Mesophase behavior of a homologous series of fluorene–ester mesogenic compounds
Journal of Molecular Structure, vol.1360, 2026 (SCI-Expanded, Scopus)
- Publication Type: Article / Article
- Volume: 1360
- Publication Date: 2026
- Doi Number: 10.1016/j.molstruc.2026.145630
- Journal Name: Journal of Molecular Structure
- Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Chemical Abstracts Core, Chimica, Compendex, INSPEC
- Keywords: Blue phase, Calamitic, Ester linker, Fluorene, Liquid crystal, Mesophase
- Yıldız Technical University Affiliated: Yes
Abstract
A homologous series of fluorene-based mesogens featuring ester linkages, variable terminal alkyl chains, and systematically modified aromatic cores was synthesized to probe structure–mesophase relationships. Differential scanning calorimetry and polarized optical microscopy confirmed liquid-crystalline behavior throughout the series. Molecular-level tailoring of fluorene–ester architectures enables precise control of mesophase organization: increasing alkyl chain length and extending the aromatic core drive a transition from nematic to smectic A order. The shortest-chain compound (n = 8) exhibits a nematic phase, whereas longer homologues (n = 10–14) with longer alkyl chains cores stabilize the smectic A phase. Thermal analysis shows a slight reduction in clearing temperature with chain elongation, while the Cr–SmA transition remains low and nearly invariant, reflecting the balance between core rigidity and flexible chain packing. Incorporation of a chiral citronellol terminal group induces a chiral nematic phase and a distinct blue phase, highlighting the strong coupling between molecular structure and chirality in fluorene-based liquid crystals.