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

Abstract

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.

New Class of Supramolecular Bowl-Shaped Columnar Mesogens Derived from Thiacalix[4]arene Exhibiting Gelation and Organic Light-Emitting Diodes Applications

“…The obtained compound 3 is further reacted with phosphorous pentasulfide (P 2 S 5 ) to give the thiadiazole derivative ( 4 ). 46 On further heating to compound 4 in the presence of anhy. AlCl 3 in benzene resulted in compound 5 .…”

“…46 Compound 5 was coupled with different alkyl bromides to get compound 6a–6c . 46 Further, the oxidation of compound (6a–6d ) was carried out with chromyl chloride in the presence of pyridine and dichloromethane (DCM) to form compounds ( 7a–7d ). 46 The Schiff-base derivatives ( 8a–8d ) were formed by the reaction of compound ( 7a–7d ) with 2,4-dihydroxy aniline.…”

“…46 Further, the oxidation of compound (6a–6d ) was carried out with chromyl chloride in the presence of pyridine and dichloromethane (DCM) to form compounds ( 7a–7d ). 46 The Schiff-base derivatives ( 8a–8d ) were formed by the reaction of compound ( 7a–7d ) with 2,4-dihydroxy aniline. 47 Base-catalyzed condensation of 4- tert -butyl phenol and sulphur powder (S 8 ) in the presence of tetraethylene glycol dimethyl ether in a single step to obtain 4- tert -butyl thiacalixarene ( 9 ) is depicted in Scheme 2.…”

“…40−44 Among them, our research group also reported various calix[4]arene-based hexagonal columnar LCs with good photophysical behavior. 45,46 Marcos et al reported calix[4]arene-based mesogens inbuilt with the Schiff base linking unit. 47…”

Self‐Assembly of Bowlic Supramolecules on Graphene Imaged at the Individual Molecular Level using Heavy Atom Tagging

“…The calix[n]arenes, cyclic arene oligomers with n repeating units, in particular present the ability to complex with various ions and neutral guests, [13][14][15][16][17] opening up opportunities for developing responsive and switchable ferroelectric devices. While these bowlic mesogens have been widely investigated via thermal analysis and optical mesophase imaging, which often leads to the columnar, [13,18,19] smectic, [20][21][22] or nematic [20,22] mesophase assignments, any clear understanding of bowl-to-bowl packing has remained a challenge due to the shortage of direct structural analysis such as X-ray crystal structures. Some of the reported crystal structures illustrate head-to-head arrangement of bowls facilitated by CH•••π interactions for corranulenes, [23,24] dipolar interactions for sub-phthalocyanines, [25] and H-bonding among the hydroxy groups on the narrower rim (i.e., the lower rim by convention) of calix[n]arenes.…”