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

在生物和催化过程中，二铁氧和二铜氧络合物在氧的可逆结合和活化中起着重要的作用。我们开发了不同的二铁(II)和二铜(I)络合物，作为氧转运蛋白(如异氰菊酯(Fe_2)和血蓝蛋白(Cu2))和单加氧酶(如甲烷单加氧酶(Fe_2或Cun))的功能模型。为了合成双铁-双氧络合物，重要的是控制适宜于两个铁离子与O_2结合的配位环境，并使过氧钼物种稳定在不可逆氧化状态。为此目的，我们开发了一系列具有空间受阻的吡啶和咪唑基的双核配体，其N_6O给电子体上带有酚基或烷氧基桥基。它们形成五配位的双核[Fe_2(L)(RCO_2)]^&lt；2+&gt；并带有一个外来的…更多的常量羧酸桥，与O_2反应形成过氧物种。研究发现，这些配合物的不可逆氧化热稳定性和氧亲和力高度依赖于二核配体和桥联羧酸盐的立体化学和电子给体能力。最后，我们成功地合成了顺式-MU-1，2-过氧基二铁配合物，这是第一个在室温下与O_2可逆结合的结晶学表征的二铁二氧络合物。双铜配合物：合成了一系列具有三脚架四齿配体的铜(I)配合物((R_1R_2NCH_2CH_2CH_2)_3N：L)。考察了它们与O_2的反应活性。它们在低温下形成反式-Mu-1，2-过氧基物种。研究发现，氧配合物的立体化学和热稳定性高度依赖于取代基(R)的空间体积。我们成功地表征了一种反式-MU-1，2-过氧基团([Cu((BnHNCH_2CH2)_3N)]_2(O_2))，其中苄基(Bn)基团在Cu^&lt；2+&gt；-O_2^&lt；2-&gt；-Cu^&lt；2+&gt；基团周围形成空腔，稳定了过氧基团。较少

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