Copper(II) complexes of tridentate N,N,N′,N″,N″-pentamethyldiethylenetriamine: Superoxide dismutase and inhibitory activity against bacteria and fungi

A series of ternary copper(II) complexes containing same coordination sphere but difference in the counter ions, viz., [Cu(PMDT)(OAc)]PF6(1); [Cu(PMDT)(OAc)]ClO4(2); [Cu(PMDT)(OAc)]BF4(3) and [Cu(PMDT)(OAc)]BPh4(4) where PMDT = N,N,N′,N″,N″-pentamethyldiethylenetriamine, OAc = Acetate ion were synthesized and characterized by means of spectroscopic, magnetic and cyclic voltammetric measurements. In frozen solution e.p.r. spectra, an interesting relation g|| > g⊥ has been observed which is a typical of the axially symmetric d9 CuII (SCu = 1/2) having an unpaired electron in a dx2−y2dx2−y2 orbital. Single crystal X-ray analysis of (1) has revealed the presence of distorted square planar geometry. The influence of the counter ion on the complexes has been examined by performing some biological experiments like superoxide dismutase and anti-microbial activity.