Donor regulation of donor-acceptor MOF toward more accessible photocatalyst for effective singlet oxygen-based photooxidation

Singlet oxygen (1O2) is recognized as one of the most effective and selective oxygen agents. However, the explorative study of photocatalysts (PCs) for effective 1O2-based photocatalytic oxidation remains challenging and critical. In this study, a novel donor-acceptor metal-organic framework (D-A MOF) has been developed by engineering the D-A system, which was then evaluated as a photocatalyst for 1O2-based oxidation. By regulating the donor component of the D-A systematic framework, the MOF (B1) exhibits delayed fluorescence (DF) behavior with a reduced singlet-triplet gap. Given the significantly improved electron transfer behavior in combination with an efficient energy transfer process, the optimal B1 demonstrates remarkable activity toward 1O2 generation under suitable photoexcitation conditions. Therefore, it can be utilized for the photocatalytic oxidation of 1,5-dioxynaphthalene (1,5-DHN) to Juglone, achieving the highest yield (conversion > 99% at 25 °C in 30min) and selectivity among all previously reported MOF photocatalysts.