Synthesis and pH-sensitive redox properties of 1,10-phenanthroline-5,6-dione complexes.

Kou, Ying-Ying; Xu, Guang-Jun; Gu, Wen; Tian, Jin-Lei; Yan, Shi-Ping

Synthesis and pH-sensitive electrochemical properties of three complexes, [Cu(PD)3] · (ClO4)2 · 2.25CH3CN · 6H2O (1), [Cu(PD)(DMSO)Cl2] · DMSO · H2O (2) and [Co(PD)3] · (ClO4)2 · CH3CN · 2H2O (3) (PD=1,10-phenanthroline-5,6-dione), are reported. Single-crystal X-ray diffraction of the complexes suggest that the structure of 1 is orthorhombic, 2 triclinic and 3 orthorhombic. The electrochemical properties of free PD and the three complexes in phosphate buffer solutions in a pH range between 2 and 9 have been investigated using cyclic voltammetry. The redox potentials of these compounds are strongly dependent on the proton concentration in the range -0.3 V ∼ 0.4 V versus SCE (saturated calomel reference electrode). The reduction behavior of PD can be described from quinone species to semiquinone anion then to the fully reduced dianion. At pH 4, the reduction of PD proceeds via 2e-/2H . For all complexes, the N-N chelate PD ligand is electrochemically active and underwent step reduction via 2e-/2H .

OXIDATION-reduction reaction; COPPER; COBALT; VOLTAMMETRY; METALS

Journal of Coordination Chemistry, 2008, Vol 61, Issue 19, p3147

0095-8972

Academic Journal

10.1080/00958970802010575