Mesomorphic and DFT studies of terminal ester containing salicylaldimines and their copper (II) complexes

ABSTRACT

In this article, we report synthesis and characterization of a novel homologous series of butyl 4-(4′-(alkoxy)-2-hydroxybenzylideneamino)benzoates, C_nLH (n = 6, 8, 10, 12, 14, 16) and their copper(II) complexes. The mesomorphic properties of these compounds were investigated by differential scanning calorimetry (DSC), polarizing optical microscopy (POM) and powder X-ray diffraction (XRD) studies. The ligands and their copper(II) complexes exhibit wide range of enantiotropic smectic A mesophase as confirmed by their typical optical texture under polarizing microscope. Thermal stability of the compounds is determined by thermo gravimetric analyses. DFT calculations have been performed using GAUSSIAN-09 program at B3LYP level to obtain the stable electronic structure of the ligand and its copper(II) complex.

KEYWORDS:

• Copper complexes
• density functional theory
• metallomesogens
• salicylaldimine
• structure‒property correlation

Acknowledgments

HKS (Senior Research Fellow) is grateful to Council of Scientific and Industrial Research (CSIR), New Delhi, India, for providing research fellowship. BS is grateful to DRDO, India (Project No. ERIP/ER/1203053/M/01/1542) for financial assistance. The authors wish to thank Dr. Sandeep kumar and Ms. Vasuda, Raman Research Institute, Bangalore, India for the XRD analysis.