Comparative studies between 4-allyl-, 4-phenyl- and 4-ethyl-1-(2-hydroxybenzoyl) thiosemicarbazides and the synthesis, characterization and DFT calculations of binary and ternary complexes derived from 4-ethyl (L1) and 2,2′-dipyridyl

The metal complexes of 4-ethyl-1-(2-hydroxybenzoyl) thiosemicarbazide (L-1) with MCl2 (M = Co2+, Cu2+ and Zn2+) and Zn(Ac)(2) in EtOH were synthesized and characterized using spectral (IR, H-1-NMR, mass, UV-Visible), magnetic moment and thermal measurements. Binary and ternary complexes with the general formulae, [Cu(L-1-H)(2)]center dot EtOH, [Co(L-1-H)(2)], [Zn-3(L-1-H)(L-1)(Ac)(5)], [Cu-2(L-2)(2)(L-1-2H)(2)(H2O)(2)]center dot 4H(2)O, [Co(L-2)(L-1-2H)]center dot 3H(2)O and [Zn-2(L-2)(OH)(L-1-3H)(H2O)center dot 1/2EtOH where L-2 is 2,2'-dipyridyl, have been suggested and characterized. The bond lengths, bond angles, chemical reactivates, energy components, binding energies and dipole moments for the isolated complexes were evaluated by DFT method from DMOL3. Also, the MEP for L-1 is illustrated. The existence of the OH group in the Zn2+ ternary complexes is confirmed by IR, mass and H-1-NMR spectra. Biological activity for the L-1 and some its complexes was tested against DNA. Comparative studies between the ligation behavior and reactivity of our previous work derived from 4-phenyl- and 4-allyl-1-(2-hydroxybenzoyl) thiosemicarbazides have been investigated. (C) 2015 Elsevier B.V. All rights reserved.