Barium Carboxylate Metal–Organic Framework – Synthesis, X‐ray Crystal Structure, Photoluminescence and Catalytic Study

Abstract

Abstract A new 3D alkaline earth metal–organic framework (MOF), [Ba(Hdcp)H 2 O] n ( 1 ) (H 3 dcp = 3,5‐pyrazoledicarboxylic acid), has been hydrothermally synthesized and structurally characterized by single‐crystal X‐ray diffraction analysis. A crystallographic study reveals that each metal ion in 1 is coordinated by eight O atoms and one N atom. Each 3,5‐pyrazoledicarboxylato (Hdcp 2– ) ligand coordinates to six alkaline earth metal centers through two carboxylate groups, each of which adopts a μ 3 ‐η 2 :η 1 ‐bridging coordination mode to afford a 3D network. Thermogravimetric analysis reveals that 1 is thermally stable up to ca. 230 °C. An emission band at ca. 466 nm ( λ max ) was observed in the photoluminescence spectrum of 1 in the solid state at room temperature. Compound 1 heterogeneously catalyzes the aldol condensation reactions of various aromatic aldehydes with acetone, cyclohexanone, acetophenone, and cyclopentanone.