Mesomorphic and computational evaluation of C N‧‧‧I halogen bonded complexes of 4-alkoxy-4′-cyanobiphenyls systems with 1,6- diiodoperfluorohexane

Thermotropic halogen bonded (XB) liquid crystalline complex (A-n XB) of 4-alkoxy-4′- cyano biphenyls (A-n) systems containing nitrile (-CN) group with variable alkoxy chain length (-CnH2n+1, where n = 3 to 10) acting as halogen bond acceptor with 1,6-diiodoperfluorohexane, (I-atom) acting as halogen bond donor were prepared by the liquid-assisted grinding method. The A-n XB complex formations, through CN‧‧‧I XB interactions, were established by the FTIR, Raman, PXRD, polarizing optical microscope (POM) with hot stage, DSC and TGA techniques. Further, POM study of these homologous XB complex series showed liquid crystalline phases with a alteration of (1–10 °C) compared to their respective parent mesogenic molecules. The computational study was carried out using Frontier Molecular Orbitals (FMOs), Molecular Electrostatic Potential (MEP), Non-covalent interactions (NCI) and Quantum theory of atoms in molecule (QTAIM) analysis to evaluate the reactivity parameters and strength of XB in the complexes.