Four metal–organic frameworks built from distinct secondary building blocks: Syntheses, structures, photoluminescence and photocatalytical properties

Four metal–organic frameworks (MOFs), namely [Cu4(L)2(μ3-OH)2(CH3OH)2(H2O)] (1), [Co2(L)(μ3-OH)(H2O)2] (2), [Cd2(L)(μ3-OH)(H2O)2] (3) and [Cd9(L)4(μ3-OH)4(CH3O)2(H2O)2]·(H2O)·2(CH3OH) (4) where H3L = (3,5-dicarboxyl-phenyl)-(4-(2′-carboxyl-phenyl)-benzyl) ether, have been prepared. Compound 1 displays a (3,6)-connected net with kgd (kagome dual) topology based on discrete {Cu4} secondary building blocks. Compounds 2 and 3 possess similar two-dimensional (2D) structures, which are constructed by L anions and rod-shaped SBUs. In compound 4, neighboring {Cd9} units are bridged by carboxylate groups to build a rod-shaped SBU. These SBUs are further extended by L anions into a 3D framework. The optical band gaps of 1 and 2 and the photoluminescent behaviors of 3 and 4 have been investigated. In addition, the photocatalytic activities of compounds 1 and 2 have been estimated under UV irradiation.

Graphical abstractFour metal–organic frameworks based on a flexible acid have been synthesized. The photocatalytical properties of compounds 1 and 2 and photoluminescent behaviors of 3 and 4 have been investigated.Figure optionsDownload full-size imageDownload as PowerPoint slide