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1.
考察了一系列含不同取代基团的三芳基膦配体对RhCl3催化硅氢加成的影响,结果表明:当三(2-甲氧基苯基)膦作为配体时,RhCl3能有效地催化硅氢加成,催化剂的催化活性最好;当温度达到100℃、反应5h、三(2-甲氧基苯基)膦与RhCl3催化剂的比例为5∶1时,转化率最高,催化效果最佳.  相似文献   

2.
合成了一系列含不同基团的三芳基膦配体,并考察其对Karstedt催化剂催化硅氢加成反应的影响.结果表明,含氨基、羧基、烷基等基团的三芳基膦配体有抑制作用,而含硅基官能团的三芳基膦配体则可提高Karstedt催化剂催化活性,同时提高了β加成物的选择性.当催化剂用量为0.5‰,7a配体含量与 Karstedt (0.5‰相对苯乙烯)的比例为6∶1,催化效果最佳.  相似文献   

3.
在温和条件下合成了两种水溶性膦配体:三(4-甲氧基-3-磺酸钠苯基)膦(简称:4-MOTPPTS)和三(2-甲氧基-3-磺酸钠苯基)膦(简称:2-MOTPPTS).在水/有机两相体系中,以RhCl(CO)(TPPTS)2为催化剂前体,考察了4-MOTPPTS和2-MOTPPTS作为配体时,膦/铑摩尔比、反应温度和压力变化对1-十二烯氢甲酰化反应催化性能的影响.结果表明,与三(3-磺酸钠苯基)膦(简称TPPTS)相比,在苯环上引入甲氧基后,其供电特性使催化剂对烯烃氢甲酰化反应的活性和生成醛的选择性不利,而邻位甲氧基的引入所造成的空间位阻,使2-MOTPPTS表现出较4-MOTPPTS更低的催化活性和选择性.但与相应的油溶性膦配体相比,对生成醛的选择性明显增加.  相似文献   

4.
利用发烟硫酸磺化手性双胺双膦配体[(R.R)-C6P2(NH)2].合成了PNNP-型水溶性手性双胺双膦配体[(R.R)-C6P2(NH)2(SO3Na)4],并分别与简单的钌、铑络合物反应,制备水溶性手性钌络合物催化剂[(R,R)-C6P2(NH)2(SO3Na)4RuCl2]和铑络合物催化剂[(R,R)-C6P2(NH)2(SO3Na)4RhCl].经元素分析、红外光谱和核磁共振等对手性配体及手性Ru络合物进行了结构表征.进而用这些水溶性的钌,铑络合物催化剂或水溶性手性配体与铱络合物[IrHCl2(COD)]2组成的混合催化体系研究了多种芳香酮的不对称转移氢化。结果表明.在以异丙醇作为氢源时.对芳香酮的不对称转移氢化都具有较好的催化活性.与铑,铱催化体系相比,水溶性手性钌络合物催化体系具有更高的活性和对映选择性.对于苯乙酮的氢化.其转化率和对映选择性分别达到91.6%和93.0%e.e..此外,进一步考察了反应温度和KOH用量对水溶性手性钌络合物催化苯乙酮不对称转移氢化性能的影响,并将水溶性手性钌络合物催化体系应用于多种芳香酮的不对称转移氢化,获得了高的收率和对映选择性,分别可达92.0%和96.4%e.e..研究结果表明,水溶性手性钌络合物[CR.R)-G6P2(NH)2(SO3Na)4RuCl2]是芳香酮不对称氢转移催化氢化的优良催化剂.  相似文献   

5.
合成了结构中同时含有氮和磷的新型手性希夫碱,将希夫碱与金属配合物结合催化α-苯基-α-重氮乙酸甲酯与硅氢化合物的不对称硅氢插入反应,考察了不同的金属铜配合物和希夫碱对反应的影响,探讨了手性希夫碱/金属配合物催化体系对不同硅氢底物的适应性.当采用希夫碱4与Cu(CH3CN)4PF6的催化体系催化α-苯基-α-重氮乙酸甲酯与二甲基苯基硅烷的不对称硅氢插入反应时,反应具有优良的产率(100%)和对映选择性(76%).  相似文献   

6.
β-(3,4-环氧环己基)乙基三甲氧基硅烷的合成   总被引:1,自引:0,他引:1  
用不同配体的Pt配合物催化三甲氧基硅烷(TMOS)与1,2-环氧-4-乙烯基环己烷(EVCX)的硅氢加成反应合成了β-(3,4-环氧环己基)乙基三甲氧基硅烷.通过气质联用仪对反应产物进行分析,确定了主产物的结构.讨论了催化剂用量、反应温度等条件对反应的影响,筛选出了最佳的的反应条件.Pt-C38H34N2P2催化剂用量为40ppm表现出最佳的催化活性,当反应控温在80-90℃之间,β-(3,4-环氧环己基)乙基三甲氧基硅烷的产率可达80%以上.  相似文献   

7.
研究了在以水溶性铑膦络合物RhCl(CO)(TPPTS)2为催化剂的两相体系中,反应温度、压力、膦铑比、催化剂浓度、CO/H2分压比、底物浓度等对1-丁烯氢甲酰化反应的活性和区域选择性的影响.结果表明,RhCl(CO)(TPPTS)2对水/有机两相催化体系1-丁烯氢甲酰化反应表现出良好的活性和区域选择性,在100℃,2.5MPa,[TPPTS]/[Rh]=25时,生成戊醛的TOF高达2500h^-1,生成正戊醛的选择性达到87.5%.  相似文献   

8.
研究了Ni(dpm)2Cl2-CuCl(dpm为Ph2PCH2PPh2)对甲基丙烯酸甲酯(MMA)与聚氢甲基硅氧烷(PHMS)硅氢加成的催化性能,讨论了影响反应的因素,结果表明:Ni-Cu催化体系对MMA与PHMS的硅氢加成反应具有一定的催化效果,硅氢化接枝率可达到50%,在硅氢加成反应的同时伴随着MMA的热聚合反应发生,随着催化剂用量的增大,反应速率加快,接枝率相应增高,MMA的热聚合则相应减少;随着反应温度的升高,反应速率加快,但MMA的热聚合也随之明显增多。  相似文献   

9.
报道了4个C2对称手性四氮配体(2a‐d)的合成及其催化苯乙酮的不对称转移氢化,催化反应具有较高的转化率(90%~98%)和适中的对映选择性(2%~60%).用X‐射线单晶衍射仪对配体2d{(R,R,S,S,S,S)‐1,3‐Di[4,5‐diphenyl‐1‐(p‐toluenesulfonyl)‐2‐imidazolidine]benzene}进行了结构表征,单斜晶系,手性空间群P1211,Z=2,a=10.4814(6),b=9.4332(5),c=21.8758(14)?,V =2161.7(2)?3,M r=829.01,Dc=1.274 g/cm3,F(000)=872,最终 GOF=1.023,R=0.0518和 wR=0.1096.  相似文献   

10.
以氯铂酸-胺体系为催化剂的硅氢加成法合成甲基(γ-氯丙基)二氯硅烷,考察了反应温度、原料配比、催化剂用量、反应时间等因素对反应产物收率的影响,选择出最佳工艺条件,硅氢加成收率达到81%.  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

13.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

14.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

15.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

16.
本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。  相似文献   

17.
There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.  相似文献   

18.
19.
The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to  相似文献   

20.
Various applications relevant to the exciton dynamics,such as the organic solar cell,the large-area organic light-emitting diodes and the thermoelectricity,are operating under temperature gradient.The potential abnormal behavior of the exicton dynamics driven by the temperature difference may affect the efficiency and performance of the corresponding devices.In the above situations,the exciton dynamics under temperature difference is mixed with  相似文献   

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