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

摘要

Four metal-organic frameworks (MOFs), namely [Cu4(L)_2(μ_3-OH)_2(CH_3OH)_2(H_2O)] (1), [Co_2(L) (μ_3-OH)(H_2O)_2] (2), [Cd_2(L)(μ_3-OH)(H_2O)_2] (3) and [Cd_9(L)_4(μ_3-OH)_4(CH_3O)_2(H_2O)_2]?(H_2O)?2(CH_3OH) (4) where H_3L = (3,5-dicarboxyl-phenyl)-(4-(20-carboxyl-phenyl)-benzyl) ether, have been prepared. Compound 1 displays a (3,6)-connected net with kgd (kagome dual) topology based on discrete {Cu_4} 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 {Cd_9} 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.