共查询到20条相似文献,搜索用时 46 毫秒
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一氧化碳高效吸附剂CuCl/分子筛 总被引:17,自引:2,他引:15
利用自发单层分散原理,将CuCl分散在载体表面制备高效的CO吸附剂,将CuCl与γ-Al2O3,4A,13X,NaY,CuY分子筛等高比表在载体混合,在350℃焙烧数小时,XRD和EXAFS研究证明CuCl可在载体表面达到原子水平的分散由于Cu^+可与CO生成配位键。由此可制得对CO有高吸附容量和选择性的吸附剂,其中CuCl/NaY和CuCl/Cu^+Y吸附剂的吸附容量在20℃,CO分压为60kP 相似文献
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试验几种无机氯化物对镍-4-[(5-氯-2-吡啶)偶氮]-1,3-二氨基苯(Ni-5-Cl-PADAB)显色反应的影响,无机盐对该显色体系有较强的增敏作用,且依NaCl>KCl~LiCl>MgCl2的顺序减弱;此外无机盐还能提高该显色反应的选择性及稳定性。从引入无机氯化物前后显色剂及配合物吸收光谱的变化,PKa3及配合物稳定常数的改变等方面探讨了无机氯化物对显色反应增敏作用的机理,并将Ni-5-C 相似文献
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超微NaY分子筛的合成(Ⅰ)--添加轻稀土离子的影响 总被引:11,自引:0,他引:11
导向剂的陈化时间和反应胶的晶化温度可以影响NaY分子筛的晶化行为。随导向剂陈化时间的增加,NaY分子筛的晶化速度加快晶粒尺寸减少;随晶化温度的升高,NaY分子筛的晶化速度加快,但晶粒尺寸增加。而向合成体系中添加轻稀土离子(Ln^3+)对NaY分子筛的晶化行为影响更为明显。与未添加稀土离子时相比较,在一定的稀土离子添加量范围内〔n(Ln^3+)/n(Al^3+)〈0.2〕,NaY分子筛的晶化速度明显 相似文献
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利用DTA研究了ErCl_3CaCl_2LiCl三元体系相图。发现该相图有对应于ErCl_3、CaCl_2、LiCl和Li_3ErCl_6的4个液相面,5条二次结晶线,一个三元低共熔点E(58.5%ErCl_3,23.7%CaCl_2,17.8%LiCl,397℃),一个三元转熔点P(52.5%ErCl_3,27.2%CaCl_2,20.3%LiCl,428℃)。相应的4相平衡反应为:L=ErCl_3+Li_3ErCl_6+CaCl_2;L+LiCl=Li_3ErCl_6+CaCl_2. 相似文献
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Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction
Laurent Gavara Thomas Boisse Jean-Pierre Hénichart Adam Daïch Philippe Gautret 《Tetrahedron》2010,66(38):7544-5571
In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments. 相似文献
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KMnO4-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields. 相似文献
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N. A. Nedolya 《Chemistry of Heterocyclic Compounds》2008,44(10):1165-1219
The review contains a concise historical account and information on the most significant researches undertaken by the staff
at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry
of Heterocyclic Compounds.
Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee.
Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008. 相似文献
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Uroš Grošelj Mojca Žorž Amalija Golobič Branko Stanovnik Jurij Svete 《Tetrahedron》2013,69(52):11092-11108
A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives. 相似文献
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Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields. 相似文献
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The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp3)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp2)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp2)?H and aliphatic 1,5- and 1,6-C(sp3)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp3)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp2)?H insertion. 相似文献
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Rebecca J. Burton Mandy L. CrowtherNeal J. Fazakerley Shaun M. FilleryBarry M. Hayter Jason G. KettleCaroline A. McMillan Paula PerkinsPeter Robins Peter M. SmithEmma J. Williams Gail L. Wrigley 《Tetrahedron letters》2013
The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines. 相似文献
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An efficient approach to the synthesis of highly congested di, penta and hexacyclic pyrazoles as well as imidazole fragment containing novel heterocyclic molecule has been developed through a carbanion induced transformation of suitably functionalized 2H-pyran-2-ones, benzo[h]chromene and thiochromeno[4,3-b]pyrans. Due to the presence of fluorescence, we report their prime application metal sensor as off/on switching in ferric ions. 相似文献
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N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%). 相似文献