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1.
柱撑水滑石类层柱状阴离子粘土是一类新型层柱材料,由于其二维孔道结构的可调变性及潜在的择形催化性能,已引起人们的重视[1-3].迄今,人们已合成了包括无机和有机阴离子,同多和杂多阴离子(Polyoxometalates,简称POMs)以及配合物阴离子在内的多种柱撑水滑石,其中同多和  相似文献   

2.
钛层柱粘土的合成:Ⅱ.硫酸钛作钛源   总被引:3,自引:0,他引:3  
以硫酸钛作钛源得到的钛柱化剂与Na型蒙脱石交换合成了钛层柱粘土(Ti-PILC)。详细考察了交换时温度、酸浓度、Ti(Ⅳ)浓度以及Ti(Ⅳ)与粘土比等对柱化粘土层结构的影响。结果表明,提高反应温度或降低酸浓度都能导致层离Ti-PILC的生成,产物的大部分比表面积及也容由层离产生的大孔(D>1.0nm)所贡献。Ti(Ⅳ)水解生成尺寸不等的氧化钛胶粒,带正电荷的胶粒插入粘土层间是产生层离的主要原因。  相似文献   

3.
钛层柱粘土的合成:I.四氯化钛作钛源   总被引:17,自引:0,他引:17  
由TiCl4/HCl配制的含钛柱化剂与粘土进行阳离子交换后得到大孔钛层柱粘土(Ti-PILC),详细研究了各种合成条件,诸如Ti(Ⅳ)及HCl浓度,柱化剂老化时间,粘土初始浓度,交换温度及配料比等对层柱粘土的大孔及比表面的影响。优化条件合成的Ti-PILC存在的两种晶面间距(d001),其中之一(2.56nm)大孔结构。Ti-PILC比表面积为328m^2/g,500℃焙烧后d001保持2.32n  相似文献   

4.
为了改善氧化钛层柱蒙脱石的结构性能,以长链聚合物-端氨基聚甲基环氧乙烷(PPO-D-2000)为结构调节剂,调控合成了聚合物-氧化钛层柱蒙脱石材料。采用X射线粉末衍射、红外、拉曼光谱、TG/DSC、TEM和BET等手段进行了结构表征。结果表明,相比于小分子量表面活性剂而言,长链聚合物不仅能显著提高氧化钛层柱蒙脱石中的二氧化钛含量,而且比表面积比单独氧化钛柱撑蒙脱石增加了约13%,达到241.52m2/g,尤其是孔径、孔体积等孔道结构参数增加一倍左右。将合成的柱撑蒙脱石材料应用于对水中甲基橙的吸附和光催化性能研究表明,聚合物的调控作用能提高氧化钛层柱蒙脱石的吸附能力,光催化效率也有所改善。因此,聚合物对优化无机层柱粘土材料结构、改善吸附和催化性能具有良好的调控作用,为发展环境催化材料提供了新的途径。  相似文献   

5.
采用水热合成及离子交换法将Keggin结构三铁九钨镓酸盐杂多阴离子GaW9Fe3(H2O)3嵌入Zn2Al型阴离子粘土层间,得到了新型层柱状微孔材料Zn2Al-GaW9Fe3.用元素分析、XRD、IR、XPS等手段对产物的组成和结构进行了表征.结果表明,杂多阴离子嵌入Zn2Al型阴离子粘土层间,使柱撑杂多阴离子粘土具有1.0nm的通道高度.  相似文献   

6.
介孔硅层柱蒙脱石材料合成的新方法与表征   总被引:14,自引:0,他引:14  
利用十六烷基三甲基溴化铵(CTAB)将天然钠基蒙脱石改性成有机蒙脱石,以十二烷胺为模板剂,正硅酸乙酯为层柱前驱体,在室温下合成了新型介孔硅层柱蒙脱石材料.用XRD,TG,FTIR以及N2等温吸附-脱附等技术对产物进行了表征.结果表明,合成材料具有大通道(净层间距为2.75nm)、介孔孔径且孔分布窄(平均孔径为2.17nm)、比表面积高(SBET=821.6m2/g)、热稳定性高(大于800℃)等特征.同时,通过改变中性胺的链长,研究了孔结构的调变规律,分析了材料的成孔机理和热稳定性提高的原因.  相似文献   

7.
柱撑化合物Zn2Al-PW11Z的结构模型及酯化活性   总被引:1,自引:1,他引:1  
杂多化合物是性能优异的酸型和氧化型或双功能催化剂[1-4],而通式为的阴离子粘土通常具有减催化或还原催化性能[5,6].因此,从在分子及原子水平上设计催化剂,调控催化性能观点出发,人们期望将体积较大的杂多阴离子嵌入阴离子粘土层间,合成大层间距的新型柱撑微孔材料.1988年Pinnavaia等人[7]首次报导了Zn2Al-V10O28是具有2.0nm孔径分布的中微孔材料.最近,笔者将单取代型Keggin结构杂多阴离子GeW11O39Z(H2O)6-(其中Z=Ni2 和Cu2 )和缺位Keggin结构的GeW11O嵌入Zn2Al-NO3层间,合成了通道高度为0.9nm的新型柱撑…  相似文献   

8.
由TiCl4/HCl配制的含钛柱化剂与粘土进行阳离子交换后得到大孔钛层柱粘土(Ti-PILC),详细研究了各种合成条件,诸如Ti(Ⅳ)及HCl浓度,柱化剂老化时间,粘土初始浓度,交换温度及配料比等对层柱粘土的大孔及比表面积的影响.优化条件合成的Ti-PILC存在两种晶面间距(d001),其中之一(2.56nm)对应大孔结构.Ti-PILC比表面积为328m2/g,500℃焙烧后d001保持2.32nm,650℃焙烧后比表面积仍达301.4m2/g.Ti-PILC的大孔结构主要取决于交换时混合液中Ti(Ⅳ)和HCl浓度,并与柱化剂老化时间、交换温度等因素有关;与原柱化剂中Ti(Ⅳ)和HCl浓度无关.混合液中CHCl提高,Ti-PILC的比表面积下降;当CHCl增至70mmol/L时,产物中大晶面间距消失,仅留下小晶面间距(~1.4nm).随着混合液中CTiCl4的提高,Ti-PILC的比表面积先上升而后下降。当CTiCl4增至146mmol/L时,产物也仅有小晶面间距(1.4nm).  相似文献   

9.
新型层柱微孔材料─GaW_9Z_3(Z=Co~(2+),Fe~(3+))柱撑ZnAl阴离子粘土的合成、表征及催化性能的研究张继余,余新武,张淑云,胡长文,梁兆君,王恩波(东北师范大学化学系,长春130024)关键词阴离子粘土,杂多化合物,过渡金属,催化性...  相似文献   

10.
柱撑阴离子粘土的合成、表征及催化性能研究(II)   总被引:13,自引:2,他引:13  
层柱状阴离子粘土可用化学通式口艺Ms”(OH):[A”叫。/n·YH。0表示,M’”、u’十分别为二、三价金属离子,l。一为层间阴离子.由于其具有独特的微初结构,对某些有机反应具有极高的活性和选择性,引起了人们的关注[‘,2].近年来,Pinnavaia等人[‘刘成功地合成了体积较大的同多及杂多含氧酸根柱撑的阴离子粘土,并发现ZnAI-VI。028对异丙醇光氧化成丙酮的反应具有极高的选择性.最近,笔者将过渡元素取代型三元杂多含氧酸根嵌入到ZnAINO。层间,并发现这些阴离子粘土对乙酸与正丁醉酯化反应具有较高活性和酯化选择性…  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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