Unprecedented homochiral 3D lanthanide coordination polymers with triple-stranded helical architecture constructed from a rigid achiral aryldicarboxylate ligand
作者:Li-Xin You、Shi-Yu Xie、Cheng-Cai Xia、Shu-Ju Wang、Gang Xiong、Yong-Ke He、Ileana Dragutan、Valerian Dragutan、Vladimir P. Fedin、Ya-Guang Sun
DOI:10.1039/c8ce01242c
日期:——
Eight homochiral lanthanidecoordination polymers, namely [Ln2L3(H2O)2]n·4nH2O [Ln = Sm (1); Eu (2); Gd (3); Tb (4); Dy (5); Ho (6); Er (7); Yb (8)], based on an achiral rigid ligand, 5-[(pyridin-4-ylmethyl)amino]-isophthalic acid (H2L), have been hydrothermally prepared and characterized by single X-ray diffraction, elemental analysis, infrared spectroscopy, thermogravimetric analysis, powder X-ray
八个同手性镧系配位聚合物,即[Ln 2 L 3(H 2 O)2 ] n ·4 n H 2 O [Ln = Sm(1); ((2); d(3); b(4); Dy(5); 何(6); ((7); Yb(8)],基于非手性刚性配体,5-[(吡啶-4-基甲基)氨基]-间苯二甲酸(H 2L)已经水热制备,并通过单X射线衍射,元素分析,红外光谱,热重分析,粉末X射线衍射和圆二色光谱表征。化合物1-8的特征是带有三链螺旋链的三维骨架,具有Schläfli符号4 5 ·6·10 4 } 4 5 ·6}的拓扑结构。固态圆二色性(CD)光谱显示结晶过程中发生自发手性对称性破坏,并且手性的起源可能是螺旋性。此外,已经研究了发光和二次谐波产生(SHG)活性。化合物5显示出SHG活性。化合物1,2和4显示的特征发光从三价镧系元素所产生。
A Porous Coordination Polymer Exhibiting Reversible Single-Crystal to Single-Crystal Substitution Reactions at Mn(II) Centers by Nitrile Guest Molecules
作者:Madhab C. Das、Parimal K. Bharadwaj
DOI:10.1021/ja9006035
日期:2009.8.12
The porous coordination polymer [Mn(L)(H2O)](H2O)(1.5)(DMF)}(n) (1) containing a water molecule coordinated at the apical position of each distorted octahedral Mn(II) center has been synthesized using the solvothermal technique by reacting Mn(NO3)(2)-4H(2)O with a new flexible ligand (LH2) having isophthalic fragment and pyridine donors at the two ends. The coordinated water molecule could be substituted by nitrile guest molecules such as acetonitrile, acrylonitrile, allylnitrile, and crotononitrile (affording compounds 2-5, respectively) without loss of crystallinity. Interestingly, compound 1 selectively captures cis-crotononitrile into its cavity from a mixture of cis and trans isomers. Hence, the cis isomer can be separated from the trans isomer. In each case, 1.5 lattice water molecules and a dimethylformamide (DMF) molecule are also simultaneously replaced by certain numbers of these guest molecules. When these first-gene ration compounds 2-5 are dipped in DMF at room temperature with the lid of the vial open to the atmosphere, the mother crystal 1 is regenerated in each case. Thus, all of these substitution reactions are completely reversible. Also, the first-generation compounds 2-5 can be interconverted among one another by dipping them in appropriate nitrile guests. All of these phenomena could be observed in single-crystal to single-crystal fashion.
Metal–Organic Frameworks with Pyridyl-Based Isophthalic Acid and Their Catalytic Applications in Microwave Assisted Peroxidative Oxidation of Alcohols and Henry Reaction
作者:Anirban Karmakar、Luísa M. D. R. S. Martins、Susanta Hazra、M. Fátima C. Guedes da Silva、Armando J. L. Pombeiro
DOI:10.1021/acs.cgd.5b01178
日期:2016.4.6
building unit. These frameworks act as heterogeneous polymeric solid catalysts (the most effective one being the copper MOF 1) for solvent-free microwave assisted peroxidative oxidation of primary and secondary alcohols. They also effectively catalyze the nitroaldol (Henry) reaction of different aldehydes with nitroalkanes in water. These MOF-based heterogeneouscatalysts can be easily recovered and reused
AbstractTwo reduced Schiff bases, namely 5-[(2-hydroxybenzyl)amino]isophthalic acid (1) and 5-[(pyridin-4-ylmethyl)amino]isophthalic acid (2), were synthesized in two-step method using 5-aminoisophthalic acid as the starting material, and were characterized by single-crystal X-ray diffraction, elemental analysis, infrared, 1H NMR, mass, absorption and fluorescence spectra. Both 1 and 2 crystallize in