Walker Tia L, Mula Sam, Malasi Wilhelm, Engle James T, Ziegler Christopher J, van der Est Art, Modarelli Jody, Taschner Michael J
Department of Chemistry, Indiana University Northwest, Gary, IN 46408, USA.
Department of Chemistry, Brock University, St. Catharines, ON L2S 3A1, Canada.
Dalton Trans. 2015 Dec 14;44(46):20200-6. doi: 10.1039/c5dt03389f.
To improve understanding of copper at the active site of Type 1 copper proteins, Cu(I) and Cu(II) complexes of 1,8-dithia-4,11-diazacyclotetradecane, shown in , have been successfully isolated and structurally characterized by X-ray crystallography. In these compounds, both Cu(I) and Cu(II) are centered in the plane of the macrocycle containing two sulphur and two nitrogen heteroatoms comprising the distorted tetrahedral/square planar coordination geometry. The UV/VIS spectra, electrochemistry and EPR properties have been obtained for the Cu(II) complex 2. Three absorption bands at 295 nm, 354 nm, and 545 nm are observed in aqueous solution at a pH of 5. These bands have been assigned to the N → Cu(II) and S → Cu(II) charge transfer bands and the d-d transitions respectively. The Cu(I/II) redox midpoint potential of complex 2 in CH3CN is +403 mV versus NHE.
为了更好地理解1型铜蛋白活性位点处的铜，已成功分离出如图所示的1,8 - 二硫杂 - 4,11 - 二氮杂环十四烷的Cu(I)和Cu(II)配合物，并通过X射线晶体学对其进行了结构表征。在这些化合物中，Cu(I)和Cu(II)均位于大环平面中心，该大环包含两个硫和两个氮杂原子，构成扭曲的四面体/平面正方形配位几何结构。已获得Cu(II)配合物2的紫外/可见光谱、电化学和电子顺磁共振性质。在pH为5的水溶液中观察到295 nm、354 nm和545 nm处的三个吸收带。这些吸收带分别被归属为N→Cu(II)和S→Cu(II)电荷转移带以及d - d跃迁。配合物2在乙腈中的Cu(I/II)氧化还原中点电位相对于标准氢电极（NHE）为 +403 mV。
