Interactions of atrazine with transition metal ions in aqueous media: experimental and computational approach

Transition metal ions have their own significances and utility. Externally applied pesticides may alter the bioavailability of these metal ions to plants through the coordinating ability of these pesticides with metal ions. In current study a series of metal complexes containing atrazine (Atr) group(s) attached to metal(II) (M) frame, with the formula; [M(Atr)_n.xH₂O.yCl] (where M = Mn, Fe, Co, Ni, Cu or Zn; n = 1 or 2; x = 1-4; y = 1-2), have been synthesized for the first time to check the interactions of atrazine with transition metal ions. More importantly, all the complexes were synthesized at neutral pH in aqueous medium. The major differences among the FTIR spectra were observed between 3,700-2,800 and 1,800-1,350 cm^-1. On the basis of FTIR, CHN and computational study, it was observed that Mn, Ni and Cu formed complexes in 1:2 and Fe, Co and Zn in 1:1. The obtained results were supported by 3D molecular modeling using GAMESS computations as a package of ChemBio3D Ultra14 program. The FTIR spectral analysis and 3D molecular modeling suggests that the Atr can show coordination through the nitrogen (in between two side chains) of ring as well as nitrogen (non steric amine) of side chain with different metal ions.