Detailed analysis of induced smectic phases and paramorphic effect of double hydrogen bonded ferroelectric liquid crystals

A novel double hydrogen bonded ferroelectric liquid crystal (HBFLC) complex was isolated from (R)-(+)-Methylsuccinic acid (RMSA) and 4-Nonyloxybenzoic acid (9OBA). The presence of hydrogen bond between proton donor (RMSA) and proton acceptor (9OBA) molecules were characterized by FT-IR spectroscopy. Mesomorphic behavior and its phase transition temperature of the HBFLC complex (1:1 and 1:2 ratio) were studied by differential scanning calorimeter (DSC), polarized optical microscope (POM) and identified smectic A*, smectic C* and smectic G* phases by quenching of nematic. MSA + 9OBA HBFLC complex has strong dipole moment which is vertical to the lengthy molecular axis provide a pathway to the insight of smectic mesophases. Sm C* phase revealed paramorphic effect due to refractive index changes in the H-bond layers and leads violet to red color textures. Stabilization of the smectic phase by dipole-dipole interaction in the HBFLC complex was reported using density functional theory (DFT) analysis. Stability of the phase increase while increasing the mesogenic ratio in the present HBFLC complex was also discussed. The structure of the MSA + 9OBA HBFLC complex was optimized by B3LYP theory with the basis set of 6311-G (d, p). In natural bond orbital analysis, it was found that the high stabilization energy specified the intermolecular interaction among the molecules. [Display omitted] •Self assembly behavior and segregation effect induce the chiral smectogenic phases by quenching of nematic phase.•HBFLC complex shows iridescent colors with respect to the temperature and decreases the thermal stability of Sm C* phase.•Sm A* phase improves the molecular alignment which increases the phase stability in the HBFLC complex.•MSA + 9OBA HBFLC complex exhibit undistributed focal-conic texture is transformed into paramorphic behavior of Sm C* phase.•Sm A* phase and its paramorphic behavior of Sm C* phase is used for optical filters and photodiode applications.