Chirality from Achiral Liquid Crystals
Principal investigator
Nowadays, liquid crystalline materials are best known for their successful implementation in flat panel displays, and yet they exhibit a plethora of peculiar properties that offer enormous potential for fundamental science as well as innovative applications well beyond the displays sphere. The proposal addresses a fast-developing area of liquid crystal science in which bulk, helical arrangements are formed from constituents, which are not themselves chiral. The current proposal arises from previous work in which it was shown that flexibly linked, dimeric molecules may also exhibit this general behaviour. According to the theoretical model, the arrangement does not require molecular chirality, instead it can be facilitated simply by the shape of bent molecules. Among great number of studied dimers, only a few achiral odd-memebered dimeric molecules displayed an unusual nematic phase with helical molecular organization. Such an observation is unprecedented and the current proposal seeks to delineate the central structure/property correlations and expand the number of such materials available. The work proposed herein envisages synthesis and mesomorphic characterisation a range of novel symmetric dimers having modifications on all relevant structural moieties in order to unravel their role in molecular arrangement within the liquid crystalline state. Conformational analysis using DFT calculation will provide information on geometrical and electronic effects influencing molecular packing while NMR investigation of selected neat dimers will enable direct insight into intermolecular interactions within the phase. Thus, combined experimental, computational and spectroscopic studies will provide valuable information on structural and electronic factors influencing formation and stability of helical self-assembly and expands the possibility for controlled fabrication of novel materials for various applications ranging from micropower generators to artificial muscle.