Heterodimeric hydrogen-bonded mesogens comprising pyridine moiety: a review

Hydrogen bonding plays an important role in building the super-structures in chemical and biological systems because of its specificity and directionality. In this context, significant works have been conducted recently to study the role of hydrogen bonding interactions in the formation and/or stabilization of mesophases. Also, this flexible and active non-covalent interaction has been widely utilized in other fields such as self-assembly, crystal engineering, polymer chemistry and nanotechnology. However, hydrogen bond interactions have emerged in recent years as a tunable supramolecular synthetic method with adjustable phases and properties in the design of efficient liquid crystalline materials. The present critical review describes the preparation of various pyridine-based hetero-dimeric hydrogen-bonded mesogenic complexes, which were reported over the last 10 years and are mainly made of calamitic, bent, discotic and polymers. Also, it covers the structure, mesophase stability, role of various terminal/lateral substituents, and future perspectives of these complexes. GRAPHICAL ABSTRACT