Design of Novel Mesomorphic Compounds: N,N′,N″-Trialkyl-1,3,5-benzenetricarboxamides

Abstract

N,N′-Dialkyl-1,4-benzenedicarboxamides melt with anomalously small enthalpy changes. The 1,3-analogs behave similarly but at lower temperatures. These observations provide a clue to design novel mesomorphic compounds; N,N′,N″-trialkyl-1,3,5-benzenetricarboxamides. The compounds carrying pentyl to octadecyl groups melt at temperatures between 49 and 119 °C depending upon the alkyl chain length. The clearing points are located above 200 °C. The unoriented liquid crystals show X-ray diffraction patterns consisting of two major peaks. The inner sharp peak gives a spacing, which increases as the series is ascended, from 1.40 to 2.26 nm. The outer one is sharp in the pentyl and hexyl derivatives but diffuse in the higher homologous members. The second moments of the broad-line proton NMR spectra measured above the melting points are as small as a few hundredths G2 and firmly establish the liquid-like characteristics of the alkyl chains.

Columnar self-assembly of N,N′,N′′-trihexylbenzene-1,3,5-tricarboxamides investigated by means of NMR spectroscopy and computational methods in solution and the solid state

“…[3][4][5][6] These discotic systems [7] are characterized by a helical arrangement of units and have attracted attention as organic electronic elements due to their liquid crystal features. [8] Detailed studies of their aggregation process have highlighted the cooperative nature of these self-assemblies. [9,10] Derivatives of BTA have been investigated as MRI contrast agents, [11] metal complexation agents [12] and utilized in drug-delivery systems.…”

Tuning the Ferroelectric Properties of Trialkylbenzene‐1,3,5‐tricarboxamide (BTA)

“…[29,30] It has a π-stacking benzene core, three hydrogenbonding dipolar amide groups, and peripheral flexible alkyl chains for enhancement of solubility and liquid crystallinity (Figure 1a). Initially BTA has attracted a lot of interest due to structure-related strong intermolecular interaction and the resultant formation of supramolecular polymers in solution, the ability to create gels as well as rigid nanofibers.…”

Creep Behavior of a Maxwell Element Type Supramolecular Polymeric System

“…[12][13][14] Gelator molecules, such as trialkyl-1,3,5-benzenetricarboxamides, that possess 3-fold rotation symmetry are highly effective in the formation of supramolecular architecture, especially for the construction of one-dimensional, enormously long columnar supramolecular structures in non-polar media. [15][16][17][18][19][20][21][22][23][24] In this case, the formation of the supramolecular polymers is attributable to the strong intermolecular hydrogen bonding between the two amide groups of the side-chains. [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24] We have previously reported on the linear viscoelastic behavior under dynamic measurements at small shear strain amplitudes of supramolecular organogels involving gelators with 3-fold rotation symmetry, N, N', N"-tris (3,7-dimethyloctyl) benzene-1,3,5-tricarboxamide (DO 3 B) 25) and tris-3,7-dimethyloctyl cis-1,3,5-cyclohexane-tricarboxamide (DO 3 CH) 26) , in organic solvents with low viscosity, n-alkanes such as n-decane (C 10 ), at varying gelator concentrations (c).…”