Effect of shape and nano-segregation in Δ²-isoxazoline and isoxazole on the mesogenic behavior of 1,3-bis-isophthalimines

ABSTRACT

Bis-1,3-isophthalimines flanked by two side 3-aryl-5-perfluoroalkylisoxazoline or 3-aryl-5-perfluoroalkylisoxazol arms were produced and liquid crystal properties were analysed. Monotropic smectic A mesophase was found for bis-1,3-isophthalimines containing the 3-aryl-5-perfluorooctylisoxazoline (8b). Thermal behaviour was analysed and discussed by DSC, POM, DFT calculations, cohesive energy density (CED), Hildebrand solubility parameters and molecular-shape features. Notably, for long side arm perfluorooctyl 8b, the reduced value of CED is partially compensated by molecular shape of the molecules in the condensed state favouring the SmA mesophase formation.

GRAPHICAL ABSTRACT

KEYWORDS:

• Isoxazolines
• isoxazoles
• bis-1,3-isophthalimines
• semifluorinated liquid crystals
• (2+3)-cycloaddition

Acknowledgments

This work was supported by the CNPq/Edital Bolsa de produtividade Ed 09/2020 grant n° 309661/2020-0 and NSF agency. R. R. da Rosa thanks CAPES (Coordenação de Aperfeiçoamento de Pessoal de Nível Superior) [Finance Code 001] - Programa de Doutorado Sanduíche no Exterior - 88881.133963/2016-0 and NSF for financial support. Authors thanks Dr Julio Vaghetti for DSC facilities at LAMAT, IQ, UFRGS.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Author contributions

Conceptualization, A. A. M. and R. R. da R.; methodology, R. R. da R., C. S. B. W., R. A. P. H. and D. M. W.; software, P. R. L., A. A. M., I. G. and V. L.; formal analysis, A. A. M., D. M. W., R. R. da R. and I. G.; investigation, A. A. M.; R. R. da R., C. S. B. W., R. A. P. H; theoretical calculation P. R. L., V. L. and I. G.; writing-original draft preparation, A. A. M. writing-review, R. R. da R., D. M. W.; I. G. and A. A. M.; project administration, A. A. M.; funding acquisition, A. A. M. All authors have read and agreed to the published version of the manuscript.

Additional information

Funding

This work was supported by the CNPQ [Bolsa de produtividade Ed 09/2020 grant n° 309661,PDSE 88881.133963/2016-0].