Investigations of dioxygen activation mechanisms by dimetal complexes

合成了一系列具有三脚架四齿配体(L)的铜(I)配合物([Cu(L)]^+)，并研究了它们与氧的反应活性。铜(I)配合物[Cu(L)]~+反应生成双(μ-氧代)二铜(III)络合物，可通过N_2气泡转化为铜(I)络合物。此外，还发现双(μ-氧代)二铜(III)络合物对支撑配体具有单加氧酶活性。反应活性可以通过支撑配体的立体化学电子效应来调节：与H_2O_2和GT反应生成的具有多种双氧活性物种的镍络合物的反应中间体；含有一系列具有甲基取代基的四齿三脚架配体的双(μ-羟基)Ni(II)_2与H_2O_2在低温下反应生成双(μ-氧代)Ni(II)_2a-双(μ-超氧基)Ni(II)_2和双(μ-烷基过氧基)Ni(II)_2络合物作为配体甲基取代基向羧酸盐和烷氧配体&lt转化的中间体；合成了过氧碳酸铁(III)配合物[Fe(Qn)2(O_2C(O)O)]^-(1)。络合物在-35℃的乙腈溶液中稳定，而在20℃时分解。用共振拉曼光谱和电喷雾质谱研究了[Fe(qn)_2(^&lt；18&gt；O-^&lt；18&gt；OC(O)O)]^-complex(1-^&lt；18&gt；O-^&lt；18&gt；O&gt；O)在20℃的乙腈溶液中的分解。结果表明，过氧碳酸配体的^&lt；18&gt；O-^&t；O在热分解过程中通过^&lt；16&gt；O-^&lt；18&gt；OC(O)O和^&lt；18&gt；OC(O)O转化为^&lt；16&gt；O-^&lt；16&gt；OC(O)O。这是第一个显示铁络合物可逆O-O键断裂和形成的例子

<Reversible four electron redox conversion of dioxygen by copper complexes > A series of copper(I) complexes ([Cu(L)]^+) having tripodal tetradentate ligands (L) was synthesized and reactivity of their complexes with O_2 was investigated. Reaction of copper(I) complexes ([Cu(L)]^+ generated bis(μ-oxo)dicopper(III) complexes, which showed reversible conversion to copper(I) complexes by bubbling of N_2. Furthermore, it was also found that bis(μ-oxo)dicopper(III) complexes have monooxygenase activity for the supporting ligands. Reactivity can be modulated by stereochemical electronic effect of the supporting ligands<Reaction intermediates of nickel complexes having a variety of dioxygen active species formed by the reaction with H_2O_2> Reaction of a bis(μ-hydroxo)Ni(II)_2 having a series of tetradentate tripodal ligands having methyl substituents with H_2O_2 at low temperature resulted in a successive formation a bis(μ-oxo)Ni(III)_2 a bis(μ-superoxo)Ni(II)_2, and a bis(μ-alkylperoxo)Ni(II)_2 complexes as the intermediates for the conversion of a methyl substituent of ligands to carboxylate and alkoxide ligands<Reversible O-O bond cleavage and formation of a peroxo group of an iron(III) complex having a peroxycarbonate> A peroxcarbonate iron(III) complex ([Fe(qn)_2(O_2C(O)O)]^-(1)) was synthesized. The complex is stable at -35℃ in acetonitrile, whereas it decomposes at 20℃. Decomposition of an ^<18>O-labeled [Fe(qn)_2(^<18>O-^<18>OC(O)O)]^-complex (1-^<18>O-^<18>O) at 20℃ in acetonitrile was investigated by resonace Raman and ESI-MS spectroscopies. They revealed that the ^<18>O-^<18>O of the peroxocarboante ligand is converted through ^<16>O-^<18>OC(O)O and ^<18>O-^<16>OC(O)O to ^<16>O-^<16>OC(O)O during thermal decomposition. This is the first example which showed reversible O-O bond cleavage and formation for iron complexes