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1.
以十六烷基三甲基省化铵(CTAB)作模板剂,研究了水热体系中孔MCM-41分子筛的合成条件。在H2O/Si介于12-100,Si/Al介于10-∞,CTAB/Si介于0.08-0.2时,可以合成出MCM-41分子筛,在国入煤油等混合烃的合成体系中,可以合成出孔径大于4nmdisplay structure  相似文献   

2.
在凝胶体系NaX(F、Cl、Br)Na2OAl2O3SiO2CTAB(十六烷基三甲基溴化铵)H2O中,研究了水热合成中孔MCM41的合成条件。实验证明,在398K下晶化8~16d,NaX/SiO2介于0.01~0.05时,均可合成出MCM41分子筛;NaF的加入,可以加快MCM41分子筛的晶化速度;NaBr的加入,对形成MCM41分子筛有阻碍作用。采用XRD、SEM、TGDTA和N2吸附对合成样品加以表征,证明合成样品具有介孔分子筛特性。  相似文献   

3.
窦涛  钟炳 《燃料化学学报》1998,26(2):175-179
本文采用表面活性剂十六烷基三甲基溴经铵,在OH-SiO2-C16TABr-H2O体系中分别和利用室温,水热及干粉法进行了纯硅MCM-41中孔分子筛的合成,考察了阳离子Na^+,K^+对MCM-41合成及稳定性的影响。  相似文献   

4.
本文采用表面活性剂十六烷基三甲基溴化铵(C16TABr,以下为1631),在(Na,K)OHSiO2C16TABrH2O体系中分别利用室温、水热及干粉法进行了纯硅MCM41中孔分子筛的合成,考察了阳离子Na+、K+对MCM41合成及稳定性的影响。通过XRD对结晶度的测定,发现NaMCM41的晶化速率明显高于KMCM41,而热稳定性和水热稳定性较差,且a0值小于后者。同时发现,就合成方法而言,室温法得到的产物具有很高的结晶度,利用水热法合成的样品的热稳定性明显较高,而干法得到的分子筛产品具有优良的水热稳定性。  相似文献   

5.
EFFECT OF CRYSTALLIZATION TEMPERATURE ON MCM-41 SYNTHESIS   总被引:1,自引:0,他引:1       下载免费PDF全文
在Na2OSiO2CTABH2O四元水热体系中系统地考察了晶化温度对中孔MCM41分子筛合成及其骨架结构的影响。实验结果表明,提高晶化温度虽然能明显加快晶化速率,缩短晶化时间,但同时样品的结晶度和中孔骨架结构的有序度却被迅速破坏。这些特点与传统沸石的合成过程完全不同,其原因主要是合成MCM4l时所用的模板剂及其在合成中所起的模板作用与传统沸石完全不同。相对低的晶化温度(如100℃)有利于高质量和高热稳定性的中孔MCM4l分子筛的合成。  相似文献   

6.
在蒸气相中合成中孔分子筛MCM—41及其孔结构参数的表征   总被引:6,自引:0,他引:6  
在水蒸气中,由含表面活性剂十六烷基三甲基溴化铵的无定形凝胶合成出Si-MCM-41和Al-Si-MCM-41分子筛纯相,研究了它们的合成条件。  相似文献   

7.
新型洗涤剂用沸石MAP的合成及其性能表征   总被引:4,自引:0,他引:4  
在SiO_2-Al_2O_3-Na_2O-H_2O体系中,采用加入晶种的方法水热合成出新型洗涤剂用沸石-MAP。其硅铝比(Si/Al)在 1.07-1.13之间,平均晶粒直径小于0.4μm,钙离子交换容量为290~313 mgCaCO_3/g(干沸石),非离子表面活性剂的吸附量在 83~ 100g oil/100g(沸石)之间。本文着重考察了影响合成 MAP沸石的因素,确定了MAP沸石会成的最佳范围,并对其物理化学性质进行了表征。  相似文献   

8.
中孔MCM—41分子筛在微孔沸石ZSM—5上附晶生长的研究   总被引:15,自引:2,他引:15  
首次在微孔沸石ZSM5表面进行了MCM41分子筛的附晶生长,并首次提出中孔材料MCM41分子筛静电组配理论的新形式(XS+I);同时利用XRD、TEM、BET等测试手段表征了合成样品,并讨论了微孔沸石表面附晶生长中孔分子筛MCM41的合成化学,考察了F离子效应、pH值及表面活性剂CTAB(十六烷基三甲基溴化铵)的影响。  相似文献   

9.
1,2-二(三甲硅基环戊二烯基)四甲基二硅烷与Fe(CO)_5在二甲苯中于105~110℃反应除分离到少量标题化合物(Me_2SiSiMe_2)[η-(3-Me_3SiC_5H_3Fe(CO)]_2(μ-CO)_2(5)外,主要是生成了脱Me_3Si基的产物(Me_2SiSiMe_2)[η-C_5H_4Fe(CO)]_2(μ-CO)_2(1)及1的热重排异构体[Me_2SiC5H4-Fe(CO)_2]_2(2).将5的二甲苯溶液加热回流18h,则转化为其异构体[Me_2Si(Me_3SiC_5H_3)Fe(CO)_2]_2(6).脱硅基发生在由相应反应物制备5的过程中。且脱硅基是与反应物中(Me_2SiSiMe_2)桥的存在有关.5的晶体结构经X射线衍射测定属单斜晶系,P2_1/m空间群,晶体学数据:a=0.6780(1)nm,b=2.2303(9)nm,c=0.9988(1)nn,;β=98.96(1)°,V=1.4960nm~3.Z=2,D_c=1.36g/cm~3.  相似文献   

10.
水热法合成了具有超大孔MCM-41分子筛结构的含Pe和V-Ti分子筛,通过XRD、骨架IR、ESR、 ̄(29)SiMASNMR、紫外漫反射等测试表征证实,Fe原子在FeMCM-41分子筛骨架上,V和Ti同时进入V-TiMCM-41分子筛骨架。FeMCM-41的骨架红外谱除Fe分子筛的特征吸收峰660cm ̄(-1)外,还显示960cm ̄(-1)峰,ESR谱出现高对称八面体环境Fe(Ⅲ)信号(g=2.0)和扭曲四面体环境Fe(Ⅲ)信号(g=4.2),而V-TiMCM-41的骨架红外960cm ̄(-1)峰强度分别随分子筛中钛或钒的含量线性增强。约在g=1.98处出现的超精细结构ESR信号表明V以分散的不流动的V ̄(4+)形式存在,化学分析结果表明骨架上Ti和V原子相互间不排斥。  相似文献   

11.
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   

12.
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   

13.
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   

14.
An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y1 and Y2. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.  相似文献   

15.
In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates.  相似文献   

16.
Synthesis of substituted pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles from the Morita-Baylis-Hillman derivatives of acrylates via saponification followed by Curtius reaction is described.  相似文献   

17.
用正丁胺作为碳源,采用射频辉光放电制备碳膜,选用激光染料R6G和聚乙二醇混合液作为蒸气源,采用单源热蒸发,在蒸发室与染料同时沉积得到混合膜,用拉曼光谱和红外光谱分析了碳膜的结构和键合方式,分析表明:碳膜中存在胺基团和氢原子.混合膜的荧光谱测量结果表明,认为正丁胺对染料荧光谱的影响是因为胺基和氢原子的存在.  相似文献   

18.
19.
A series of 20 CuAIAC reactions between eight 4-acylamino substituted pyrazolidine-3-one-1-azomethine imines and four terminal ynones were performed using Cu0 as catalyst. The corresponding fluorescent cycloadducts were obtained in very high yields upon simple workup. Thus, Cu-metal turned out to be a better catalyst than CuI in terms of yield and ease of isolation. Availability of azomethine imines, mild reaction conditions, and simple workup enable a “click” access to libraries of densely substituted 2,3-dihydro-1H,5H-pyrazolo[1,2-a]pyrazol-1-ones. Reactivity of differently substituted dipoles was evaluated experimentally and by quantum chemical methods (DFT).  相似文献   

20.
(E)-4-(Fullerenopyrrolidin-1-yl)-3-methylbut-2-enoic acid and its corresponding succinimidyl ester, readily obtained through Prato-type modification of C60, were used for the selective N-acylation of polyamines. The thus obtained conjugates were evaluated for their antioxidative and anti-inflammatory activity and their cytotoxicity was determined. Members of this family of compounds showed interesting anti-lipid peroxidation, anti-lipoxygenase and anti-inflammatory activity and comparable cytocompatibility to spermidine.  相似文献   

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