Sonochemical synthesis, characterization, antimicrobial activity and textile dyeing behavior of nano-sized cobalt(III) complexes

Using ultrasonic irradiations, nano-sized cobalt(III) coordination complexes, [Co(NH3)6]Cl3·2H2O (A), [Co(en)3]Cl3·3H2O (B) (en-ethylenediamine) and [Co(dien)2]Cl3·3.5H2O (C) (dien-diethylenetriamine) were synthesized. These complexes were characterized by spectroscopic studies like IR, UV/Visible and NMR. Morphology of these complexes was determined by SEM and particle size with the help of TEM & Zeta-sizer. The comparative thermal stability along with phase difference between nano structures and their respective bulk complexes has been studied by thermal gravimetric analysis (TGA) and X-ray powder diffraction (XRD) study respectively. The dyeing behavior of nano-sized Co(III) complexes and their respective bulks has also been studied (using both exhaust and pad dyeing methods) on cotton and wool fabrics and results shown rationalized dyeing behavior. All these complexes were further tested for antimicrobial activity (against B. subtilis, E. coli, K. pneumoniae, F. oxysporum and A. alternate) and it was observed that nano sized complexes enhanced the activity further.