Casella Luigi, Carugo Oliviero, Gullotti Michele, Doldi Sergio, Frassoni Massimiliano
Dipartimento di Chimica Inorganica, Metallorganica e Analitica, Università di Milano, Centro CNR, Via Venezian 21, 20133 Milano, Italy.
Inorg Chem. 1996 Feb 28;35(5):1101-1113. doi: 10.1021/ic950392o.
The copper(I) and copper(II) complexes with the nitrogen donor ligands bis[(1-methylbenzimidazol-2-yl)methyl]amine (1-BB), bis[2-(1-methylbenzimidazol-2-yl)ethyl]amine (2-BB), N-acetyl-2-BB (AcBB), and tris[2-(1-methylbenzimidazol-2-yl)ethyl]nitromethane (TB) have been studied as models for copper nitrite reductase. The copper(II) complexes form adducts with nitrite and azide that have been isolated and characterized. The Cu(II)-(1-BB) and Cu(II)-AcBB complexes are basically four-coordinated with weak axial interaction by solvent or counterion molecules, whereas the Cu(II)-(2-BB) and Cu(II)-TB complexes prefer to assume five-coordinate structures. A series of solid state structures of Cu(II)-(1-BB) and -(2-BB) complexes have been determined. Cu(1-BB)(DMSO-O)(2)(2): triclinic, P&onemacr; (No. 2), a = 9.400(1) Å, b = 10.494(2) Å, c = 16.760(2) Å, alpha = 96.67(1) degrees, beta = 97.10(1) degrees, gamma = 108.45(1) degrees, V = 1534.8(5) Å(3), Z = 2, number of unique data [I >/= 3sigma(I)] = 4438, number of refined parameters = 388, R = 0.058. Cu(1-BB)(DMSO-O)(2)(2): triclinic, P&onemacr; (No. 2), a = 9.304(5) Å, b = 10.428(4) Å, c = 16.834(8) Å, alpha = 96.85(3) degrees, beta = 97.25(3) degrees, gamma = 108.21(2) degrees, V = 1517(1) Å(3), Z = 2, number of unique data [I >/= 2sigma(I)] = 3388, number of refined parameters = 397, R = 0.075. Cu(1-BB)(DMSO-O)(NO(2)): triclinic, P&onemacr; (No. 2), a = 7.533(2) Å, b = 8.936(1) Å, c = 19.168(2) Å, alpha = 97.66(1) degrees, beta = 98.62(1) degrees, gamma = 101.06(1) degrees, V = 1234.4(7) Å(3), Z = 2, number of unique data [I >/= 2sigma(I)] = 3426, number of refined parameters = 325, R = 0.081. Cu(2-BB)(MeOH)(ClO(4)): triclinic, P&onemacr; (No. 2), a = 8.493(3) Å, b = 10.846(7) Å, c = 14.484(5) Å, alpha = 93.71(4) degrees, beta = 103.13(3) degrees, gamma = 100.61(4) degrees, V = 1270(1) Å(3), Z = 2, number of unique data [I>/= 2sigma(I)] = 2612, number of refined parameters = 352, R = 0.073. Cu(2-BB)(N(3)): monoclinic, P2(1)/n (No. 14), a = 12.024(3) Å, b = 12.588(5) Å, c = 15.408(2) Å, beta = 101,90(2) degrees, V = 2282(1) Å(3), Z = 4, number of unique data [I >/= 2sigma(I)] = 2620, number of refined parameters = 311, R = 0.075. Cu(2-BB)(NO(2))(MeCN): triclinic, P&onemacr; (No. 2), a = 7.402(2) Å, b = 12.500(1) Å, c = 14.660(2) Å, alpha = 68.14(1) degrees, beta = 88.02(2) degrees, gamma = 78.61(1) degrees, V = 1233.0(4) Å(3), Z = 2, number of unique data [I>/= 2sigma(I)] = 2088, number of refined parameters = 319, R = 0.070. In all the complexes the 1-BB or 2-BB ligands coordinate the Cu(II) cations through their three donor atoms. The complexes with 2-BB appear to be more flexible than those with 1-BB. The nitrito ligand is bidentate in Cu(2-BB)(NO(2))(MeCN) and essentially monodentate in Cu(1-BB)(DMSO-O)(NO(2)). The copper(I) complexes exhibit nitrite reductase activity and react rapidly with NO(2)(-) in the presence of stoichiometric amounts of acid to give NO and the corresponding copper(II) complexes. Under the same conditions the reactions between the copper(I) complexes and NO(+) yield the same amount of NO, indicating that protonation and dehydration of bound nitrite are faster than its reduction. The NO evolved from the solution was detected and quantitated as the [Fe(EDTA)(NO)] complex. The order of reactivity of the Cu(I) complexes in the nitrite reduction process is Cu(2-BB) > Cu(1-BB) > Cu(TB) > Cu(AcBB).
已对与含氮供体配体双[(1 - 甲基苯并咪唑 - 2 - 基)甲基]胺(1 - BB)、双[2 - (1 - 甲基苯并咪唑 - 2 - 基)乙基]胺(2 - BB)、N - 乙酰 - 2 - BB(AcBB)以及三[2 - (1 - 甲基苯并咪唑 - 2 - 基)乙基]硝基甲烷(TB)形成的铜(I)和铜(II)配合物作为亚硝酸铜还原酶的模型进行了研究。铜(II)配合物与亚硝酸盐和叠氮化物形成了加合物，这些加合物已被分离和表征。Cu(II)-(1 - BB)和Cu(II)-AcBB配合物基本上是四配位的，通过溶剂或抗衡离子分子存在弱轴向相互作用，而Cu(II)-(2 - BB)和Cu(II)-TB配合物更倾向于呈现五配位结构。已测定了一系列Cu(II)-(1 - BB)和-(2 - BB)配合物的固态结构。Cu(1 - BB)(DMSO - O)(2)(2)：三斜晶系，P&onemacr; (编号2)，a = 9.400(1) Å，b = 10.494(2) Å，c = 16.760(2) Å，α = 96.67(1)°，β = 97.10(1)°，γ = 108.45(1)°，V = 1534.8(5) Å(3)，Z = 2，独特数据数量[I >/= 3σ(I)] = 4438，精修参数数量 = 388，R = 0.058。Cu(1 - BB)(DMSO - O)(2)(2)：三斜晶系，P&onemacr; (编号2)，a = 9.304(5) Å，b = 10.428(4) Å，c = 16.834(8) Å，α = 96.85(3)°，β = 97.25(3)°，γ = 108.21(2)°，V = 1517(1) Å(3)，Z = 2，独特数据数量[I >/= 2σ(I)] = 3388，精修参数数量 = 397，R = 0.075。Cu(1 - BB)(DMSO - O)(NO(2))：三斜晶系，P&onemacr; (编号2)，a = 7.533(2) Å，b = 8.936(1) Å，c = 19.168(2) Å，α = 97.66(1)°，β = 98.62(1)°，γ = 101.06(1)°，V = 1234.4(7) Å(3)，Z = 2，独特数据数量[I >/= 2σ(I)] = 3426，精修参数数量 = 325，R = 0.081。Cu(2 - BB)(MeOH)(ClO(4))：三斜晶系，P&onemacr; (编号2)，a = 8.493(3) Å，b = 10.846(7) Å，c = 14.484(5) Å，α = 93.71(4)°，β = 103.13(3)°，γ = 100.61(4)°，V = 1270(1) Å(3)，Z = 2，独特数据数量[I>/= 2σ(I)] = 2612，精修参数数量 = 352，R = 0.073。Cu(2 - BB)(N(3))：单斜晶系，P2(1)/n (编号14)，a = 12.024(3) Å，b = 12.588(5) Å，c = 15.408(2) Å，β = 101,90(2)°，V = 2282(1) Å(3)，Z = 4，独特数据数量[I >/= 2σ(I)] = 2620，精修参数数量 = 311，R = 0.075。Cu(2 - BB)(NO(2))(MeCN)：三斜晶系，P&onemacr; (编号2)，a = 7.402(2) Å，b = 12.500(1) Å，c = 14.660(2) Å，α = 68.14(1)°，β = 88.02(2)°，γ = 78.61(1)°，V = 1233.0(4) Å(3)，Z = 2，独特数据数量[I>/= 2σ(I)] = 2088，精修参数数量 = 319，R = 0.070。在所有配合物中，1 - BB或2 - BB配体通过其三个供体原子与Cu(II)阳离子配位。含2 - BB的配合物似乎比含1 - BB的配合物更具柔性。在Cu(2 - BB)(NO(2))(MeCN)中亚硝酸根配体是双齿的，而在Cu(1 - BB)(DMSO - O)(NO(2))中基本上是单齿的。铜(I)配合物表现出亚硝酸还原酶活性，在化学计量的酸存在下与NO(2)(-)迅速反应生成NO和相应的铜(II)配合物。在相同条件下，铜(I)配合物与NO(+)之间的反应产生相同量的NO，表明结合的亚硝酸盐的质子化和脱水比其还原更快。从溶液中逸出的NO被检测并定量为[Fe(EDTA)(NO)]配合物。铜(I)配合物在亚硝酸还原过程中的反应活性顺序为Cu(2 - BB) > Cu(1 - BB) > Cu(TB) > Cu(AcBB)。
