Synthesis of metal complexes to clarify mechanism of O_2-activation by non-heme metalloproteins

合成了不同的六吡啶二核配体及其双铜配合物，得到了模拟Ⅲ型铜蛋白可逆的O_2结合和O_2活化的功能模型。根据铜络合物的反应和结构，μ-η^2：η^2-过氧二铜络合物作为III型蛋白质的活性物种，其反应受多种因素的影响，如铜的配位几何构型、两个铜离子的取向、铜-铜距离以及氮供体配体的电子效应。μ-η^2：η^2-过氧二铜配合物[Fe_2(O_2)(O)(OAc)(L)](CF_3SO_3)(2)(L：1)(L：1)[Fe_2(O_2)(O)(OAc)(L)](CF_3SO_3)(2){L：1，在乙腈存在下，[Fe_2(O)(OAc)_2(L)](CF3SO_3)_2(1b)与H_2O_2反应得到2-双[2-(双(2-吡啶)甲基)-6-吡啶]乙烷}，化合物2经元素分析、FAB-MS、电子吸收、共振拉曼和穆斯堡尔谱表征。在300K(半衰期τ_&lt；1/2&gt；=7.7h)下，2在MeCN中的自发分解符合良好的一级动力学，k=2.5×10~(-5)&gt；S^~(-1)。当RCOCl(R=m-ClC_6H_4、CH_3和CCl_3)在DMF(或DMA)存在下加成时，2被活化为相应的醇和酮的单氧环己烯和环己烷。

Various hexapyridine dinucleating ligands and their dicopper complexes have been synthesized to obtain functional models to mimic the reversible O_2-binding and O_2-activation of type III copper proteins. On the basis of reactions and structures of the copper complexes, it is shown that the reaction of μ-η^2 : η^2-peroxodicopper complex as an active species of the type III proteins is directed by various factors, such as the Cu coordination geometry, the orientation of two Cu ions, the Cu-Cu distance, and the electronic effect of the nitrogen donor ligands. Furthermore, it is suggested that the Cu-Cu distance and the distortion of the Cu coordination geometry may be important in controlling the reversible O_2-binding of the μ-η^2 : η^2-peroxodicopper complex.A thermally stable (μ-1, 2-peroxo) diiron (III) complex [Fe_2 (O_2)(O)(OAc)(L)](CF_3SO_3)(2){L : 1, 2-bis [2-(bis (2-pyridyl) methyl)-6-pyridyl]ethane} were isolated from the reaction of [Fe_2 (O)(OAc)_2 (L)](CF_3SO_3)_2 (1b) with H_2O_2 in MeCN in the presence of Et_3N.Compound 2 was characterized by elemental analysis, FAB MS, elctronic absorption, resonance Raman, and Mossbauer spectra. The spontaneous decomposition of 2 in MeCN monitored at 605 nm obeys good first-order kinetics with k=2.5x10^<-5> s^<-1> at 300 K (the half-life time τ_<1/2>=7.7 h), demonstrating that 2 is thermally stable. Upon addition of RCOCl (R=m-ClC_6H_4, CH_3, and CCl_3) in the presence of DMF (or DMA), 2 is activated to monooxygenate cyclohexene and cyclohexane to the corresponding alcohols and ketones.