Investigation on two homologus series of ferroelectric hydrogen bond liquid crystals derived from camphoric acid and alkyloxy/alkyl benzoic acids

•All the eight homologues of ferroelectric hydrogen bond liquid crystals isolated exhibit C* smectic ordering.•Dielectric studies in C* ordering of CA+9BAO indicate a Cole-Davidson mechanism•Presence of oxygen atom enabled abundance of mesogenic phases and inducement of smectic X*, a new smectic ord...

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Veröffentlicht in:Journal of molecular structure 2021-05, Vol.1231, p.129678, Article 129678
Hauptverfasser: Mohan, M.L.N. Madhu, Pal, Kaushik
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Sprache:eng
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Zusammenfassung:•All the eight homologues of ferroelectric hydrogen bond liquid crystals isolated exhibit C* smectic ordering.•Dielectric studies in C* ordering of CA+9BAO indicate a Cole-Davidson mechanism•Presence of oxygen atom enabled abundance of mesogenic phases and inducement of smectic X*, a new smectic ordering Two ferroelectric series comprising of 12 mesogens are investigated. In the first homologous series, Camphoric acid abbreviated as CA which is a ferroelectric ingredient, formed hydrogen bonds with benzoic acids with oxygen atom abbreviated as nBAO. The carbon chain of the benzoic acids varied from 5 to 12 atoms. Thus eight homologous members are synthesized. This mesogenic homologous series is represented as CA+nBAO. Similarly, Camphoric acid formed hydrogen bonds with alkyl benzoic acids abbreviated as nBA. The carbon number of the benzoic acids varied from 5 to 8. This mesogenic homologous series is represented as CA+nBA. Phases observed includes a new phase variant Smectic X*, and conventional phases C*, I* and G*. DSC thermograms exposed the Tc and corresponding ΔH magnitudes. Dielectric relaxations in smectic C* are discussed for a selected mesogen. The existence of oxygen in CA+nBAO facilitated presence of abundance poly phase morphism. [Display omitted]
ISSN:0022-2860
1872-8014
DOI:10.1016/j.molstruc.2020.129678