Stable luminescent metal-organic frameworks as dual-functional materials to encapsulate ln(3+) ions for white-light emission and to detect nitroaromatic explosives.

A stable porous carbazole-based luminescent metal–organic framework, NENU-522, was successfully constructed. It is extremely stable in air and acidic/basic aqueous solutions, which provides the strategy for luminescent material encapsulation of Ln3+ ions with tunable luminescence for application in light emission. More importantly, Ln3+@NENU-522 can emit white light by encapsulating different molar ratios of Eu3+ and Tb3+ ions. Additionally, Tb3+@NENU-522 is found to be useful as a fluorescent indicator for the qualitative and quantitative detection of nitroaromatic explosives with different numbers of −NO2 groups, and the concentrations of complete quenching are about 2000, 1000, and 80 ppm for nitrobenzene, 1,3-dinitrobenzene, and 2,4,6-trinitrophenol, respectively. Meanwhile, Tb3+@NENU-522 displays high selectivity and recyclability in the detection of nitroaromatic explosives.