Synthesis, crystal structure, magnetic property, and nuclease activity of a binuclear iron(III) complex

A μ-oxo-di-μ-carboxylato-bridged iron(III) complex containing two tridentate nitrogen ligands, {[Fe2(bpma)(bpea)(μ-CH3COO)2 μ-O)] · (ClO4)2 · 0.5CH3OH} (1) (bpma = N, N-bis(2-pyridylmethyl)methyl-amine, bpea = N,N-bis(2-pyridylmethyl)ethylamine), has been synthesized and determined by X-ray diffraction. Complex 1 crystallizes in the monoclinic space group P21/c with a = 10.9434(12) A, b = 23.118(3) A, c = 15.8721(18) A, β = 92.736(2)° and Z = 4. In 1, each Fe(III) has a distorted octahedral geometry with a N3O3 donor set. The Fe(III) atoms are bridged by two carboxyl groups and one μ-oxo oxygen with Fe1–Fe2 separation of 3.064 A. Susceptibility data of 1 indicate strong intramolecular antiferromagnetic coupling of the high-spin Fe(III) atoms with J = −121.0 cm−1 and g = 2.04. The interaction with calf thymus DNA was investigated by UV absorption and fluorescent spectroscopy. Results show that the complex binds to ct-DNA with a moderate intercalative mode. The interaction between 1 and pBR322 DNA has also ...