Photochromic polyoxometalate/naphthalenediimide hybrid structure with visible-light-driven dye degradation

A feasible method to construction multifunctional hybrid compounds is the incorporation of appropriate functional inorganic and organic components through self-assembly. Naphthalene diimides (NDIs) and polyoxometalates (POMs) are two versatile building blocks that have been used in many fields. In this paper, self-assembly of electron-deficient NDI ligand and POM resulted in an organic-inorganic hybrid compound, [Ce2(BINDI)(DMF)8]·[Mo6O19] (1), (H4BINDI = N, N′-bis(5-isophthalic acid)-1,4,5,8-naphthalene diimide), with segregated Mo6O192− polyanions and two-dimensional cationic coordination network. Because of the photochemical activities of organic and inorganic components, this hybrid compound exhibits interesting reversible photochromic behavior under ultraviolet–visible light irradiation. XRD, EPR, and XPS studies demonstrated that the photochromic behavior resulting from the coaction of NDI and Mo6O192− polyanions. Moreover, this hybrid material shows excellent photocatalytic degradation activity toward the methylene blue (MB) dye under visible light irradiation.