Two vanadium complexes with o-vanillin derivatives, [VO2(C10H11NO3)](HOCH2CH2NH3) (1) and VO(C8H8NO3)2 (2), were synthesized and characterized by FT-IR and single crystal X-ray diffraction analysis. The interaction of the two complexes with calf thymus-DNA (Ct-DNA) has been investigated by UV-Vis absorption spectroscopy, fluorescence spectroscopy, cyclic voltammetry and viscosity measurements. The results indicated that the complex 1 interacted with Ct-DNA in a non-intercalative mode, while complex 2 might be bonded to Ct-DNA through an intercalative mode.

Key words: vanadium, o-vanillin, complex, intercalation interaction, calf thymus DNA