화학공학소재연구정보센터
Inorganic Chemistry, Vol.59, No.2, 1284-1294, 2020
Triggering Lewis Acidic Nature through the Variation of Coordination Environment of Cd-Centers in 2D-Coordination Polymers
The rational design and successful synthesis of novel functional metal organic frameworks relies on careful selection of metals and versatile organic ligands. A newly designed pyrazole-based dicarboxylate ligand, 5-(3,5-dimethy1-1H-pyrazol-1-71) 1,3-benzene-dicarboxylic acid (H2L), was utilized to obtain two new Cd-based coordination polymers I [Cd(L)(H2O)]center dot H2O and II [Cd(L)] under similar reaction conditions via solvothermal strategy. Single-crystal X-ray data confirmed that compound I exhibits a two-dimensional (2D) skeleton comprising pentagonal bipyramidal Cd-ions and an organic ligand moiety. Compound II has also formed a two-dimensional layer arrangement with the connectivity between trigonal bipyramidal Cd-ions and the organic ligand. Topological analysis revealed that compound I has formed unique 4(3).6(3) net topology while compound II has displayed a 4(4).6(2) sql net topology with 2D frameworks. The Lewis acidic nature of both I and II containing a Cd2+ metal center has been correlated with the coordination number through dye adsorption-desorption and catalysis studies. The selective adsorption of anionic dye and the extent of adsorption are interrelated with the Cd-ion geometry. For the first time, the role of coordinated water molecule has been analyzed through heterogeneous catalysis reaction (i.e., cyanosilylation) with Cd-based 2D coordination polymers (CPs). The plausible mechanisms have been proposed to explain the subsequent role of coordination number and environment in CPs.