Supramolecular assembly under the control of the chelating ligand for the MnII/bridging ligands/3-sulfobenzoate system and catalytic properties for the disproportionation of hydrogen peroxide
作者:Xiao-He Miao、Long-Guan Zhu
DOI:10.1039/b9nj00428a
日期:——
Six MnII 3-sulfobenzoate complexes with neutral ligands, [Mn(4,4′-bipy)2(H2O)4](3-sb)·3H2O (1), [Mn(3-sb)(bpe)1.5(H2O)2](bpe)0.5·H2O}n (2), [Mn(3-sb)(phen)(H2O)3](4,4′-bipy)·H2O (3), [Mn2(3-sb)2(phen)2 (4,4′-bipy)(H2O)4] (4), [Mn(3-sb)(phen)2(H2O)] (bpe)0.5·4H2O (5), and [Mn(3-sb)(phen)2(H2O)](bpe)0.5·H2O (6) [where 3-sb is 3-sulfobenzoate, 4,4′-bipy is 4,4′-bipyridine, bpe is 1,2-bis(4-pyridine)ethylene, and phen is 1,10-phenanthroline], were synthesized and characterized by several modern analytic methods. The molecular structures for the six complexes are monomers for complexes 3, 5, and 6, cation–anion species for complex 1, dimer for complex 4, and 1-D polymer for complex 2. The phen ligands in complexes 3 and 4 generate some effects on the hydrogen-bonding network, π–π interactions, and supramolecular assembly. TG analysis showed that desolvated complexes containing 4,4′-bipy are less stable than those of complexes containing bpe ligands. The emission strength order is 1 > 5 > 6 > 3 > 2 > 4, while the UV-vis absorption strengths are 4 > 3 > 1 for complexes containing 4,4′-bipy, and 5 > 6 > 2 for bpe metal complexes. The catalytic experiments showed that these six complexes are catalytically active for the disproportionation of H2O2 in the presence of imidazole and complex 3 has the best catalytic activity.
带有中性配体的六个MnII 3-磺基苯甲酸配合物, [Mn(4,4'-联吡啶)2(H2O)4](3-sb)·3H2O(1), [Mn(3-sb)(bpe)1.5(H2O)2](bpe)0.5·H2O}n(2), [Mn(3-sb)(phen)(H2O)3](4,4'-联吡啶)·H2O(3), [Mn2(3-sb)2(phen)2(4,4'-联吡啶)(H2O)4](4), [Mn(3-sb)(phen)2(H2O)](bpe)0.5·4H2O(5), [Mn(3-sb)(phen)2(H2O)](bpe)0.5·H2O(6)[其中, 3-sb 代表 3-磺基苯甲酸, 4,4'-联吡啶代表 4,4'-联吡啶, bpe 代表 1,2-双(4-吡啶)乙烯, phen 代表 1,10-邻二氮菲)], 通过几种现代分析方法合成和表征。六个配合物的分子结构是:配合物 3, 5 和 6 为单体,配合物 1 为阳离子–阴离子物种,配合物 4 为二聚体,配合物 2 为 1 维聚合物。配合物 3 和 4 中的 phen 配体对氢键网络、π-π相互作用和超分子组装产生一些影响。TG 分析表明,与 bpe 配体配合物相比,去溶剂化的 4,4'-联吡啶配合物稳定性较低。发射强度的顺序为 1 > 5 > 6 > 3 > 2 > 4,而紫外-可见吸收强度为 4 > 3 > 1(4,4'-联吡啶配合物), 5 > 6 > 2(bpe 金属配合物)。催化研究表明,这六个配合物是催化过氧化氢歧化反应的活性催化剂,其中催化活性最好的是配合物 3。