Copper(II)-Silver(I) Macrocyclic Metal-Organic Framework: A Highly Efficient Reusable Triplet Oxygen Collector and...

The generation of highly reactive oxygen (¹O₂) is very significant for a variety of applications such as degradation, bleaching, chemical synthesis, photodynamic therapy for tumor treatment, and others. Herein, we report a novel peroxide-dianion-embedded bimetallic macrocycle, [O₂^2-@Ag₄Cu₄L₄]²⁺ (2), that can completely release the inserted peroxide dianion as the singlet oxygen (¹O₂) via a H⁺-assisted disproportionation process in methanol. Notably, the resulting empty Ag₄Cu₄L₄(ClO₄)₄ (3) is able to trap oxygen (³O₂) from air and fixes it in the macrocycle host as a peroxide dianion; furthermore, it releases it as ¹O₂ again in the presence of H⁺. So, the bimetallic macrocycle [Ag₄Cu₄L₄]⁴⁺ herein behaves as a highly efficient reusable triplet oxygen receptor and singlet oxygen generator.