Discrete polynuclear manganese nanorods: syntheses, crystal structures and magnetic properties
作者:Jian-Jun Liu、Yao Wang、Shu-Ting Wu、Mei-Jin Lin、Chang-Cang Huang、Wen-Xin Dai
DOI:10.1039/c4ra07015a
日期:——
Shape-anisotropic nanomaterials with uniform lengths and widths have attracted much interest but few of them are involved in self-assembled manganese complexes. The combination of two redox-active acylthiosemicarbazide ligands with Mn3+ cations leads to two discrete polynuclear Mn nanorods, pentanuclear [Mn5(L3)6][Mn0.7(DMF)1.4(H2O)2.8] (1a) and trinuclear Mn3(L4)3·2DMF (2), whose L3 and L4 represent N-(5-(2-hydroxyphenyl)-1,3,4-oxadiazol-2-yl)benzamide and N-(5-(2-hydroxyphenyl)-1,3,4-oxadiazol-2-yl)-propionamide, respectively, which are in situ synthesized from their acylthiosemicarbazide derivatives in the presence of Mn3+ cations, while the latter are reduced into divalent ones in rod-like moieties. For each pentanuclear anion in 1a, the charge is balanced by a solvated trivalent manganese cation, which can be replaced by two tetramethylammonium cations to yield pure valence compound 1b. Moreover, the magnetic studies reveal all of them possess antiferromagnetic properties.
具有均匀长度和宽度的形状各向异性纳米材料引起了人们的广泛兴趣,但其中很少涉及自组装锰配合物。将两种具有氧化还原活性的酰基硫代氨基甲酸配体与 Mn3+ 阳离子结合,可得到两种离散的多核锰纳米棒,即五核 [Mn5(L3)6][Mn0.7(DMF)1.4(H2O)2.8] (1a) 和三核 Mn3(L4)3-2DMF (2),其中 L3 和 L4 分别代表 N-(5-(2-羟基苯基)-1,3,4-恶二唑-2-基)苯甲酰胺和 N-(5-(2-羟基苯基)-1,3,4-恶二唑-2-基)丙酰胺、分别由其酰基硫代氨基氮衍生物在 Mn3+ 阳离子存在下原位合成,而后者则在棒状分子中还原成二价阳离子。对于 1a 中的每个五核阴离子,其电荷都由一个溶解的三价锰阳离子来平衡。此外,磁性研究显示它们都具有反铁磁性。