The preparation of [closo-1-CB9H8-1-COOH-10-(4-C3H7C5H9S)] as intermediate to polar liquid crystals

Zwitterionic pyridinium derivatives of [closo-1-CB9H10]−and [closo-1-CB11H12]−as high Δεadditives to a nematic host

“…1) have high dielectric anisotropy D3 and are useful additives to nematic materials for LCD. In this context, we developed a synthetic methodology and prepared 1-sulfonium 3,4 and 1-quinuclidinium, 3 and also 10-sulfonium [4][5][6] and 10-pyridinium 7 zwitterions, compounds of the general structure IIA and IA. Some of them exhibit nematic behavior and D3 reaching a record high value of 113.5(!)…”

Functionalization of closo‐Borates via Iodonium Zwitterions

“…Ester 20‐ p , the parent compound of a class of polar liquid crystals,4c was obtained in higher yield (81 %) from the isomerically pure carboxylic acid 8 c‐ p (Table 3, entry 1). This result again represents a significant improvement over the previous method 22. A similar reaction of the phenyliodonium species 11 a‐ p with thian gave the sulfonium derivative 22‐ p in moderate yield (30 %; Table 3, entry 3), along with a product presumably derived from cage arylation with PhI.…”

“… [a] Typical conditions: The iodonium zwitterion (1.0 mmol) and the appropriate reagent (2 mL) were stirred at 55–100 °C. [b] The product was isolated after treatment with CH 2 N 2 22…”

Investigation of high Δεderivatives of the [closo-1-CB9H10]−anion for liquid crystal display applications

“…4 [3]e and 4 [3]f, were obtained from the corresponding acid chloride and excess cyclohexanols 11 in neat pyridine. The sulfonium acids 9[3], 8 9[5], 5 and 9 [7] were prepared by thermolysis of the methyl ester of diazonium acid 12 (ref. 8 and 9) in the presence of the appropriate thiane 13[n] (ref.…”