The role of fluorine substituents in the formation of the ferroelectric nematic phase.

Cruickshank, Ewan; Walker, Rebecca; Strachan, Grant J.; Górecka, Ewa; Pociecha, Damian; Storey, John M.D.; Imrie, Corrie T.

Abstract

The synthesis and characterization of a group of molecules based on the skeletal structures of 4-[(4-nitrophenoxy)carbonyl]phenyl 4-methoxybenzoate and (4-nitrophenyl) 2-methoxy-4-(4-methoxybenzoyl)oxybenzoate is reported. Fluorine substituents are added to these structures and their liquid crystalline behaviour is characterised. All eight compounds reported exhibit the ferroelectric nematic phase, NF, and in four of them the antiferroelectric phase labelled NX is observed. These include rare examples of enantiotropic NF and NX phases, and several examples of the direct NF-isotropic transition. The addition of a fluorine substituent reduces the nematic-isotropic transition temperature, and this is attributed to the reduction in both shape anisotropy and the ability of the molecules to form antiparallel dimers. The effect of the fluorine substituents on the NF and NX phase is less regular and interpreted in terms of the changes to molecular shape and electron distribution. The stability of the NX phase follows that of the NF phase in the series without a lateral methoxy group. The addition of a lateral methoxy group reduces the stability of the NF phase and completely suppresses the NX phase.

Citation

CRUICKSHANK, E., WALKER, R., STRACHAN, G.J., GÓRECKA, E., POCIECHA, D., STOREY, J.M.D. and IMRIE, C.T. [2025]. The role of fluorine substituents in the formation of the ferroelectric nematic phase. Journal of materials chemistry C [online], Advance Article. Available from: https://doi.org/10.1039/D4TC03318C

• Journal Article Type: Article
• Acceptance Date: Dec 20, 2024
• Online Publication Date: Dec 20, 2024
• Deposit Date: Jan 13, 2025
• Publicly Available Date: Jan 17, 2025
• Journal: Journal of materials chemistry C
• Print ISSN: 2050-7526
• Publisher: Royal Society of Chemistry
• Peer Reviewed: Peer Reviewed
• DOI: https://doi.org/10.1039/d4tc03318c
• Keywords: Ferroelectric nematic phase; Fluorine; Lateral substituents; Liquid crystals; Nematic phase
• Public URL: https://rgu-repository.worktribe.com/output/2656276
• Additional Information: The file associated with this output includes supporting materials after the main text.