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101.
Jessica L. Klinkenberg Prof. John F. Hartwig 《Angewandte Chemie (International ed. in English)》2011,50(1):86-95
Until recently, ammonia had rarely succumbed to catalytic transformations with homogeneous catalysts, and the development of such reactions that are selective for the formation of single products under mild conditions has encountered numerous challenges. However, recently developed catalysts have allowed several classes of reactions to create products with nitrogen‐containing functional groups from ammonia. These reactions include hydroaminomethylation, reductive amination, alkylation, allylic substitution, hydroamination, and cross‐coupling. This Minireview describes examples of these processes and the factors that control catalyst activity and selectivity. 相似文献
102.
Abstract The elaboration of the theoretical experimental model of the absorption process under a pressure of 30 MPa and moderate temperatures included the experimental research of methan and argon absorption from the five-component mixture H2-N2-CH4-Ar-NH3 by liquid ammonia on a pilot plant and carrying out the computerized research of process statics. 相似文献
103.
104.
Guorong Duan Junwu Zhu Chun Kan Xujie Yang Lude Lu Xin Wang 《Reaction Kinetics and Catalysis Letters》2007,92(2):247-256
For the first time, novel structural nanosized Y2O3 powders were successfully synthesized by the n-butanol soft-template method. X-ray diffraction, transmission electron microscopy, scanning electron microscopy and Raman
spectroscopy were used to characterize the products. The results indicate that these products (calcined at 700°C) were comprised
of many Y2O3 nanomembranes, and the nanomembranes could change into nanorods when calcined at 1000°C. Interestingly, differential thermal
analysis studies suggested that the nanosized Y2O3 crystals had intense catalytic activity on the thermal decomposition of ammonium perchlorate. 相似文献
105.
Zheng DUAN Zhong Xian LI Yang Jie WU 《中国化学快报》2006,17(7):880-882
Ferrocenylcyanide is a valuable precursor for preparation of nitrogen-containing ferrocenyl ligands. Originally, ferrocenylcyanide was prepared from ferrocenecarboxy- aldehyde by multi-steps transformations, at evaluated temperature. Very recently, a modi… 相似文献
106.
氨及其氟取代物与氟化氢形成氢键络合物的系列理论研究 总被引:1,自引:0,他引:1
采用ab initio方法,在6-31G水平上,对NH3…NF、NH2F…HF、NF3…HF4种氢键络合物的5组构型进行了一系列能量梯度法的构型优化和能量计算,取得到关于这些分子络合物的结构特征,氢键键能与键级,单体电荷迁移量等信息,分析,比较得出了在每种构型下各体系的重要物理量随氟基数的递变规律,并探讨了氟基的诱导效应对上述体系氢键作用的影响。 相似文献
107.
P. W. Schenk 《Angewandte Chemie (International ed. in English)》1966,5(6):554-557
An apparatus for titrations in liquid ammonia is described. The titrations can be carried out in the absence of air, and the utility of the apparatus is demonstrated for a number of conductometric and potentiometric titrations. 相似文献
108.
Summary A simple and reliable method for routine measurement of ammonia in ambient air is described. It is based on the collection of ammonia on H3PO3-coated annular denuders and its subsequent derivatization withm-toluoyl chloride (MTC) in alkaline acetonitrile. The resultingm-toluamide is determined by reversed phase HPLC with UV detection at 230 nm. The limit of dotection is about 0.3g m–3 for NH3 in air samples collected at 151 min–1 for one hour. 相似文献
109.
Awatef Hattab Zoubeida Dhaouadi Alhadji Malloum Jean Jules Fifen Souad Lahmar Nino Russo Emilia Sicilia 《Journal of computational chemistry》2019,40(18):1707-1717
The possible isomers of [Mg(NH3)n = 1 − 10]+ clusters have been investigated using both M06-2X/6-31++G(d,p) and MP2/6-31++G(d,p) levels of theory. The isomeric distribution for each n size has been studied as a function of temperatures ranging from 25 to 400 K. To the best of our knowledge, for clusters size n > 6, this is the first theoretical study available in the literature. From the calculated values in the considered clusters and using a fitting procedure, we have evaluated the binding energies (−14.0 kcal/mol), clustering energies (−10.1 kcal/mol), clustering free energies (−2.8 kcal/mol), and clustering enthalpies (−10.3 kcal/mol). On the basis of our structural and infrared (IR) spectroscopy outcomes, we find that the first solvation shell can hold up to six ammonia molecules. © 2019 Wiley Periodicals, Inc. 相似文献
110.
利用相分离技术制备了非晶三维贯穿大孔氧化铝初始材料,然后通过氨水水热改性处理,使其大孔形态发生了显著改变,孔壁边缘生长有尺寸为50-300 nm的片状聚集体,大孔尺寸由430 nm下降到250 nm,但仍然保持蠕虫状三维贯穿且空间分布均匀的特性。改性后的氧化铝材料经550℃焙烧转化为高结晶度γ氧化铝,比表面积达到331 m2/g,具有8.9 nm及250 nm两种集中的孔径分布,L酸度及抗压强度均有所提高。研究表明,无定形水合羟基铝离子聚合物与氨水发生再水合反应生成薄水铝石中间物,因此,可在较低的焙烧温度下转晶为γ态;大孔孔壁边缘的AlOOH晶粒受NH4+模板诱导作用从里向外重排形成片状聚集体,从而改变了大孔的形态。 相似文献