Crystal structures, cyclic voltammetry and DNA binding of two mononuclear nickel(II) complexes

• Published in: Transition metal chemistry (Weinheim) 2014-02, Vol.39 (1), p.111-118
• Main Authors: Wang, Yang, Mao, Jia-Wei, Ding, Chao, Pan, Zhi-Quan, Li, Jian-Fen, Zhou, Hong
• Format: Article
• Language: English
• Subjects: Catalysis; Chemistry; Chemistry and Materials Science; Inorganic Chemistry; Organometallic Chemistry; Physical Chemistry
• ISSN: 0340-4285; 1572-901X
• DOI: 10.1007/s11243-013-9779-4

Two unsymmetrical complexes, [NiL 1 ]ClO 4 ( 1 ) and [NiL 2 ]ClO 4 ( 2 ) have been synthesized and characterized by IR, UV, ES-MS and single crystal X-ray diffraction, where HL 1 and HL 2 are, respectively, the [1+1] condensation products of 2,6-diformyl-4-X-phenol (X = F or CH 3 ) with N 1 -(2-aminoethyl)- N 2 -(4-nitrobenzyl) ethane-1,2-diamine. The coordination geometry of the metal in both complexes can be approximately described as square planar with a mean plane deviation of 0.032 Å in complex 1 and 0.027 Å in complex 2 , respectively. The binding activities of the complexes toward calf-thymus DNA have been analyzed by spectroscopy and viscosity methods. The binding constants of 1 and 2 obtained from UV spectroscopic studies are 5.43 × 10 5 and 1.83 × 10 5  M −1 , respectively, while the linear Stern–Volmer quenching constants obtained from fluorescence spectroscopic studies are 0.83 × 10 3 and 0.71 × 10 3  M −1 , respectively. The cyclic voltammograms of the complexes show a pseudo-reversible electrochemical process.