Chiral Arrangement of Achiral Au Nanoparticles by Supramolecular Assembly of Helical Nanofiber Templates
作者:Sung Ho Jung、Jiwon Jeon、Hyungjun Kim、Justyn Jaworski、Jong Hwa Jung
DOI:10.1021/ja5018199
日期:2014.4.30
hydrogel templates. Controlled growth of gold nanoparticles at spatially arranged locations along the nanofiber is achieved by UV reduction of Au(I) ions on the supramoleculartemplates. The resulting materials were found to have significant interparticle interactions and well-defined helicity to provide high quality, chiroptically active materials. With this novel approach, the tailored assembly of nanoparticle
NMR detection of chirality and enantiopurity of amines by using benzene tricarboxamide-based hydrogelators as chiral solvating agents
作者:Sung Ho Jung、Ka Young Kim、Ahreum Ahn、Shim Sung Lee、Myong Yong Choi、Justyn Jaworski、Jong Hwa Jung
DOI:10.1039/c6nj01543c
日期:——
Enantiomericexcess of chiral compounds is a key parameter that can influence their activity or therapeutic action. Current approaches to the rapid measurement of enantiomericexcessusing 1H NMR is based on the formation of diastereomeric complexes between chiral analytes and a chiral host, leading to two species with no symmetry relationship. Here, we demonstrate that a gelator host system can provide
手性化合物的对映体过量是可以影响其活性或治疗作用的关键参数。当前使用1 H NMR快速测量对映体过量的方法是基于在手性分析物和手性主体之间形成非对映异构体,导致两种不对称的物质。在这里,我们证明了胶凝剂宿主系统可以提供一种方法,以根据手性胺的客体混合物的相应对映体过量,在二胺或单胺混合物的1 H核磁共振(NMR)中引发不同的化学位移。这些胶凝剂宿主为客体胺的手性和对映体纯度提供了一个基于NMR的评估实例。
Synthesis and photocatalytic activities of two homochiral metal–organic frameworks with cages and hydrogen bonding helices
Two homochiral metal–organicframeworks (HMOFs) based on flexible alanine-derived ligands have been synthesized successfully, which possess M3L2 cages and interesting hydrogen bonding helices and exhibit excellent photocatalytic activity on the degradation of methylene blue.
已成功合成了两个基于柔性丙氨酸衍生配体的同手性金属有机骨架(HMOF),它们具有M 3 L 2笼和有趣的氢键螺旋,并且对亚甲基蓝的降解表现出出色的光催化活性。
Structure, adsorption and magnetic properties of chiral metal–organic frameworks bearing linear trinuclear secondary building blocks
The reactions of new chiral organic ligands trimesoyltri(L-alanine) (L-TMTAH3) or trimesoyltri(D-alanine) (D-TMTAH3) with transition metal salts in the presence of an ancillary ligand of 4,4â²-bipyridine gave two pairs of three dimensional frameworks [Co3(L-TMTA)2(4,4â²-bpy)4]·28H2O (1), [Co3(D-TMTA)2(4,4â²-bpy)4]·28H2O (2) [Ni3(L-TMTA)2(4,4â²-bpy)4]·2C2H5OH·14H2O (3) and [Ni3(D-TMTA)2(4,4â²-bpy)4]·2C2H5OH·14H2O (4). These compounds were characterized by elemental analysis, IR, and X-ray powder diffraction analysis and the structures of 1â3 were determined from X-ray single crystal diffraction analysis. Complexes 1â4 feature linear trinuclear secondary building blocks [M3(COO)4]2+ formed via the connection of three metal ions by four carboxylato groups from four TMTA3â ligands. Every adjacent two linear trinuclear secondary building blocks are linked by one and three 4,4â²-bipyridine molecules along the a and c axis, respectively, to form two-dimensional sheets, which are further connected by TMTA3â ligands to construct a porous three dimensional framework with one-dimensional channels. Compound 3 was taken as an example to investigate the adsorption properties of compounds 1â4. It revealed a saturated hydrogen uptake of 216.6 cm3 gâ1 (2.0wt%) at 11.1 atm measured at 77 K, a maximum CO2 uptake of 119.4 cm3 gâ1 (23.5wt%) at 19.5 atm measured at 298 K and a saturated CH4 uptake of 77.8 cm3 gâ1 (5.6wt%) at 27.1 atm measured at 298 K. The magnetic studies of complexes 1 and 3 indicate the presence of antiferromagnetic interactions between the metal ions in the two compounds.
新的手性有机配体三甲酰三(L-丙氨酸)(L-TMTAH3)或三甲酰三(D-丙氨酸)(D-TMTAH3)与过渡金属盐在辅助配体 4、4,4â²-联吡啶的辅助配体存在的情况下,过渡金属盐与三甲基三(D-丙氨酸)(D-TMTAH3)产生了两对三维框架[Co3(L-TMTA)2(4,4â²-bpy)4]Â-28H2O(1)、[Co3(D-TMTA)2(4、4â²-bpy)4]Â-28H2O (2)、[Ni3(L-TMTA)2(4,4â²-bpy)4]Â-2C2H5OHÂ-14H2O (3)和[Ni3(D-TMTA)2(4,4â²-bpy)4]Â-2C2H5OHÂ-14H2O (4)。通过元素分析、红外光谱和 X 射线粉末衍射分析对这些化合物进行了表征,并通过 X 射线单晶衍射分析确定了 1â3 的结构。配合物 1â4 具有线性三核二级结构单元 [M3(COO)4]2+,由四个 TMTA3â 配体的四个羧基连接三个金属离子而形成。每相邻两个线性三核二级结构单元分别由一个和三个 4,4â²-联吡啶分子沿 a 轴和 c 轴连接,形成二维薄片,再由 TMTA3â 配体进一步连接,构建出具有一维通道的多孔三维框架。以化合物 3 为例,研究了化合物 1â4 的吸附特性。在 77 K 温度下,11.1 atm 的饱和氢气吸附量为 216.6 cm3 gâ1 (2.0wt%);在 298 K 温度下,19.5 atm 的最大二氧化碳吸附量为 119.4 cm3 gâ1 (23.5wt%);饱和甲烷吸附量为 77.对复合物 1 和 3 的磁性研究表明,这两种化合物中的金属离子之间存在反铁磁相互作用。
Asymmetric induction in homochiral MOFs: from interweaving double helices to single helices
作者:Xin Wu、Hua-Bin Zhang、Zhong-Xuan Xu、Jian Zhang
DOI:10.1039/c5cc06501a
日期:——
A pair of homochiral metal–organic frameworks with interweaving double helices from enantiopure ligands and single helices braided by 4,4′-bipyridine and cadmium clusters have been synthesized successfully as a result of asymmetric induction.