Two homoleptic copper(II) complexes [Cu(L1)₂] and [Cu(L2)₂] with anionic redox-active ligands were synthesised, one with urea azine (L1) and the other with thio-urea azine (L2) ligands. One-electron oxidation of the complexes initiates an unprecedented redox-induced electron transfer process, leading to monocationic copper(I) complexes [Cu(L1)₂]⁺ and [Cu(L2)₂]⁺ with two oxidised ligands. While [Cu(L1)₂]⁺ is best described as a Cu^I complex with two neutral radical ligands that couple antiferromagnetically, [Cu(L2)₂]⁺ is a Cu^I complex with two clearly different ligand units in the solid state and with a magnetic susceptibility close to a diamagnetic compound. Further one-electron oxidation of the complex with L1 ligands results in a dication [Cu(L1)₂]²⁺, best described as a Cu^I complex with a twofold oxidised, monocationic ligand and a neutral radical ligand. The stability in at least three redox states, the accumulation of spin density at the ligands and the facile ligand-metal electron transfer make these complexes highly attractive for a variety of applications; here the catalytic aerobic oxidation of alcohols to aldehydes is tested.

中文翻译：

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具有两个不成对电子的铜 (I) 配合物，通过氧化具有两个氧化还原活性配体的铜 (II) 配合物合成

合成了两种具有阴离子氧化还原活性配体的均配铜(II)配合物[Cu(L1) ₂ ]和[Cu(L2) ₂ ]，一种具有脲嗪(L1)，另一种具有硫脲嗪(L2)配体. 复合物的单电子氧化引发了前所未有的氧化还原诱导电子转移过程，导致单阳离子铜 (I) 复合物 [Cu(L1) ₂ ] ⁺和 [Cu(L2) ₂ ] ⁺与两个氧化配体。虽然 [Cu(L1) ₂ ] ⁺最好描述为具有两个反铁磁耦​​合的中性自由基配体的 Cu ^{I 配合}物，但 [Cu(L2) ₂ ] ⁺是 Cu ^I具有两个明显不同的固态配体单元的复合物，并且具有接近抗磁性化合物的磁化率。与 L1 配体的配合物进一步单电子氧化导致双阳离子 [Cu(L1) ₂ ] ²⁺，最好描述为具有双重氧化的单阳离子配体和中性自由基配体的 Cu ^I配合物。至少三种氧化还原状态的稳定性、配体处自旋密度的积累以及配体-金属电子转移的简便性使这些配合物对各种应用极具吸引力；这里测试了醇催化有氧氧化为醛的过程。