Polar derivatives of [closo-1-CB9H10]− and [closo-1-CB11H12]− anions as high Δε additives to a nematic host: a comparison of the CH2CH2 and COO linking groups. Issue 10 (25th February 2021)

• Record Type: Journal Article
• Authors: Jakubowski, Rafał; Pecyna, Jacek; Ali, Muhammad O.; Pietrzak, Anna; Friedli, Andrienne C.; Kaszyński, Piotr
• Is Part Of: Dalton transactions. Volume 50:Issue 10(2021)
• Page Start: 3671
• Page End: 3681
• Publication Date: 2021-02-25
• Subjects: Chemistry, Inorganic -- Periodicals; Chemistry, Physical and theoretical -- Periodicals; Chemistry, Inorganic -- Periodicals; 546.05
• DOI: 10.1039/d1dt00211b
• Languages: English
• ISSNs: 1477-9226

Abstract

Abstract : Liquid crystalline pyridinium zwitterions of [ closo -1-CB9 H10 ] − perform better as polar potential components of LCD materials than the sulfonium or [ closo -1-CB11 H12 ] − analogs on the basis of solubility and Maier–Meier analysis. Abstract : A series of liquid crystalline pyridinium and sulfonium derivatives of the [ closo -1-CB9 H10 ] − and [ closo -1-CB11 H12 ] − anions containing the CH2 CH2 linking group was prepared and their molecular and crystal structures were determined by single crystal XRD methods. Thermal and dielectric properties of the series were evaluated in a weakly polar nematic host. The highest extrapolated dielectric anisotropy, Δ ε, was observed for pyridinium zwitterions (up to 56.0). The dielectric data were analyzed with the Maier–Meier formalism augmented with density functional theory calculations, and the results were compared to those obtained for the analogous ester derivatives (COO linking group). The effect of the linking group on thermal and electrooptical properties is discussed.