Synthesis and Characterization of Quinuclidinium Derivatives of the [closo-1-CB11H12]− Anion as Potential Polar Components of Liquid Crystal Materials

• Published in: Inorganic chemistry 2016-04, Vol.55 (8), p.4016-4025
• Main Authors: Pecyna, Jacek, Kaszyński, Piotr, Ringstrand, Bryan, Pociecha, Damian, Pakhomov, Serhii, Douglass, Andrew G, Young, Victor G
• Format: Article
• Language: English
• ISSN: 0020-1669; 1520-510X
• DOI: 10.1021/acs.inorgchem.6b00319

Antipodal substitution of the [closo-1-CB11H12]− anion with a 4-pentylquinuclidinium fragment and alkyl groups in positions C(1) and B(12) gave polar zwitterions 1­[n] and 2­[n]. The molecular structure of 1­[5] was established using X-ray diffraction (XRD) methods: P1̅, a = 15.162(2) Å, b = 16.546(3) Å, c = 19.794(3) Å; α = 84.871(2)°, β = 84.057(2)°, γ = 84.058(3)°; Z = 8. All compounds exhibit high temperature in-plane ordered smectic phases that are stabilized by dipolar interactions. The ordered phases were investigated by powder XRD methods. Thermal and dielectric parameters for two derivatives, 1­[0] and 1­[6], were evaluated in nematic hosts, ClEster and BPhF. The dielectric data were analyzed with the Maier-Meier formalism augmented with density functional theory methods, and the results were compared to those for similar zwitterions previously reported.