排序方式: 共有114条查询结果,搜索用时 15 毫秒
81.
采用表面引发原子转移自由基聚合(SI-ATRP)方法将丙烯腈(AN) 接枝到氯甲基化聚苯乙烯树脂(PS-CH2Cl) 表面, 再与叠氮化钠进行3+2环加成反应, 制备了一种聚乙烯四唑型螯合树脂(PVT-g-PS). 用红外光谱和元素分析对PVT-g-PS树脂进行了表征, 考察了该树脂对Pb(Ⅱ), Ni(Ⅱ)和Cd(Ⅱ)的吸附性能. 在一定聚合时间范围内, 丙烯腈接枝率与SI-ATRP时间呈线性关系, 树脂表面四唑含量及树脂对金属离子的吸附容量随丙烯腈接枝率增大而增大, 说明丙烯腈在树脂表面聚合为活性可控聚合, 树脂表面功能团含量和树脂吸附容量可以用聚合时间调控. 通过分析树脂吸附容量与溶液pH值的关系、 吸附等温线和吸附动力学, 证明3种金属离子的吸附主要是基于配位作用的化学吸附. 当SI-ATRP时间为10 h时, 树脂对Pb(Ⅱ), Ni(Ⅱ)和Cd(Ⅱ)吸附容量高达1.57, 1.68和1.92 mmol/g. 经过10次吸附-解吸循环实验, 树脂的吸附容量无显著变化, 表明新型树脂具有较高的吸附量和良好的重复使用性. 相似文献
82.
Based on the parent tetrazole 2N-oxide, six series of novel carbon-linked ditetrazole 2N-oxides with different energetic substituent groups (-NH2, -N3, -NO2, NF2, -NHNO2) and energetic bridge groups (-CH2-, -CH2-CH2-, -NH-, -N=N-, -NH-NH-) were designed. The overall performance and the effects of different energetic substituent groups and energetic bridge groups on the performance were investigated by density functional theory and electrostatic potential methods. The results showed that most of designed compounds have oxygen balance around zero, high heats of formation, high density, high energy, and acceptable sensitivity, indicating that tetrazole N-oxide is a useful parent energetic compound employed for obtaining high energy compounds, even only combined with some very common energetic substituent groups and bridge groups. Comprehensively considering the effects on energy and sensitivity, the -NO2, -NF2, -NH-and -NH-NH-are appropriate substituent groups for combining tetrozale N-oxide to design new energetic compounds, while -NH2, -N3, -CH2-CH2-, and -N=N-are inappropriate. 相似文献
83.
Bo‐Wen Hu Wen‐Qi Zhu Wei‐Wei Shi Peng Chen Quan‐Wen Li Ge‐Ping Yin 《无机化学与普通化学杂志》2019,645(16):1062-1066
A series of heterometallic NiII/CoII coordination polymers with 2D networks were synthesized by tetrazole‐1‐acetate ligands and structurally characterized. With increasing concentration of cobalt(II), another different connectivity patterns have been observed. The influence of cobalt(II) is not only on the crystallization, but also on the variation of magnetic properties. 相似文献
84.
Chong Qin Yijin Su Tao Shen Xiaodong Shi Ning Jiao 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2016,128(1):358-362
A gold‐catalyzed nitrogenation of alkynes for the synthesis of carbamides and amino tetrazoles through C C and CC bond cleavages is described. A diverse set of functionalized carbamide and amino tetrazole derivatives were selectively constructed under mild conditions. The chemoselectivity can be easily switched by the selection of the acid additives. The reaction is characterized by its broad substrate scope, direct construction of high value products, easy operation under air, and mild conditions at room temperature. This chemistry provides a way to transform alkynes by splitting the substrate into three parts. 相似文献
85.
《Journal of Coordination Chemistry》2012,65(11):1253-1260
The solid-state structure of the highly insoluble silver complex 1-phenyl-1H-tetrazole-5-thiol (AgPMT), without solubilizing ligands, has been successfully resolved. The crystal structure of {[(AgPMT)4?·?0.5THF]} n consists of polymeric repeating units of asymmetrically constructed AgPMT dimers. The asymmetric dimers are based on S–Ag–N and N–Ag–N links, and reveal the routes of connectivity possible with this multidentate ligand. This is one of the few linear, one-dimensional silver-based polymers. 相似文献
86.
Federico MeddaChristopher Hulme 《Tetrahedron letters》2012,53(42):5593-5596
This Letter describes novel methodology for the rapid assembly of new and biologically appealing 1,5-substituted tetrazole-hydantoins and thiohydantoins. The product of a TMSN3-Ugi multi-component reaction is treated with an excess of isocyanate or isothiocyanate to generate the final scaffold in moderate to good yields. The applicability of this solution phase methodology to the preparation of a small collection of compounds is discussed. 相似文献
87.
Shinya Harusawa Hiroki YoneyamaDaiki Fujisue Masayoshi NishiuraMihoyo Fujitake Yoshihide UsamiZheng-yun Zhao Scott A. McPheeTimothy J. Wilson David M.J. Lilley 《Tetrahedron letters》2012,53(44):5891-5894
Novel C5-linked C0- and C2-tetrazole ribonucleoside phosphoramidites were designed and synthesized via tetrazole C-nucleosides. Pivaloyloxymethyl (POM) and methyl-substituted POM (MePOM) groups were introduced as N-protecting groups in the tetrazole ring that can be readily removed under mild basic conditions. The phosphoramidites were successfully incorporated into the VS ribozyme substrate and hence providing a chemogenetic approach to determine which nucleobases of ribozymes function as the acid or base, in the studies of ribozyme general acid and base catalysis. 相似文献
88.
B3LYP/6-31G(d), B3LYP/6-311++G(d,p), and CBS-QB3 calculations on the effect of CuCl on the azido/tetrazole isomerism have been performed. The cases of 2-azidopyridine and 2-azido-1H-imidazole have been selected as examples of heteroaromatic six- and five-membered rings. All minima and transition states have been characterized. 相似文献
89.
The one-pot regioselective preparation of 5-aryl/alkyl-2-vinyl-2H-tetrazoles from 5-substituted tetrazoles via a very simple procedure using 1,2-dibromoethane and triethylamine without the need of any catalyst is described. The mechanism of this reaction is also discussed. 相似文献
90.
Laser Raman evidence is presented to support the existence of reversible interconversion of 5-aminotetrazole-H2O and 5-iminotetrazole·H2O in the solid state. 相似文献