title: Syntheses, structures, photoluminescence, photocatalysis, and photoelectronic effects of 3D mixed high-connected metal-organic frameworks based on octanuclear and dodecanuclear secondary building units.
abstract: Four novel metal-organic frameworks (MOFs) based on high-nuclear metal carboxylate clusters, namely, [Zn(4)(L)(2)(μ(3)-OH)(2)(H(2)O)(1.5)]·2H(2)O (1), [Zn(5)Na(L)(2)(μ(3)-OH)(4)(CH(3)CH(2)O)(H(2)O)(2)] (2), [Cd(4)(L)(2)(BIME)(0.5)(μ(3)-OH)(2)(H(2)O)(1.5)]·2H(2)O (3), and [Zn(4)(L)(2)(BET)(0.5)(μ(3)-OH)(2)(H(2)O)] (4), where H(3)L = (3,5-dicarboxyl-phenyl)-(4-(2'-carboxyl-phenyl)-benzyl)ether, BET = 1,1'-(2'-oxybis(ethane-2,1-diyl))bis(1,2,4-triazol-1-yl), BIME = 1,2-bis(imidazol-1-yl)ethane, have been synthesized under hydrothermal conditions. In 1, each planar octanuclear zinc cluster [Zn(8)(μ(3)-OH)(8)(CO(2))(12)(H(2)O)(3)] is linked by twelve L anions to give an unusual (3,12)-connected framework with (4(3))(2)(4(20)·6(28)·8(18)) topology. In 2, dodecanuclear heterometallic clusters [Zn(10)Na(2)(μ(3)-OH)(8)(CO(2))(12)(CH(3)CH(2)O)(2)(H(2)O)(4)] are surrounded by twelve L anions to form a (3,12)-connected net with the same topology as 1. However, 3 exhibits a rare (3,14)-connected (4(3))(3(2)4)(3(4)·4(20)·5(14)·6(34)·7(11)·8(8)) net based on octanuclear cadmium cluster [Cd(8)(BIME)(2)(μ(3)-OH)(4)(CO(2))(12)(H(2)O)(4)]·2H(2)O as a 14-connected node and H(3)L as a 3-connected node. In 4, each octanuclear zinc cluster [Zn(8)(BET)(2)(μ(3)-OH)(4)(CO(2))(12)(H(2)O)(2)] is linked by twelve L anions to furnish a (3,14)-connected net with the same topology as 3. The optical energy gaps and photoluminescence were investigated for the compounds. Moreover, compounds 1-4 exhibit good photocatalytic activities for degradation of methylene blue (MB) under UV irradiation and show good stability towards UV photocatalysis. In addition, 1 and 4 display a photocurrent density under several on-off cycles of illumination.
authors.affiliation: Key Lab of Polyoxometalate Science, Department of Chemistry, Northeast Normal University, Changchun 130024, People's Republic of China.
authors.forename: Peng
authors.initials: P
authors.lastname: Du
authors.forename: Yan
authors.initials: Y
authors.lastname: Yang
authors.forename: Jin
authors.initials: J
authors.lastname: Yang
authors.forename: Bing-Kun
authors.initials: BK
authors.lastname: Liu
authors.forename: Jian-Fang
authors.initials: JF
authors.lastname: Ma
mesh_terms: D002264:Carboxylic Acids / Q000737:chemistry*; D002384:Catalysis; D056831:Coordination Complexes / Q000138:chemical synthesis* / Q000737:chemistry; D018360:Crystallography, X-Ray; D008163:Luminescent Measurements; D008751:Methylene Blue / Q000737:chemistry; D008968:Molecular Conformation; D014466:Ultraviolet Rays; D015032:Zinc / Q000737:chemistry*
chemical_list: D002264:Carboxylic Acids; D056831:Coordination Complexes; D015032:Zinc; D008751:Methylene Blue