2632-99-7Relevant articles and documents
A “Thermodynamically Stable” 2D Nickel Metal–Organic Framework over a Wide pH Range with Scalable Preparation for Efficient C2s over C1 Hydrocarbon Separations
Sahoo, Rupam,Chand, Santanu,Mondal, Manas,Pal, Arun,Pal, Shyam Chand,Rana, Malay Kumar,Das, Madhab C.
, p. 12624 - 12631 (2020)
The design and construction of “thermodynamically stable” metal–organic frameworks (MOFs) that can survive in liquid water, boiling water, and acidic/basic solutions over a wide pH range is highly desirable for many practical applications, especially adsorption-based gas separations with obvious scalable preparations. Herein, a new thermodynamically stable Ni MOF, {[Ni(L)(1,4-NDC)(H2O)2]}n (IITKGP-20; L=4,4′-azobispyridine; 1,4-NDC=1,4-naphthalene dicarboxylic acid; IITKGP stands for the Indian Institute of Technology Kharagpur), has been designed that displays moderate porosity with a BET surface area of 218 m2 g?1 and micropores along the [10?1] direction. As an alternative to a cost-intensive, cryogenic, high-pressure distillation process for the separation of hydrocarbons, MOFs have recently shown promise for such separations. Thus, towards an application standpoint, this MOF exhibits a higher uptake of C2 hydrocarbons over that of C1 hydrocarbon under ambient conditions, with one of the highest selectivities based on the ideal adsorbed solution theory (IAST) method. A combination of two strategies (the presence of stronger metal–N coordination of the spacer and the hydrophobicity of the aromatic moiety of the organic ligand) possibly makes the framework highly robust, even stable in boiling water and over a wide range of pH 2–10, and represents the first example of a thermodynamically stable MOF displaying a 2D structural network. Moreover, this material is easily scalable by heating the reaction mixture at reflux overnight. Because such separations are performed in the presence of water vapor and acidic gases, there is a great need to explore thermodynamically stable MOFs that retain not only structural integrity, but also the porosity of the frameworks.
Synthesis and characterization of four novel manganese(II) chains formed by 4,4′-azobis(pyridine) and benzoate or nitrobenzoates: Stabilization of unusual ladder structures
Kar, Paramita,Drew, Michael G.B.,Gómez-García, Carlos J.,Ghosh, Ashutosh
, p. 229 - 239 (2013)
Four new manganese(II) coordination polymers: [Mn(4,4′-azpy)(C 6H5COO)2](4,4′-azpy)0.5 (1), [Mn(4,4′-azpy)(p-(NO2)C6H4COO) 2] (2), [Mn(4,4′-azpy)(m-(NO2)C6H 4COO)2] (3) and [Mn(4,4′-azpy)(o-(NO 2)C6H4COO)2(H2O) 2] (4), where 4,4′-azpy = 4,4′-azobis(pyridine), have been synthesized by self-assembly of MnX2 (X = benzoate, p-, m-, or o-nitrobenzoates) together with 4,4′-azpy. All four complexes were characterized by elemental analyses, IR spectroscopy, thermal analyses, single-crystal X-ray diffraction analyses and variable-temperature magnetic measurements. The structural analyses reveal that complexes 1, 2 and 3 feature a 1D molecular ladder formed by syn-syn (complex 1) or syn-anti (complexes 2 and 3) carboxylate-bridged dimeric Mn(II) units which are joined together by 4,4′-azpy ligands. In complex 1, these ladders assemble with the help of π-π and C-H?π interactions to form a nanoporous framework that incorporates non coordinated 4,4′-azpy molecules by exploiting host-guest C-H?π and hydrogen bonding interactions. Complex 2 presents a 3D supramolecular framework by π-π and CH?π interactions, whereas, complex 3 having a similar ladder structure to 1 and 2, forms a 2D grid through π-π interactions. On the other hand, complex 4 is a 4,4′-azpy bridged fish-bone chain of carboxylate-coordinated mononuclear manganese(II) units, which are linked together by strong hydrogen bonds to form a 2D structure. Variable-temperature (2-300 K) magnetic susceptibility measurements show the presence of weak antiferromagnetic interactions within the discrete Mn-(OCO)2-Mn dimers for complexes 1, 2 and 3 that have been fitted with a S = 5/2 dimer model (J = -0.8, -0.5 and -0.4 cm-1 respectively). The magnetic data of complex 4 can be reproduced with a S = 5/2 monomer model including a Zero Field Splitting (|D| = 1.7 cm-1).
4-Pyridylnitrene and 2-pyrazinylcarbene
Wentrup, Curt,Reisinger, Ales,Kvaskoff, David
, p. 754 - 760 (2013)
Both flash vacuum thermolysis (FVT) and matrix photolysis generate 2-diazomethylpyrazine (22) from 1,2,3-triazolo[1,5- a]pyrazine (24). FVT of 4-azidopyridine (18) as well as of 24 or 2-(5-tetrazolyl)pyrazine (23) affords the products expected from the nitrene, i.e., 4,4'-azopyridine and 2- and 3-cyanopyrroles. Matrix photolyses of both 18 and 24 result in ring expansion of 4-pyridylnitrene/2-pyrazinylcarbene to 1,5-diazacyclohepta-1,2,4,6-tetraene (20). Further photolysis causes ring opening to the ketenimine 27.
Electrochemical dehydrogenation of hydrazines to azo compounds
Du, Ke-Si,Huang, Jing-Mei
supporting information, p. 1680 - 1685 (2019/04/08)
A strategy for the electrochemical dehydrogenation of hydrazine compounds is disclosed under ambient conditions. This protocol proceeded smoothly in ethanol by employing electrons as clean oxidants. Its synthetic value is well demonstrated by the highly efficient synthesis of symmetric and unsymmetric azo compounds. It is an environmentally friendly transformation and the present protocol was effective on a large scale.
