A density functional theory-based exploration of structure–property relationships in fluorinated antiferroelectric liquid crystal compounds

This study presents a comprehensive density functional theory investigation of a homologous series of chiral smectic liquid crystalline compounds, denoted as nF6R (n = 1–6), featuring fluorinated terminal chains and a rigid biphenylyl benzoate core. The research aims to elucidate the influence of perfluorinated chain length on the structural, electronic, thermodynamic, and nonlinear optical properties of these compounds. Employing the B3LYP/6-311G(d, p) level of theory, we optimized molecular geometries, calculated frontier molecular orbital energies, reactivity descriptors, thermodynamic parameters, and simulated Raman spectra. Key findings reveal a systematic increase in dipole moment, polarizability, and vibrational complexity with chain length, alongside consistent highest occupied molecular orbital– lowest unoccupied molecular orbital energy gaps, indicating preserved core electronic properties. Notably, the 2F6R compound exhibited the highest first-order hyperpolarizability, underscoring its potential in second-order nonlinear optical applications. The calculated thermodynamic data highlight enhanced entropy and thermal stability in longer-chain homologues, supporting their suitability for advanced electro-optical and photonic device integration.