Synthesis, micellar properties, DNA binding and antimicrobial studies of some surfactant-cobalt(III) complexes

A new class of surfactant-cobalt(III) complex ions of the type, cis-[Co(X)2(C14H29NH2)Cl]2+ (where X = ethylenediamine (en), or 2,2'-bipyridyl (bpy), or 1,10-phenanthroline (phen)) and cis-[Co(trien)(C14H29NH2)Cl]2+ (trien = triethylenetetramine) were synthesized and characterized by IR, NMR, UV-visible electronic absorption spectra, elemental analysis and metal analysis. The critical micelle concentration (CMC) values of these surfactant-cobalt(III) complexes in aqueous solution were obtained from conductance measurements. Specific conductivity data (at 298, 308, 318 and 328 K) served for the evaluation of the temperature-dependent CMC and the thermodynamics of micellization (ΔG0m, ΔH0m and ΔS0m). Interactions between calf thymus DNA and the surfactant-cobalt(III) complexes in aqueous solution have been investigated by electronic absorption spectroscopy, emission spectroscopy and viscosity measurements. The electrostatic interactions, van der Waals interactions and/or partial intercalative binding have been observed in these systems. The surfactant-cobalt(III) complexes were screened for their antibacterial and antifungal activities against various microorganisms. The results were compared with the standard drugs, Ciprofloxacin and Fluconazole respectively.