Tunable colors and white-light emission based on a microporous luminescent Zn(ii)-MOF

Abstract

Metal–organic frameworks (MOFs) are a rapidly growing class of hybrid materials with many multifunctional properties. The permanent porosity plays a central role in the functional properties. In particular, the luminescent MOFs with a permanent porosity have wide applications in guest species recognition and adsorption. In this contribution, we aim to develop tunable colors and white-light luminescence materials by the encapsulation of Ln³⁺ species in microporous luminescent MOFs. A semi-rigid trivalent carboxylic acid 1,3,5-tri(4-carboxyphenoxy)benzene (H₃TCPB) was selected as the organic building block, not only because it is suitable to construct microporous frameworks, but also by reason of its blue luminescent emission. Under solvothermal reactions, a microporous MOF material, [Zn₃(TCPB)₂(H₂O)₂]·2H₂O·4DMF (JUC-113, JUC = Jilin University, China), was synthesized, which has a permanent porosity and emits blue light. According to three-primary colors, the guest luminescent species should be Tb³⁺ and Eu³⁺ owing to their distinctive colors (Tb³⁺, green; Eu³⁺, red). In addition, the luminescent properties of JUC-113 can be easily tuned by different combinations of the encapsulation amount of Tb³⁺ and Eu³⁺, obtaining white-light emission materials.