A multi-responsive luminescent sensor for organic small-molecule pollutants and metal ions based on a 4d–4f metal–organic framework

Abstract

Two silver(I)–lanthanide(III) heterometallic-organic frameworks (HMOFs) {[Ln₃Ag₃(BPDC)₅(OX)(H₂O)₇]·7H₂O}_n (Ln = Tb (1), Gd (2)) have been synthesized via a mixed ligand approach using 2,2′-bipyridine-3,3′-dicarboxylic acid (H₂BPDC) and oxalic acid (H₂OX) under hydrothermal conditions. Single crystal X-ray diffraction studies showed a (3,4,5)-connected new topology of {3·4²·5·6²}{3·4³·5²·6³·7}{3·5·6²·9·10}{4²·5·6³}{4²·5}{4²·6}{4³·5·6²}{4³·6³}{4³·6⁴·8²·10}. Luminescence studies showed that the characteristic emissions of Tb³⁺ ions are observed in HMOF 1 which can be capable of sensing organic small-molecule pollutants and metal ions. In addition, it can also discriminate the isomers of pentanol as well as quantitatively distinguish benzendiamines which are carcinogenic but used for hair coloring.