Syntheses and Reactivity of Diiorn-, Dicobalt-, and Dicopper-Dioxygen Complexes

二铁-二氧和二铜-二氧配合物在生物和催化过程中对O_2的可逆结合和活化起着重要作用。我们开发了多种双铁（II）和双铜(I)配合物作为氧转运蛋白（如Hemerythrin （Fe_2）和hemocyanin (Cu_2)）和单加氧酶（如甲烷单加氧酶（Fe_2或Cu_n））的功能模型。二铁配合物：只有少数的结构和光谱表征的二铁-二氧配合物已被报道。为了合成二铁-二氧配合物，重要的是控制适合两个铁离子结合O_2的配体环境，稳定多过氧物质的不可逆氧化。为此，开发了一系列具有空间位阻吡啶基和咪唑基的二核配体，这些配体具有n_60给体和酚酸酯或醇盐桥接基。它们形成五坐标双核[Fe_2 (L) (RCO_2)]^<2+>，并与O_2反应形成多羧酸桥。研究发现，这些配合物对不可逆氧化的热稳定性和对氧的亲和力高度依赖于二核配体和桥接羧酸盐的立体化学和电子给体能力。最后，我们成功地制备了顺式-1,2-过氧二铁配合物，并对其结构进行了表征，这是第一个在室温下可逆结合O_2的二铁-二氧配合物的晶体学表征。二铜配合物：合成了一系列具有三足四齿配体（(R_1R_2NCH_2CH_2)_3N: L）的铜(I)配合物（[Cu (L)]^+）。研究了这些配合物与O_2的反应性。它们在低温下形成反式-1,2-过氧化物。研究发现，二氧配合物的立体化学和热稳定性高度依赖于取代基的空间体积(R)。我们成功地表征了一种反式-1,2-过氧化合物([Cu (（BnHNCH_2CH_2)_3N)]_2 (O_2)）的结构特征，其中苯基（Bn）在Cu^<2+>-O_2^<2->-Cu^<2+>部分周围形成一个空腔，从而稳定了过氧化合物。少

Diiron-dioxygen and dicopper-dioxygen complexes play an important role in the reversible binding and activation of O_2 in biological and catalytic processes. We developed various diiron (II) and dicopper (I) complexes as functional models for O_2 transport proteins such as Hemerythrin (Fe_2) and hemocyanin (Cu_2) and mono-oxygenase such as methane monooxygenases (Fe_2 or Cu_n).Diiron Complexes : Only a few structurally and spectroscopically characterized diiron-dioxygen complexes have been reported. In order to synthesize the diiron-dioxygen complexes, it is important to control the ligand environment which is suitable for O_2 binding by two iron ions and stabilizes the mu-peroxo species toward irreversible oxidation. For this purpose, a series of dinucleating ligands with sterically hindered pyridyl and imidazolyl groups has been developed, which has an N_6O donor set with a phenolate or alkoxide bridging group. They form five-coordinate dinuclear [Fe_2 (L) (RCO_2)]^<2+> with an exoge … More nous carboxylate bridge, which react with O_2 to form mu-peroxo species. It was found that thermal stability toward irreversible oxidation and dioxygen affinity of those complexes are highly dependent on the stereochemistry and the electron donor ability of dinucleating ligands and bridging carboxylate. Finally we have succeeded in preparation and structural characterization of a cis-mu-1,2-peroxo diiron complex which is the first example of a crystallographically characterized diiron-dioxygen complex that binds O_2 reversibly at ambient temperature.Dicopper Complexes : A series of copper (I) complexes ([Cu (L)]^+) having tripodal tetradentate ligands ((R_1R_2NCH_2CH_2)_3N : L) was synthesized. Reactivity of those complexes with O_2 was investigated. They form trans-mu-1,2-peroxo species at low temperature. It was found that stereochemistry and thermal stability of dioxygen complexes are highly dependent on the steric bulkiness of substituents (R). We have succeeded in structural characterization of a trans-mu-1,2-peroxo species ([Cu ((BnHNCH_2CH_2)_3N)]_2 (O_2)), where benzyl (Bn) groups form a cavity around Cu^<2+>-O_2^<2->-Cu^<2+> moiety, which stabilizes peroxo species. Less