Coumarin derivatives containing schiff base and ester mesogenic core: Synthesis, mesomorphic behaviour and DFT calculations

Quantum Chemical Investigation of Thermotropic Ionic Liquid Crystals to Predict Phase Transition Temperatures

“…There are primarily three parts to consider when building a new TILC material: the promesogenic group or mesogenic core unit (a rod-like mesogenic core which primarily makes the molecule into a liquid crystal); the linker, bridge or spacer group (which affects length, flexibility and adjusts mesomorphosity); and the functional, terminal group or moiety (which determines additional functionality, such as ionicity). 11,12,[24][25][26] This structure division is displayed in Figure 6. For electrolyte purposes, it is desirable that the molecule is amphiphilic, so the functional group end is ionophilic and the promesogenic group end is ionophobic.…”

“…Other groups such as ester, azo, ether, unsaturated bonds, azomethine are used, depending on the desired length, geometry, linearity, rigidity, anisotropy and lipophilicity of the final product. 25,26,[29][30][31][32] For example, azomethine and ester linker groups have strong polarity and rigidity. Using these can improve mesomorphic properties of the TILC because of the stronger intermolecular interactions exerted by these linkers.…”

“…[33][34][35] A linker that enhances molecular linearity (be it linear itself, or stepped) raises the overall TILC stability and enhances mesogenic formation. 25,26,[36][37][38][39][40][41] The functional group is chosen based on what kind of functionality is wanted for the TILC. For the purpose of being an electrolyte, it is desirable for it to facilitate the transportation of Li + as well as possible.…”

“…DFT in particular has been well received and proven to be an excellent technique for estimating properties such as molecular geometries, orbital energies, energy gaps, and more with exceptional performance and reliability. 26,[145][146][147] Using computation has the potential to significantly accelerate the development of new materials and molecules, however in present times it is primarily used to post-rationalize experimental observations, though efforts are being made to change this. 45 To predict any material at the microscopic level, one inevitably has to tackle the phenomena described in quantum mechanics, and thus solving the Schrodinger's equation.…”