Macrocyclic ligand - cobalt (III) complex of liquid crystal for future applications

Thermally stable macrocyclic transition metal containing liquid crystals (metallomesogens) have garnered attention for their remarkable properties and potential applications across diverse scientific domains. These self-organizing liquid crystals with thermotropic transitions are excellent mtallomesogens where functional properties of the transition metals such as magnetic criteria, charge conduction ability, redox, or luminous property are combined with the porous structure and wide-ranging surface area of macrocycles. This association leads to the formation of substances with promising applications across various smart electronic devices, spanning from optical displays, to drug delivery, and energy storage and conversion systems. This study presents the synthesis, structural analysis, and evaluation of thermal and mesomorphic characteristics of a cobalt-based macrocyclic metallomesogen, [Co(Clm)(Dec)₂].(Dec); where Clm denotes cyclam (1,4,8,11-tetraazacyclotetradecane) and Dec represents 4–decyloxybenzoate (4-CH₃(CH₂)₉OC₆H₄COO-). Although single-crystal X-ray diffraction was unsuccessful due to challenges in crystal growth, the coordination geometry of the trans-III Co(III) ion that was distorted octahedral was deduced through elemental examination, spectra obtained from UV–visible range absorption, Fourier-transform infrared (FTIR) spectroscopy, magnetic susceptibility measurements at ambient temperature, and thermogravimetric analysis (TG). The ambient temperature magnetic susceptibility discovered a magnetic moment of 0.60 BM., distinctive of diamagnetic low spin Co(III) in octahedral geometry. Thermal analysis by TG found good thermal stability, with disintegration initiated at 229 °C. Transitions of phase were perceived through DSC, and the representative optical textures were investigated by means of POM (Polarizing Optical Microscope); that exhibited growth of battonet textures typical for smectic mesophase.