Indian Journal of Science and Technology

Abstract

Cobaloximes of the types Trans– BH2[Co(dmgH)2X] , where dmgH- = Dimethylglyoximate, X- = Cl- or Br- and Trans–[Co(dmgH)2(H2O)I].B where, B = Piperazine (Pp) or 2-(N-Tert-butylamido)piperazine (tBu-PpAM) were prepared and characterized by TG/DTA, FABMS UV-visible, IR, NMR spectra and XRD studies. All the cobaloximes were screened against microorganisms for their antimicrobial activity and compared with streptomycin as standard. The free ligands viz., Pp & tBu-PpAM, showed antimicrobial activity in the order: Pp < t-Bu-PpAM. Most of the cobaloximes were found to be more active than the corresponding ligands such that the antimicrobial activity order for the axial halides was found to be Cl- > Br- > I - for cobaloximes having piperazine where as in the case of cobaloximes having 2-(N-Tertbutylamido)piperazine the antimicrobial activity order was found to be reversed as Br - > Cl- >I- .
Keywords: Cobalt(III) complexes, cobaloximes, antimicrobial activity of cobalt (III) complexes.