Synthesis, crystal structures, and magnetic properties of two three-dimensional octacyanotungstate(Ⅳ)-based bimetallic frameworks with 4,4'-bipyridine dioxide (4,4'-dpdo)

• 来源期刊: 中国科学B辑（英文版）
• 年，卷（期）: 2009,（3）
• 页码范围: 266-275
• 页数: 10页
• 语种: 英文
• DOI: 10.1007/s11426-009-0050-y

摘要

The reaction of [HN(n-C4H9)3]3[WⅤ(CN)8]·4H2O, 4,4'-bipyridine dioxide(4,4'-dpdo), end MnCl2·4H2O or crystallizes in the orthorhombic system, space group P21212 with cell constants α=10.397(2) A, b=11.321(2) A, c=12.295(3) A and Z=2, whereas 2 crystallizes in the monoclinic system, space group P21/c with cell constants a=13.038(3) A, b=13.784(3) A, c=13.225(3) A, β=93.44(3)g and Z=4. In complex 1, each [WⅣ(CN)8]4- unit with a square antiprismatic geometry is connected to four Mn2 dimers through four bridging CN- ions forming wavelike alternating -W-Mn2-W-Mn2- layers, which are further linked through 4,4'-dpdo ligands coordinated to the Mn ions into a three-dimensional open framework. In complex 2, each [WⅣ(CN)8]4- ion still adopts a square antiprismallc geometry, whereas it bonds to seven copper ions through seven CN- ions leading to cage-like undulate layers further bridged by 4,4'-dpdo ligands into a three-dimensional network. Due to the bridging role of the long rigid 4,4"-dpdo ligand, there exist plenty of large cavities in the open frameworks of complexes 1 and 2 occupied by solvent clusters containing H2O or CH3OH molecules. To our knowledge, it is noted that 4,4'-dpdo displays a μ-4,4,4',4' mode, which was first experimentally observed, although predicted before. Magnetic studies show that complex 1 displays an antiferromagnetic coupling between MnⅡ ions, while complex 2 ex-hibits a weak ferromagnetic interaction between CuⅡ ions.