A series of substituted 12‐sulfonium zwitterions 1[n] and one example of a 1‐sulfonium analogue 2[5]a were prepared in four steps. Derivatives 1[n] exhibit rich crystalline polymorphism and a high‐temperature SmBcry phase stabilized by dipolar interactions. Solution studies in a nematic host demonstrated positive dielectric anisotropy of compounds 1[5]a–1[5]c (Δε ≈ +18 extrapolated from 8 mol‐% solutions) resulting from a longitudinal electric dipole moment of ca. 9.5 D. The effectiveness of additives 1[5] was analyzed by using the Maier–Meier formalism and DFT methods and compared to those of more polar derivatives 3[6]a and Pyr[10].