Calixarene Functionalized Supramolecular Liquid Crystals and Their Diverse Applications

Liquid crystals are considered to be the fourth state of matter with an intermediate order and fluidity in comparison to solids and liquids. Calixarenes are among one of the most versatile families of building blocks for supramolecular chemistry due to their unique vaselike structure that can be chemically engineered to have different shapes and sizes. During the last few decades, calixarenes have drawn much attention in the field of supramolecular chemistry due to their diverse applications in the fields of ion and molecular recognition, ion-selective electrodes for catalysis, drug delivery, gelation, organic electronics and sensors, etc. Imbuing liquid crystallinity to the calixarene framework leads to functionalized calixarene derivatives with fluidity and order. Columnar self-assembly of such derivatives in particular enhance the charge migration along the column due to the 1D stacking due to the enhanced π-π overlap. Considering limited reports and reviews on this new class of calixarene based liquid crystals, a comprehensive account of the synthesis of calixarene liquid crystals along with their mesomorphic behavior and potential applications are presented in this review.

Columnar self-assembly, electrochemical and luminescence properties of basket-shaped liquid crystalline derivatives of Schiff-base-moulded p-tert-butyl-calix[4]arene

A new family of blue-light emitting supramolecular basket-shaped liquid crystalline compounds based on p-tert-butyl-calix[4]arene core to form self-assembly and columnar hexagonal phase.

Evaluation of Anticancer Activities of Novel Facile Synthesized Calix[n]arene Sulfonamide Analogs

Here, new calixarene sulfonamide analogs were synthesized from the reaction of chlorosulfonated calix[n]arene (n: 4, 6, and 8) with N,N'-dimethylethylenediamine or ethylenediamine for the first time and an excellent calixarene sulfonamide analog showing potent and selective cytotoxic activity on some cancer cell lines were discovered. Cytotoxicity of the prepared calix[n]arene sulfonamide analogs towards both cancer and healthy cell lines was assessed by performing cell growth inhibition assays. In cytotoxicity assay results, it was observed that while sulfonamide analog based calix[4]arene (9) was not affecting the growth of epithelial cell lines (HEK), and it was especially effective on inhibiting the growth of some human cancer cell lines (MCF-7 and MIA PaCa-2). These results highlight that sulfonamide analog-based calix [4] arene (9) can be further studied as a potential anticancer agent.

A new class of supramolecular liquid crystals derived from azo calix[4]arene functionalized 1,3,4-thiadiazole derivatives

A new class of bowl-shaped supramolecular liquid crystals (LCs) is described derived from calix[4]arene substituted with 1,3,4-thiadiazole derivatives, inbuilt with Schiff base and ester on the lower rim and with an azo group on the upper rim with an alkyl side chain (–OC₃H₇, –OC₈H₁₇).

Columnar self-assembly, gelation and electrochemical behavior of cone-shaped luminescent supramolecular calix[4]arene LCs based on oxadiazole and thiadiazole derivatives

A new class of blue light-emitting supramolecular liquid crystalline cone or bowl-shaped compounds were synthesized from substituted 1,3,4-oxadiazoles and 1,3,4-thiadiazoles with calix[4]arene derivatives.

Bowl-shaped fluorescent liquid crystals derived from 4-tert butyl calix[4]arene and trans cinnamic acid derivatives

A new family of bowl-shaped molecules with a calix[4]arene rigid core appended by four-side and two-side substitution with trans 4-n-alkoxy cinnamic acid has been synthesized and well characterized.

Columnar self-assembly of bowl shaped fluorescent liquid crystals based on calix[4]arene with Schiff base units

A new family of bowl-shaped molecules with a calix[4]arene rigid core and appended on four-sides, that display a wide range of hexagonal columnar phases, has been synthesised and well characterized.