Methyl side-groups control the Ia3̄d phase in core-non-symmetric aryloyl-hydrazine-based molecules

Control of the formation of liquid crystalline Ia3̄d gyroid phases and their nanostructures is critical to advance materials chemistry based on the structural feature of three-dimensional helical networks. Here, we present that introducing methyl side-group(s) and slight non-symmetry into aryloyl-hydrazine-based molecules is unexpectedly crucial for their formation and can be a new design strategy through tuning intermolecular interactions: the two chemical modifications in the core portion of the chain-core-chain type molecules effectively lower and extend the Ia3̄d phase temperature ranges with the increased twist angle between neighboring molecules along the network. The detailed analyses of the aggregation structure revealed the change in the core assembly mode from the double-layered core mode of the mother molecule (without methyl groups) to the single-layered core mode. Such changes are explained in terms of modified intermolecular interactions in those phases employing quantum chemical calculations.