Synergistic Investigation of Binary Hydrogen Bond Liquid Crystal Complex: Experimental and Theoretical (DFT) Perspectives of Smectic Molecular Ordering via Molecular Dynamics

Binary hydrogen bond liquid crystal (HBLC) complex is isolated from the combination of cholesteryl stearate (CHS) and 4-methoxycinnamic acid (4MCA) mesogenic compounds. Induced chiral smectic phases are observed and characterized using a polarizing optical microscope (POM). Enthalpy values and transition temperatures of liquid crystal (LC) phases and their thermal stability are reported using differential scanning calorimetry (DSC), and the same has been supported by the density functional theory (DFT) method. Observation of a strong peak at 3580 cm⁻¹ from the FTIR spectrum confirms the hydrogen bond (H-bond) between chiral (CHS) and non-chiral (4MCA) mesogenic compounds. Further, DFT calculation explores the molecular mechanism of the complexation (CHS + 4MCA). The calculated global reactivity parameters (GRP) values (DFT calculations) justify the stability of the synthesized binary HBLC complex (CHS + 4MCA). In addition, topological analysis of DFT confirms the intermolecular interaction in the title binary HBLC complex. Donor and acceptor interaction in the binary HBLC complex (CHS + 4MCA) is reported using molecular electrostatic potential (MEP) analysis. Further, the impact of increased H-bond length and bond angle on induced chiral smectic ordering has been discussed in the present communication. Quantum theory of atoms-in-molecules (QTAIM) study endorses the existence of linear H-bonding of O–H···O in the binary HBLC complex. In addition, the enhanced mesomorphic behaviour along with non-linear optical properties (NLO) is reported.

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