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From Interwoven to Noninterpenetration: Crystal Structural Motifs of Two New Manganese–Organic Frameworks Mediated by the Substituted Group of the Bridging Ligand

2007; Wiley; Volume: 2008; Issue: 4 Linguagem: Inglês

10.1002/ejic.200700818

1099-0682

Zhiyong Fu, Jianglong Yi, Yuan Chen, Shijun Liao, Ning Guo, Jing‐Cao Dai, Guo-Dong Yang, Yun-Xia Lian, Xin‐Tao Wu,

Lanthanide and Transition Metal Complexes

Abstract The respective reactions of the Mn II ion with the homologous ligands 2‐aminoterephthalic acid and terephthalic acid afforded two novel manganese–organic compounds, [Mn(2‐atp)(bipy‐eta) 0.5 ] n ( 1 ) and {[Mn(tp)(bipy‐eta) 1.5 ] · 2H 2 O} n ( 2 ). These two compounds were characterized by IR spectroscopy, elemental analysis, and single‐crystal X‐ray diffraction. Compound 1 (C 14 H 11 MnN 2 O 4 ) belongs to the monoclinic C2 space group, Z = 4 [ a = 11.9355(9) Å, b = 15.522(1) Å, c = 7.9542(6) Å, β = 112.591(2)°], whereas compound 2 (C 26 H 26 MnN 3 O 6 ) belongs to the monoclinic P 2 1 / c space group, Z = 4 [ a = 10.0330(3) Å, b = 11.9454(1) Å, c = 21.8640(5) Å, β = 92.842(2)°]. Both compounds have bimetallic blocks as basic units. With two bridging carboxylate groups, the Mn ··· Mn separation in compound 2 is 4.841 Å. By contrast, the distance of the Mn ··· Mn centers in compound 1 (with the first paddle‐like manganese core) is shortened to 3.058 Å by the bridging of four carboxylate groups, which suggests the existence of a Mn–Mn single bond. The paddle‐wheel clusters in compound 1 aggregate into a 3D modular framework that interpenetrates in a threefold manner. The binuclear units in 2 extend to a 3D network with a novel bilayer structural motif. The inclusion of the bipy‐eta molecules prevents the structure of 2 from being interwoven, and it thus adopts a noninterpenetrating arrangement. The results indicate that variations in the molecular self‐assembly are influenced by the substituted group in the bridging ligand.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)