Pyridine-2-carboxaldehyde-semicarbazone (PCS) complex [(H2PCS).Cl](+)[Fe(II)(PCS)Cl-3](-).[Fe(III)(PCS)Cl-3] center dot (HPCS) center dot (Cl) (1) and 2,3-diacetylhydrazoneoxime (DAHO) complex [Cu-2(mu-Cl)(2)(DAHO)(2)Cl-2] (2) have been synthesized and characterized by different spectroscopic techniques. Structures were confirmed by single crystal X-ray crystallographic technique. Complex 1 crystallizes as Fe(II)/Fe(III) coordination complex in triclinic crystal system. EPR signals of 1 at g = 4.2 and g = 1.8 show transitions within m(S) = +/- 3/2 and m(S) = +/- 1/2 Kramers' doublets of high spin (S = 5/2) distorted octahedral Fe(III) complex. Complex 2 crystallizes in triclinic system as square pyramidal chloro-bridged dinuclear copper(II) complex. The complexes were found to be groove binding to calf-thymus DNA.

(E)-1-((pyridin-2-yl)methylidene)semicarbazide (PMSC) complexes of [Mn(PMSC)2 ]Cl2 (1), [Co(PMSC)2]Cl2 (2), [Ni(PMSC)2]Cl2.5H2O (3), and [Cu(PMSC)(H2O)]Cl2 (4) have been synthesized and characterized by different spectroscopic techniques, EPR, magnetic susceptibility and thermal stability measurements. Complex 3 crystallizes as octahedral coordination complex in monoclinic crystal system. Complexes 1 and 2 have been found to have octahedral geometries and 4 to have square planar geometry. The complexes were found to be groove binding to calf-thymus DNA.

Two Bis-(benzoylacetonato)cobalt(II) and nickel (II) complexes has been synthesized and their characterization has been done on the basis of CHN analyses, IR, UV-Vis, X-ray powder pattern techniques. The cobalt(II) complexes has triclinic crystal system with unit cell dimensions, a = 6.499; b = 5.300; c = 11.327 and α = 86.754; β = 111.279;γ = 98.620, whereas the nickel (II) complex has monoclinic system with a = 12.8142; b = 5.1697; c = 9.2825 and β = 141.849. The thermal decomposition steps of the complexes have been studied by thermogravimetric and differential thermal analyses. Thermodynamic parameters like activation energy (Ea*), ∆H, ∆S and ∆G for each decomposition of the complexes in the solid state were evaluated by following some standard methods and useful conclusions were drawn. The ∆G and ∆S of the systems were found to be negative, indicating the reactions were thermodynamically allowed.

A novel copper (II) complex, [Cu(HL)2] (where, HL=3-(4-(sulphonamine)phenylimino)-1-phenylbut-1-en-1-ol) has been synthesized and characterized by IR, UV–vis, magnetic susceptibility measurement and single crystal X-ray crystallographic studies. The crystal data confirm the square planarity of the prepared complex having an orthorhombic space group Pca2 (1). Molecular packing of the complex is stabilized by N―H…O hydrogen bonding and weak N―H…O, C―H…Cg π-ring intermolecular interactions, hence forming a two dimensional supramolecular network structure. CT-DNA binding studies have been carried out by monitoring electronic absorption titrations, luminescence titrations, a DNA melting, cyclic voltametry and viscosity measurement studies. An intercalative mode of DNA binding is suggested for the prepared copper (II) complex.

Four new Cu(II) Complexes viz. [Cu(II)(1-amidino-O-methylurea)2]SO4·2H2O (1), [Cu(II)(1-amidino-O-ethylurea)2](SO4)2·2H2O (2), [Cu(II)(1-amidino-O-n-propylurea)2] SO4·2H2O (3), [Cu(II)(1-amidino-O-n-butylurea)2]2(SO4)2·2H2O (4) have been synthesized and characterized. EPR spectrum of complex 4 at RT consisted of fine-structure transitions (ΔMs=±1) with zero-field splitting (ZFS) of 0.0485cm−1 and a half-field signal (ΔMs=±2) at ca. 1600G, revealed formation of binuclear complex (S=1). Whereas EPR spectrum of complex 2 in DMSO showed a mixture of mononuclear and binuclear complex in the ratio 0.75:1.0 with ZFS of 0.0385cm−1. From the temperature dependence of the EPR signal intensity, the isotropic exchange-interaction constant J was evaluated.