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

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.