Comparative spectroscopic and DFT calculations of binary and ternary complexes derived from 4-allyl-1-(2-hydroxybenzoyl) thiosemicarbazide (L¹) and 2,2'-dipyridyl.

Five metal complexes derived the reactions of 4-allyl-1-(2-hydroxybenzoyl) thiosemicarbazide (L(1)) with MX2 (M=Co(2+), Cu(2+) and Zn(2+) ions; X=Cl(-) in case of Co(2+) and Cu(2+) ions and Cl(-) and Ac(-) in case of Zn(2+) ion) in EtOH were synthesized and characterized. The results suggested that the binary and ternary complexes have the general formulae, [Cu(L(1)-2H)(EtOH)], [Co(L(1)-2H)(H₂O)₂]⋅H₂O and [Zn(L(1)-2H) (H₂O)1/2]⋅½EtOH, [Cu₂(dipy)(L(1)-2H)(OH)₂(H₂O)], [Co(dipy)(L(1)-2H)]⋅4H₂O and [Zn(dipy)(L(1)-2H)]. The binary and ternary complexes were characterized by elemental analyses, molar conductivities, spectral (IR, UV-vis; (1)H NMR, mass), thermal (TGA, DTG) and magnetic moments measurements. The mode of chelation is suggested using spectral data. The existence of OH group in the ternary complexes is confirmed from the results of IR, mass and (1)H NMR spectra. All the geometries of the ligands and the complexes are confirmed using DFT method from DMOL(3). The biological activity for the L(1) and two metal complexes were tested against DNA.