Construction of photoactive MOF for photocatalytic oxidative organic transformation

The incorporation of photoresponsive component into metal-organic frameworks (MOFs) is intriguing because they can confer additional properties such as photomagnetic behavior, light-controlled electrical conductivity, and photocatalysis. Naphthalene diimide (NDI) is organic dye that absorbs visible light and have π-electron-deficient planes and photochemical characteristics. NDIs are ideal for creating photoactive MOF materials due to their ability of undergo reversible single-electron reduction and form stable radical anion. In this work, a photoactive MOF material, Mn2(BNDI)2(DMF)3 (1) (H2BNDI = N,N'-bis(3-benzoic acid) naphthalenediimide), is fabricated and found to exhibit not only notable photochromism (light yellow to dark brown), but also reactive organic radical under ambient conditions. Complex 1 can act as an efficient electron-transfer photocatalyst for selective oxidation of 2,6-di-tert-butylphenol (2,6-DTBP) into various compounds under diverse reaction conditions, without the need for supplementary co-catalysts. Specifically, 2,6-DTBP is photocatalyzed to form 2,6-di-tert-benzoquinone and its dimer in methanol solution, 2,6-DTBP is converted to trimers and 3, 5-di-tert-butyl-4-hydroxybenzaldehyde in ethylene glycol with medium yield. This work will provide new perspective for the fields of NDI-based MOFs and photocatalysis.