Synthesis and characterization of a mononuclear Fe(II) compound [Fe(L)](ClO4)2 (1) [L = N-(1-pyridin-2-yl-phenylidene)-N'-[2-({2-[(1-pyridin-2-ylphenylidene)amino]ethyl}amino)ethyl] ethane-1,2-diamine] (1) is reported. 1 crystallizes in P-1 space group with a = 11.9241(3) Å, b = 12.1994(3) Å and c = 13.0622(4) Å. The binding property of the complex with DNA has been investigated using absorption and emission studies, thermal melting, viscosity experiments and circular dichroism studies. The binding constant ($K_b$) and the linear Stern-Volmer quenching constant ($K_{\text{sv}}$) of the complex have been determined as $3.5 \times 10^3$M^-1 and $2.73 \times 10^4$M^-1, respectively. Spectroscopic and hydrodynamic investigations revealed intercalative mode of binding of 1 with DNA. 1 is also found to induce oxidative cleavage of the supercoiled pUC 18 DNA to its nicked circular form in a concentration dependent manner.

Synthesis and X-ray structural characterization of three complexes of type cis-[M(dafone)₂(NCS)₂] (M = Co(II), 1; Ni(II), 2; Zn(II), 3; dafone = 4,5-diazafluoren-9-one) and a polymer cis-[Cd(dafone)(NCS)₂]$_n$ (4) have been reported. Each of the four complexes is crystallized in orthorhombic crystal system. Structural study reveals that each metal(II) centre in the four complexes adopts distorted octahedral geometry with MN₆ chromophore in 1-3 and MN₄S₂ chromophore in 4. The room temperature steady-state fluorescent intensity of dafone in dimethyl formamide at 402 nm is found to be quenched in these reported dafone complexes (1-4).

Synthesis and characterization of a mononuclear Ni(II) compound [Ni(L)(H₂O)₂](NO₃)₂ [L = N,N'-bis((pyridine-2-yl)phenylidene)-1,3-diaminopropan-2-ol] (1) is reported. 1 crystallizes in triclinic P-1 space group with a = 8.1911(2) Å, b = 11.6624(3) Å, c = 16.5356(4) Å and𝛼 = 108.8120(10)° , 𝛽 = 91.2010(10)° , 𝛾 = 91.1500(10)° . The binding property of the complex with DNA has been investigated using absorption and emission studies, and viscosity experiment. The binding constant (K_b) and the linear Stern-Volmer quenching constant (K_sv) of the complex have been determined as 9.23 × 10 4 M⁻¹ and 2.0 × 10 4 M⁻¹, respectively. Spectroscopic and hydrodynamic investigations revealed groove or electrostatic nature of binding of 1 with DNA. 1 is also found to induce oxidative cleavage of the supercoiled pUC 18 DNA to its nicked circular form in a concentration dependent manner.