Ferroelectric nematogens containing a methylthio group.

Stepanafas, Gytis; Cruickshank, Ewan; Brown, Stevie; Majewska, Magdalena M.; Pociecha, Damian; Gorecka, Ewa; Storey, John M.D.; Imrie, Corrie T.

Abstract

The synthesis and characterisation of eight nematogens containing a terminal methylthio group is reported. The compounds are based on RM734 and differ in the number and position of fluorine substituents, and in the position of the lateral methoxy substituent. Seven of these compounds exhibit a monotropic ferroelectric nematic phase, NF, including examples of NF-isotropic phase transitions. Two of the compounds show the anti-ferroelectric NX phase. Their transitional behaviour is discussed in terms of molecular shape and changes in electronic properties. Their phase behaviour is similar to that of the corresponding compounds containing a terminal methoxy group, but the methoxy terminated materials consistently show the higher transition temperatures. This is accounted for by the larger reduction in molecular shape anisotropy associated with the methylthio group, and the associated change in the electronic properties. The NX phase seen for the methylthio substituted compounds are thought to reflect the suppression of the NF phase by the methylthio group rather than any specific stabilising effect. Specific interactions between methylthio groups thought to stabilise nematic behaviour do not appear to stabilise the NF phase.

Citation

STEPANAFAS, G., CRUICKSHANK, E., BROWN, S., MAJEWSKA, M.M., POCIECHA, D., GORECKA, E., STOREY, J.M.D. and IMRIE, C.T. 2024. Ferroelectric nematogens containing a methylthio group. Materials advances [online], 5(2), pages 525-538. Available from: https://doi.org/10.1039/d3ma00446e

• Journal Article Type: Article
• Acceptance Date: Oct 14, 2023
• Online Publication Date: Oct 16, 2023
• Publication Date: Jan 21, 2024
• Deposit Date: Oct 17, 2023
• Publicly Available Date: Nov 27, 2023
• Journal: Materials advances
• Print ISSN: 2633-5409
• Electronic ISSN: 2633-5409
• Publisher: Royal Society of Chemistry
• Peer Reviewed: Peer Reviewed
• Volume: 5
• Issue: 2
• Pages: 525-538
• DOI: https://doi.org/10.1039/d3ma00446e
• Keywords: Compounds; Molecular modelling; Differential scanning calorimetry; Dielectric spectroscopy
• Public URL: https://rgu-repository.worktribe.com/output/2113775
• Additional Information: This article has been published with separate supporting information. This supporting information has been incorporated into a single file on this repository and can be found at the end of the file associated with this output.