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Cu(II) and Ni(II)‐1,10‐phenanthroline‐ 5,6‐dione‐amino acid ternary complexes exhibiting pH‐sensitive redox properties
Author(s) -
Xu GuangJun,
Kou YingYing,
Feng Li,
Yan ShiPing,
Liao DaiZheng,
Jiang ZongHui,
Cheng Peng
Publication year - 2006
Publication title -
applied organometallic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.53
H-Index - 71
eISSN - 1099-0739
pISSN - 0268-2605
DOI - 10.1002/aoc.1064
Subject(s) - chemistry , redox , electrochemistry , phenanthroline , cyclic voltammetry , crystallography , semiquinone , pourbaix diagram , orthorhombic crystal system , crystal structure , ternary operation , saturated calomel electrode , inorganic chemistry , ligand (biochemistry) , quinone , stereochemistry , medicinal chemistry , reference electrode , electrode , biochemistry , receptor , computer science , programming language
Syntheses, and electrochemical properties of two novel complexes, [Cu(phendio)( L ‐Phe)(H 2 O)](ClO 4 ) ·H 2 O (1) and [Ni(phendio)(Gly)(H 2 O)](ClO 4 )·H 2 O (2) (where phendio = 1,10‐phenanthroline‐5,6‐dione, L ‐Phe = L ‐phenylalanine, Gly = glycine), are reported. Single‐crystal X‐ray diffraction results of (1) suggest that this complex structure belongs to the orthorhombic crystal system. The electrochemical properties of free phendio and these complexes in phosphate buffer solutions in a pH range between 2 and 9 have been investigated using cyclic voltammetry. The redox potential of these compounds is strongly dependent on the proton concentration in the range of − 0.3–0.4 V vs SCE (saturated calomel reference electrode). Phendiol reacts by the reduction of the quinone species to the semiquinone anion followed by reduction to the fully reduced dianion. At pH lower than 4 and higher than 4, reduction of phendio proceeds via 2e − /3H + and 2e − /2H + processes. For complexes (1) and (2), being modulated by the coordinated amino acid, the reduction of the phendio ligand proceeds via 2e − /2H + and 2e − /H + processes, respectively. Copyright © 2006 John Wiley & Sons, Ltd.