title: Porous anionic, cationic, and neutral metal-carboxylate frameworks constructed from flexible tetrapodal ligands: syntheses, structures, ion-exchanges, and magnetic properties.
abstract: A series of coordination polymers with anionic, cationic, and neutral metal-carboxylate frameworks have been synthesized by using a flexible tetrapodal ligand tetrakis[4-(carboxyphenyl)oxamethyl] methane acid (H(4)X). The reactions between divalent transition-metal ions and H(4)X ligands gave [M(3)X(2)]·[NH(2)(CH(3))(2)](2)·8DMA (M = Co (1), Mn (2), Cd(3)) which have anionic metal-carboxylate frameworks with NH(2)(CH(3))(2)(+) cations filled in channels. The reactions of trivalent metal ions Y(III), Dy(III), and In(III) with H(4)X ligands afforded cationic metal-carboxylate frameworks [M(3)X(2)·(NO(3))·(DMA)(2)·(H(2)O)]·5DMA·2H(2)O (M = Y(4), Dy(5)) and [In(2)X·(OH)(2)]·3DMA·6H(2)O (6) with the NO(3)(-) and OH(-) serving as counterions, respectively. Moreover, a neutral metal-carboxylate framework [Pb(2)X·(DMA)(2)]·2DMA (7) can also be isolated from reaction of Pb(II) and H(4)X ligands. The charged metal-carboxylate frameworks 1-5 have selectivity for specific counterions in the reaction system, and compounds 1 and 2 display ion-exchange behavior. Moreover, magnetic property measurements on compounds 1, 2, and 5 indicate that there exists weak antiferromagnetic interactions between magnetic centers in the three compounds.
authors.affiliation: State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fujian, Fuzhou, 350002, PR China.
authors.forename: Tian-Fu
authors.initials: TF
authors.lastname: Liu
authors.forename: Jian
authors.initials: J
authors.lastname: Lü
authors.forename: Chongbin
authors.initials: C
authors.lastname: Tian
authors.forename: Minna
authors.initials: M
authors.lastname: Cao
authors.forename: Zujin
authors.initials: Z
authors.lastname: Lin
authors.forename: Rong
authors.initials: R
authors.lastname: Cao
mesh_terms: D000838:Anions / Q000737:chemistry; D002264:Carboxylic Acids / Q000737:chemistry*; D002412:Cations / Q000737:chemistry; D018360:Crystallography, X-Ray; D008024:Ligands; D008280:Magnetics; D019216:Metals, Heavy / Q000737:chemistry*; D008958:Models, Molecular; D009942:Organometallic Compounds / Q000138:chemical synthesis* / Q000737:chemistry*; D016062:Porosity; D013499:Surface Properties
chemical_list: D000838:Anions; D002264:Carboxylic Acids; D002412:Cations; D008024:Ligands; D019216:Metals, Heavy; D009942:Organometallic Compounds