The title complex [Cu(en)2]•[Cu(pht)2]2 (Hpht＝5,5-diphenylhydantoin, i.e. phenytoin; en＝ethylenediamine) was synthesized solvent-thermally and characterized by elemental analysis, IR, TG-DSC and single-crystal X-ray diffraction. The crystal of the complex belongs to triclinic system with space group Pī, a＝0.8453(2) nm, b＝1.1878(3) nm, c＝1.5674(4) nm, α＝101.197(3)°, β＝97.690(3)°, γ＝103.283(3)°, V＝1.476(6) nm 3, Dc＝1.480 g/cm3, Z＝1, F(000)＝679, µ＝1.139 mm－1, final R [I＞2σ(I)]: R1＝0.0402 , wR2＝0.0962 and GOF＝1.035. The XPS and single-crystal X-ray diffraction data demonstrated that the complex was mix-charged, including two Cu(I) and one Cu(II) metal centers. The Cu(I) atom was coordinated by two nitrogen atoms from two phenytoin ligands, and the angle of N—Cu(I)—N was 177°. The Cu(II) atom adopted a distorted CuN4O2 octahedron configuration when coordinated with two en and two phenytoin ligands. The interaction between the complex and CT-DNA was studied by UV spectroscopy, fluorescence spectroscopy and viscosity measurements, which confirmed the intercalation effect of the complex into DNA double helix.

Key words: 5,5-diphenylhydantoin, copper(I/II) complex, calf thymus DNA