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

A new 3D alkaline earth metalorganic framework (MOF), [Ba(Hdcp)H2O]n (1) (H3dcp = 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 (Hdcp2) ligand coordinates to six alkaline earth metal centers through two carboxylate groups, each of which adopts a mu 3-?2:?1-bridging coordination mode to afford a 3D network. Thermogravimetric analysis reveals that 1 is thermally stable up to ca. 230 degrees C. An emission band at ca. 466 nm (?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.