Place Christophe, Zimmermann Jean-Luc, Mulliez Etienne, Guillot Geneviève, Bois Claudette, Chottard Jean-Claude
Laboratoire de Chimie et Biochimie Pharmacologiques et Toxicologiques (CNRS URA 400), Université René Descartes, 45 rue des Saints Pères, 75270 Paris Cedex 06, France, Département de Biologie Cellulaire et Moléculaire, Section de Bioénergétique, CEA/Saclay, 91191 Gif-sur-Yvette, France, and Laboratoire de Chimie des Métaux de Transition, Université Pierre et Marie Curie, 75252 Paris Cedex 05, France.
Inorg Chem. 1998 Aug 10;37(16):4030-4039. doi: 10.1021/ic9715660.
Copper(II) complexes of the following polyimidazole ligands have been synthesized: bis(imidazol-2-yl)methane (BIM), bis(imidazol-2-yl) ketone (BIK), 4-(imidazol-4-ylmethyl)-2-(imidazol-2-ylmethyl)imidazole (TRIM), bis[4-(imidazol-4-ylmethyl)imidazol-2-yl]methane (TIM), and bis[4-(imidazol-4-ylmethyl)imidazol-2-yl] ketone (TIK). Their crystal structures have been determined using X-ray diffraction. [Cu(ClO(4))(2)(BIM)(2)], 1, belongs to the triclinic space group P&onemacr; system, a = 7.161(4) Å, b = 7.986(6) Å, c = 9.865(3) Å, alpha = 76.73(5) degrees, beta = 71.18(3) degrees, gamma = 76.44(5) degrees, Z = 1, T = 291 K; R = 0.035, R(w) = 0.036 for 1668 reflections; Cu-N = 1.998(3) and 2.001(2) Å, Cu-O = 2.574(4) Å, in a tetragonal geometry. Cu(BIK)(2)(2), 2, belongs to the monoclinic space group C2/c system, a = 9.029(3) Å, b = 12.497(2)Å, c = 19.197(2) Å, beta = 94.59(2) degrees, Z = 4, T = 291 K; R = 0.056, R(w) = 0.061 for 1052 reflections; Cu-N = 1.961(7) and 1.954(7) Å, in a distorted tetrahedral geometry. [CuCl(TRIM)(CH(3)OH)]Cl, 6, belongs to the monoclinic space group P2(1)/n system, a = 14.192(5) Å, b = 13.832(5) Å, c = 7.913(3) Å, beta = 90.55(4) degrees, Z = 4, T = 291 K; R = 0.062, R(w) = 0.057 for 1377 reflections; Cu-N = 1.987(7), 2.007(7) and 2.007(6) Å, Cu-O = 2.521(7) Å, Cu-Cl = 2.298(2) Å, in a square pyramidal geometry. Cu(ClO(4))(TIM), 4, belongs to the triclinic space group P&onemacr; system, a = 9.604(4) Å, b = 11.508(6) Å, c = 12.003(8) Å, alpha = 58.79(4) degrees, beta = 94.59(2) degrees, gamma = 67.43(3) degrees, Z = 2, T = 291 K; R = 0.057, R(w) = 0.062 for 2084 reflections; Cu-N = 1.985(7), 1.964(7), 1.967(7), and 1.966(7) Å, Cu-O = 2.553(8) Å, in a distorted square pyramidal geometry. CuCl(TIK), 7, belongs to the triclinic space group P&onemacr; system, a = 7.432(3) Å, b = 12.573(3) Å, c = 12.945(2) Å, alpha = 114.94(4) degrees, beta = 92.46(2) degrees, gamma = 103.49(3) degrees, Z = 2, T = 291 K; R = 0.043, R(w) = 0.049 for 2305 reflections; Cu-N = 1.984(5), 1.989(5), 2.012(5), and 1.979(5) Å, Cu-Cl = 2.796(2) Å, in a distorted bipyramidal geometry. In methanol solution, the perchlorato complexes 1, 2, Cu(TRIM)(ClO(4))(2) (3), 4, and Cu(TIK)(ClO(4))(2) (5) exhibited redox potentials from -215 to +284 mV vs NHE together with a visible absorption from 604 to 728 nm. Electron spin-echo envelope modulation (ESEEM) spectroscopy data, particularly the nuclear quadrupole interaction (NQI) parameters e(2)qQ and eta of the remote nitrogen (N1H), were analyzed and interpreted according to the model devised by Jiang et al. (J. Am. Chem. Soc. 1990, 112, 9035) with reference to Cu(HIm)(4)(ClO(4))(2). The results are the following: (i) C2 substitution of the imidazole ring, next to the remote nitrogen (1, 2) decreases the asymmetry parameter eta to ca. 0.75 compared to 1.00 for Cu(HIm)(4)(ClO(4))(2); this effect of C2 substitution on the symmetry of the electric field gradient at N1H appears similar for both the electron-donating methylene substituents (1) and the electron-withdrawing carbonyl group (2). (ii) The electron-donating or -withdrawing properties of the substituent are reflected by the variation of the e(2)qQ parameter, increasing from 1.43 to 1.75 MHz (1) or decreasing to 1.38 MHz (2), and by the nu(+) transition shifting toward higher frequencies from 1.49 to 1.65 MHz (1, 3, 4) or to lower frequencies to 1.29 MHz (2, 5). The use of the eta and nu(+) parameters to assign the Ndelta vs Nepsilon coordination of histidine to the metal and to detect modified histidine in copper-binding proteins is discussed.
已合成了以下聚咪唑配体的铜（II）配合物：双（咪唑-2-基）甲烷（BIM）、双（咪唑-2-基）酮（BIK）、4-（咪唑-4-基甲基）-2-（咪唑-2-基甲基）咪唑（TRIM）、双[4-（咪唑-4-基甲基）咪唑-2-基]甲烷（TIM）和双[4-（咪唑-4-基甲基）咪唑-2-基]酮（TIK）。使用X射线衍射测定了它们的晶体结构。[Cu(ClO(4))(2)(BIM)(2)]，1，属于三斜晶系空间群P&onemacr;，a = 7.161(4) Å，b = 7.986(6) Å，c = 9.865(3) Å，α = 76.73(5)°，β = 71.18(3)°，γ = 76.44(5)°，Z = 1，T = 291 K；对于1668个反射，R = 0.035，R(w) = 0.036；Cu-N = 1.998(3)和2.001(2) Å，Cu-O = 2.574(4) Å，呈四方几何构型。Cu(BIK)(2)(2)，2，属于单斜晶系空间群C2/c，a = 9.029(3) Å，b = 12.497(2)Å，c = 19.197(2) Å，β = 94.59(2)°，Z = 4，T = 291 K；对于1052个反射，R = 0.056，R(w) = 0.061；Cu-N = 1.961(7)和1.954(7) Å，呈扭曲四面体几何构型。[CuCl(TRIM)(CH(3)OH)]Cl，6，属于单斜晶系空间群P2(1)/n，a = 14.192(5) Å，b = 13.832(5) Å，c = 7.913(3) Å，β = 90.55(4)°，Z = 4，T = 291 K；对于1377个反射，R = 0.062，R(w) = 0.057；Cu-N = 1.987(7)、2.007(7)和2.007(6) Å，Cu-O = 2.521(7) Å，Cu-Cl = 2.298(2) Å，呈方锥几何构型。Cu(ClO(4))(TIM)，4，属于三斜晶系空间群P&onemacr;，a = 9.604(4) Å，b = 11.508(6) Å，c = 12.003(8) Å，α = 58.79(4)°，β = 94.59(2)°，γ = 67.43(3)°；Z = 2，T = 291 K；对于2084个反射，R = 0.057，R(w) = 0.062；Cu-N = 1.985(7)、1.964(7)、1.967(7)和1.966(7) Å，Cu-O = 2.553(8) Å，呈扭曲方锥几何构型。CuCl(TIK)，7，属于三斜晶系空间群P&onemacr;，a = 7.432(3) Å，b = 12.573(3) Å，c = 12.945(2) Å，α = 114.94(4)°，β = 92.46(2)°，γ = 103.49(3)°，Z = 2，T = 291 K；对于2305个反射，R = 0.043，R(w) = 0.049；Cu-N = 1.984(5)、1.989(5)、2.012(5)和1.979(5) Å，Cu-Cl = 2.796(2) Å，呈扭曲双锥几何构型。在甲醇溶液中，高氯酸根配合物1、2、Cu(TRIM)(ClO(4))(2)（3）、4和Cu(TIK)(ClO(4))(2)（5）相对于标准氢电极（NHE）的氧化还原电位在-215至+284 mV之间，同时在604至728 nm处有可见吸收。根据Jiang等人（《美国化学会志》1990年，112卷，9035页）设计的模型，并参考Cu(HIm)(4)(ClO(4))(2)，对电子自旋回波包络调制（ESEEM）光谱数据，特别是远程氮（N1H）的核四极相互作用（NQI）参数e(2)qQ和η进行了分析和解释。结果如下：（i）咪唑环中与远程氮相邻的C2取代（1、2）使不对称参数η降至约0.75，而Cu(HIm)(4)(ClO(4))(2)的η为1.00；对于给电子的亚甲基取代基（1）和吸电子的羰基（2），C2取代对N1H处电场梯度对称性的这种影响似乎相似。（ii）取代基的给电子或吸电子性质通过e(2)qQ参数的变化反映出来，从1.43 MHz增加到1.75 MHz（1）或降至1.38 MHz（2），并且通过ν(+)跃迁向更高频率移动，从1.49 MHz移至1.65 MHz（1、3、4）或向更低频率移至1.29 MHz（2、5）。讨论了使用η和ν(+)参数来确定组氨酸与金属的Nδ对Nε配位以及检测铜结合蛋白中修饰的组氨酸。
