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A novel Cd( (II)-organic framework [Cd(Hcbic)] n (H 3 cbic = 1-(4-carboxybenz-yl)−1H-benzoim-idazole-5, 6-dicarboxylic acid) was assembled and characterized by X-ray single crystal analysis. The Cd-MOF features one-dimensional left and right-handed double helical chains with screw-pitch of about 4.727 Å and the 4-methyl benzoic acid groups of Hcbic 2− ligands in MOF-1 play many ribbons distributing in the two sides of the 2D networks. It is found that MOF-1 shows high selectivity ( K SV = 1.8 × 10 5 L / mol) for Fe 3+ ions in water solution with luminescent quenching because of the existence of uncoordinated carboxyl groups within open frameworks, which indicates that MOF-1 is a simple and reliable detection sensing reagent for Fe 3+ in practical applications. [ABSTRACT FROM AUTHOR]

Four manganese (II) compounds are obtained by the reaction of manganese salts, triazole-derivatives and auxiliary reagents in aqueous solution or mix-solvents by routine or hydrothermal reactions. X-ray crystal structure analyses reveal that a neutral 0D compound [Mn(Hmctrz) 2 (H 2 O) 2 ] ( 1 ) (H 2 mctrz = 1 H -1,2,4-triazole-3-carboxylic acid) displays a centro-symmetric mononuclear octahedral entity with two Hmctrz − anions and two water molecules; two neutral 2D clusters [Mn(Hdctrz)(H 2 O) 2 ] n ( 2 ) (H 3 dctrz = 1 H -1,2,4-triazole-3,5-dicarboxylic acid) and [Mn 2 (pbtrz)(btca)] n ·4nH 2 O ( 3 ) (pbtrz = 1,3-bis(1,2,4-triazol-1-yl)-propane&H 4 btca = benzene-1,2,4,5-tetracarboxylic acid) possess layer structures with Hdctrz 2 − linkers ( 2 ) and Mn(II)-pbtrz-Mn(II) building blocks periodically extended by μ -btca 4 − connectors ( 3 ); [Mn(pbtrz)] n ·nOAc·nOH ( 4 ) shows a 3D diamond-shaped cationic framework with the anion void volume of 49.2%. Nitrogenous bases are used as the auxiliary ligand in compound 3 and the temple ligand in compounds 1 , 2 , and 4 . Compounds 1 – 4 show antiferromagnetic coupling that has been fitted by different models with the molecular field approximate with D = − 0.129(1) cm −1 for 1 , J = − 0.354(4) cm −1 for 2 and J = − 0.696(6) cm −1 for 3 , respectively. The magnetic differences can be related to different superexchange interactions transmitted by the crystal lattice and/or the zero field splitting (ZFS) of the 6 A 1g single-ion states of 1 and the syn-anti -COO − of 2 as well as the mixed magnetic bridges of μ 1 -O and μ -pbtrz- μ -COO − of 3 . [ABSTRACT FROM AUTHOR]

Careful investigation of the effects of metal ions and pH value resulted in five multi-dimensional metal−organic complexes, [Co 5 ( μ 3 -OH) 2 ( α -bptc) 2 (H 2 O) 6 ] n ( 1 ), {(H 3 O) 2 [Co 4 ( μ 3 -O)( α -bptc) 2 (H 2 O)]·4H 2 O} n ( 2 ), {K 2 [Zn 4 ( μ 3 -OH) 2 ( α -bptc) 2 (H 2 O) 3 ]} n ( 3 ), [Zn 4 ( α -bptc) 2 (H 2 O) 3 ] n ( 4 ), and {[Cd 4 ( α -bptc) 2 (H 2 O) 7 ]·2H 2 O} n ( 5 ) ( α - H 4 bptc = 2,3,3 ' ,4 ' - biphenyl tetracarboxylic acid). The complexes consisted of different highly connected secondary building units (SBUs) assembled via hydrothermal in situ routes. The pH value as well as the kinds of metal ions influenced the coordination modes of α -H 4 bptc and also introduced the hydroxyl ligand at high pH value, resulting in the diversity of SBUs and dimensionality. Variable temperature magnetic measurements indicated the antiferromagnetic behavior in the Co 5 core in 1 , and the intra - chain ferrimagnetic behavior in complex 2 . Moreover, the luminescent properties of the complexes 3 − 5 indicated the existence of intra - ligand charge transfer. [ABSTRACT FROM AUTHOR]