Design, Synthesis, And Supramolecular Properties Of Benzene-1,3,5-Tricarboxamide Derivatives

Future development of chemistry focuses on collectivity realized by complex molecular systems. Supramolecules are bound together through weak interactions between molecules each other and are characterized with well-=definedmicrostructures and macroscopic properties. They serve as a key bridge between the molecularworld and physicalworld. Chirality is an asymmetric spatial structure in each substance all over the world. It is an equilibrium state of force in the environment of molecules. It is a basic property which describes the action and reaction within the surroundings. We attemptto probe into the formation rules of complex molecule system from the perspective of supramolecular chirality. The structure of BTA issimple and synthetically easy, but widely applied in supermolecular self-assembly as a module owing to its excellent properties. Based on the BTA model, we designed and synthesizeda novel molecule BTQ(Tris(quinoline-12-carboxylic acid methyl ester) Benzene-1,3,5-tricarboxamides).We foundthe interesting properties of BTQ derivatives in terms of symmetry breaking, chiral induction, and supramolecular assembly and so on.In addition, BTQ derivatives showed potential applications, such as dispersion of carbon nanotubes(for separation of chiral carbon nanotubes)and supramolecular gel materials.1. Synthesis of BTQderivatives and chirality-relatedpropertiesIn recent decades, research on chirality has made great progress. However, the homochirality of living system still kept debating on its origin. In molecular world, molecule racemization resulted in the difficulty of symmetry breaking. Therefore, chiral separation and amplification remain challenging in the research area of chirality. Herein, we synthesized anew type of BTQderivatives. Significantly, BTQ molecule is capable of spontaneously generating symmetry breaking in a solvent mixture, which offers usefulinsightonthe understandingof origin of chirality. Chirality amplificationis a very interesting phenomenon in supramolecular chemistry. A small amount of chiral molecules are capable of inducing achiral molecules, resulting in the formation of high-level chirality. Chiral molecules of1%can achieve the amplification of chirality as reportedpreviously. It is noteworthy that, achiral BTQmolecules usedin our study can realize the chirality amplification in the presence of 0.01 mol% chiral BTQ derivative, which is the strongest amplification with the smallest proportion so far. We characterized the BTQ molecule system with a set of spectral analysis techniques. 1H NMR and 13 C NMR are applied to identify the amount and structural information of atoms H and C. Infrared absorption spectrum is used to analyze the absorption peak of molecule properties and identify the information of molecule structure. Mass spectrum is applied to ascertain the molecule weight. Molecule crystal lattice parameters are obtainedby XRD test.Ultraviolet absorption spectrum is used to identify the aggregation state of the system. Circular dichroism is resorted to characterize themolecule chirality. Our results demonstrated the importantstructure-relatedand chiral properties in BTQ molecule system.2. Supramolecular assembly and functions of BTQderivativesWe modifiedthe BTQ molecule with chiral methylbenzylamine and glutamic acid derivatives and realized the chiral induction. In addition, with the help of computer simulation techniques and a series of spectralcharacterizations, chiral induction has proved to be successful.The derivatives of BTQ molecule are chiral molecules which are stabilizedby noncovalentinteractions including intramolecular hydrogen bonding, Van der Waals’ force, etc. By exploring internal factors like concentration, constituents, and external factors like temperature, solvent, we have discovered the favorable condition where supramolecular self-assembly can take place, resulting in the generation of advanced supramolecular helical structures. Characterizations including optical microscope, SEM and TEM, are usedto prove the supramolecular structures. At the same time, we explored the properties of BTQ and its derivatives in dispersing and collecting carbon nanotubes and studied their gelling conditions.This BTQ moleculesystem provided an excellent example for understanding the rule from molecular detailsto supramolecular chirality, which will possibly haveextensive prospects insome applications such as chiral separation of carbon nanotubes, supramolecular gel materials, and more.