Influence of complementary hydrogen bonds on mesogenic phases in ternary hydrogen bond liquid crystal complexes: experimental and theoretical approach

A ternary hydrogen-bond liquid crystalline complex is formed from compounds of 1,3-Phenylenediacetic acid, 4-(Octyloxy)benzoic acid and 4-Methoxycinnamic acid. The characteristic -OH (3554 cm−1) and C=O (1681 cm−1) stretching bands suggest complementary hydrogen bond formation. POM and DSC analyses revealed induced mesophases and its corresponding phase transition temperatures along with enthalpy changes. MEP analysis identified probable interaction sites, while IRI and IGMH analyses confirmed non-covalent interactions. Notably, the first-order hyperpolarizability is 57.68 times higher than that of urea, indicating enhanced NLO response. These findings enlighten the role of H-bonding in governing the mesomorphic and electronic properties of the ternary HBLC complex.