Resorcinarene functionalized azo-based macrocyclic systems for nematic liquid crystalline behavior and photo tuning reversible properties

[Display omitted] •Novel tetramethoxy resorcinarene based liquid crystalline compounds are designed and characterized.•The azo-based macrocycles exhibited enantiotropic type mesomorhpic properties.•All four macrocyclic compounds showed nematic type liquid crystalline properties.•Detailed exploration of structure–property relationship elucidating the impact of alkyl chain on LC behavior.•The compounds exhibited photo switching reversible liquid crystalline properties. Four new macrocycles (TMRA1-TMRA4) based on resorcinarene core functionalized with azo-ester linking groups were successfully synthesized and characterized. The mesomorphic property of the macrocycles was investigated using polarizing optical microscopy and differential scanning calorimetry techniques. Further, the decomposition behavior of the azo mesogens was investigated by thermogravimetric analysis. All four resorcinarene-appended azo materials with variable alkyl arm exhibited enantiotropic nematic mesophase with a broad temperature range and higher thermal stability. The aim of the study was to establish a structure–property relationship to understand the effect of varying alkyl chains on the liquid crystalline properties. The photoswitching properties of the compounds demonstrated trans to cis isomerization in approximately 10 s, while the reverse process took nearly 4 h to return it to its original form. The nematic mesophase of compound TMRA1 was destroyed by isomerization due to the influence of asymmetrical mixture of both cis and trans isomers. Notably, the reversible liquid crystalline behavior of the compound TMRA1 before and after cis/trans isomerization displayed good reversibility.