Fluorinated twist-bend nematogens: the role of intermolecular interaction
Anamarija Knežević, Irena Dokli, Jurica Novak, Darko Kontrec, Andreja Lesac
Abstract
New ethenyl-linked dimers which differ in the fluorine-substitution pattern were prepared and characterised. The investigation has been focused on the impact of electronic structure and non-covalent interactions associated with the presence of C-F bond on the stability of the NTB phase and overall thermal behaviour of the dimers. A joined computational and spectroscopy study showed that electrostatic interactions associated with C-F bond govern the conformational diversity of the mesogenic core without interfering with the molecular shape. The qualitative analysis of allowable inter-molecular interactions suggested that conformational diversity and flexibility of the fluorinated fragment influence the strength of intermolecular interactions and thus transitional properties, including stability of the NTB phase. These results provide an important insight into the relationship between the electronic structure, the strength of intermolecular interactions and transitional properties, providing a valuable contribution to the design of novel functional materials.