单核、对称双核钌配合物在铂电极上的电化学行为  

Electrochemical Behavior of Mononuclear and Symmetrical Binuclear Ruthenium (Ⅱ) Complexes on a Platinum Electrode

作　　者：李红[1] 蒋雄[2] 巢晖[1] 叶保辉[1] 计亮年[1] 

机构地区：[1]中山大学化学与化学工程学院,广州510275 [2]华南师范大学化学系,广州510631

出　　处：《化学学报》2000年第7期825-830,共6页Acta Chimica Sinica

基　　金：国家自然科学基金(29871036);广东省自然科学基金(970211)资助课题

摘　　要：利用循环伏安、循环交流伏安和微分电容测定等电化学方法研究了由2,2＇-联吡啶(bpy)和桥联配体1,4-二(2-咪唑并[4,5-f][1,10]邻菲咯啉)苯(DIPB)配位而成的单核钌配合物[Ru1:Ru(bpy)_2(DIPB)(ClO_4)_2]和对称双核钌配合物[Ru2:(bpy)_2Ru(DIPB)Ru(bpy)_2(ClO_4)_4]在铂电极上的电化学行为.研究结果表明,在0.1mol/L高氯酸四丁基铵(TBAP)的乙腈溶液中,这两种配合物的中心钌离子在铂电极上均呈现一对氧化还原峰,而配体2,2＇-联吡啶则呈现两对氧化还原峰.单核Ru1和双核Ru2所对应的各组氧化还原峰分别符合可逆的单电子和二电子传递反应过程的特征,所对应的条件电位(Fromal Potential)Ru2较Ru1有轻微正移.Ru1和Ru2所对应的配位阳离子的扩散系数分别为9.93×10^(-6)cm^2/s和3.50×10^(-6)cm^2/s.在循环交流法和微分电容法确定的时间量程内,两中心钌离子在桥联配体间的电子传递过程较它与电极间的慢.The electrochemical behaviors of mononuclear and symmetrical binuclear ruthenium (Ⅱ) complexes [Ru1: Ru(bpy)2(DIPB)(ClO4)2 and Ru2:(bpy)2Ru(DIPB)Ru (bpy)2(ClO4)4] containing dinuclear ligand 2,2' - bipyridine(bpy) and bridging ligand 1,4 - di(2 - imidazo[4,5 - f] [1, 10]phenanthroine) benzene (DIPB) on a platinum electrode have been investigated using cyclic voltammetry, cyclic ac voltammetry and differential capacitance techniques, etc. In acetonitrile solutions containing 0. 1mol/L TBAP, the Ru1 and Ru2 complexes have shown the following electrochemical characteristics respectively: a single 1e and 2e reversible oxidation - reduction waves for their central ruthenium ions, two 1e and 2e reversible oxidation - reduction waves for their bipyridine ligands, slightly positive formal potentials of Ru2 compared with that of Ru1, and a much larger apparent diffusion coefficient of the Ru1 complex cation than that of Ru2, i. e., 9 .93×10-6cm2/s and 3.50×10-6cm2/s. It appears that the electron transfer process between the two central ruthenium ions through the bridging ligand is slower than that between the complex and electrode within the time period defined by cyclic ac voltammetry and differential capacitance techniques.

关 键 词：电化学行为 对称双核钌(Ⅱ)配合物 铂电极 吸附 

分 类 号：O646[理学—物理化学]