Design and creation of reaction active multinuclear metal complex

(1)合成了基于‘末端-OFF’型二核室配体的类磷酸三酯酶水解物functionBis(μ-carboxylato)-μ-phenolatocomplexes，[M_2(L)(ACO)_2]^+(M=Mn，Co，Ni，Zn)，作为催化三(对硝基苯基)磷酸(→)双(对硝基苯基)磷酸(BNP^-)水解的磷酸三酯酶模型化合物。通过UV-Vis和ESI质谱图对水解物进行了跟踪。水解能力取决于双核的金属配位，由大到小的顺序为：MnMn~ZnZn&Gt；CoCo&Gt；&Gt；NiNi。结合到金属中心的水分子的亲核性顺序很好地解释了这种趋势。由于海洋中锌的天然丰度大于锰的天然丰度，实际的磷酸三酯酶活性中心不是锰锰而是锌锌双核。(2)用双核配合物[M_2(L)(ACO)_2]^+(M=Mn，Co，Ni，Zn)研究了双(对-硝基苯基)磷酸(BNP^-)的磷酸二酯酶活性。[M_2(L)(ACO)(BNP)]^+是由[M_2(L)(ACO)_2]^++BNP^-=[M_2(L)(ACO)(BNP)]^++ACO^-生成，其水解力顺序为：MnMnCoCo&gt；；NiNi&gt；&Gt；锌。锌锌化合物[Zn_2(L)(ACO)_2]^+的水解性很低，这是因为它与BNP-形成了刚性的μ-乙酰-μ-BNP核结构，不利于在锌核上携带水分子。在自然界中，由于海洋中钴的天然丰度远低于锰的丰度，因此磷酸二酯酶的活性中心不是CoCo，而是MnMn核心。此外，还成功地制备了第一个以FeZn为核心结构的紫色酸性磷酸酶功能模型。

(1)Phosphotriesterase-like hydrolytic functionBis(μ-carboxylato)-μ-phenolatocomplexes, [M_2(L)(AcO)_2]^+(M=Mn,Co,Ni,Zn), based on ‘end-off' type dinucleating compartment ligand have been prepared as phosphotriesterase-model compounds which catalyze the hydrolysis of tris(p-nitrophenyl)phosphate (TNP)→bis(p-nitrophenyl)phosphate (BNP^-). The hydrolysis was traced by means of UV-vis and ESI mass spectra. The ability of hydrolysis depends on the metal combination of dinuclear core and decreased in the order, MnMn〜ZnZn>CoCo>>NiNi. This tendency is well explained by the order of nucleophilicity of water molecules binding to the metal centers. Actual phosphotriesterase has not MnMn but ZnZn dinuclear core as active sites, because natural abundance of Zn in the sea is more than that of Mn.(2)Phosphodiesterase-like hydrolytic functionHydrolysis of bis(p-nitrophenyl) phosphate (BNP^-) has been studied by using of dinuclear complexes, [M_2(L)(AcO)_2]^+ (M=Mn,Co,Ni,Zn). It was revealed that the hydrolysis progresses via [M_2(L)(AcO)(BNP)]^+ which was generated from an equilibrium [M_2(L)(AcO)_2]^++BNP^-= [M_2(L)(AcO)(BNP)]^++AcO^- and the ability of hydrolysis decreased in the order, MnMn〜CoCo>>NiNi>>ZnZn. The hydrolysis ability of ZnZn compound, [Zn_2(L)(AcO)_2]^+, is very low, because it forms ‘rigid' μ-acetato-μ-BNP core structure with BNP-, which is inconvenient to take water molecules on ZnZn core. In natural, phosphodiesterase has not CoCo but MnMn core as active sites, because natural abundance of Co in the sea is much less than that of Mn. Furthermore, the first function-model of purple acid phophatase which has FeZn core structure has been prepared successfully.