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1.
非MAO的茂钛均相催化体系催化苯乙烯间规聚合———[CpTiMe3]/[Ph3C]+[B(C6F5)4]-催化体系许光学林尚安(中山大学高分子研究所广州510275)关键词茂钛络合物,茂金属催化剂,苯乙烯,间规聚苯乙烯间规聚苯乙烯(sPS)由于具...  相似文献   

2.
高分子负载催化剂在硝基苯加氢中的双金属协同效应   总被引:7,自引:0,他引:7  
高分子负载催化剂在硝基苯加氢中的双金属协同效应*郦海青廖世健**徐筠余道容(中国科学院大连化学物理研究所,大连116023)关键词聚乙烯吡咯烷酮,负载型催化剂,双金属催化剂,协同效应,硝基苯,加氢,苯胺在多相催化中,双金属和多金属催化剂是常见的,但在...  相似文献   

3.
钯催化下共轭烯烃的Heck芳基化是立体选择性形成碳碳键的重要方法,在有机合成中广为应用[1].均相钯催化剂因难以从反应体系中分离回收,其实际应用受到限制.聚合物负载过渡金属催化剂因综合了均相和复相催化过程的优势,已越来越引起人们的关注,聚苯乙烯负载的膦钯配合物能有效地催化共轭烯烃的芳基化[2,3].Zhang等报道了聚合物负载菲咯啉钯(0)配合物催化丙烯酰胺的芳基化[4],但该催化剂的制备过程过于复杂.作者曾报道过聚γ巯丙基硅氧烷钯(0)配合物的合成,并证实其是苯乙烯、丙烯酸Heck芳基化反…  相似文献   

4.
水溶性均相络合催化研究进展*   总被引:21,自引:0,他引:21  
本文评述了水溶性膦配体的合成及以水溶性过渡金属膦络合物为催化剂的两相催化体系的研究和开发概况, 着重介绍了两相体系在烯烃氢甲酰化、不饱和化合物的加氢及催化不对称合成中的应用, 并对两相催化体系研究中存在的问题进行了探讨。  相似文献   

5.
将水溶性酚醛树脂与金属盐溶液混合形成均相体系,依次通过减压蒸馏、固化、炭化、活化和预硫化处理制备负载金属硫化物的活性炭脱硫剂;研究其对羰基硫(COS)的加氢转化催化活性,考察了担载金属的种类、担载量、反应温度、反应时间和COS入口浓度等因素对催化反应的影响。研究结果表明,水溶性酚醛树脂是制备催化剂炭载体的理想前驱体;Ni Mo双组分催化剂对COS的加氢催化转化活性明显高于Mo单组分催化剂;在金属硫化物/活性炭催化剂上,COS的催化加氢过程属于内扩散控制,加氢反应气氛中一定浓度含硫组分的存在是抑制催化剂失硫及维持其催化活性的必要条件。  相似文献   

6.
膦配体TPPTS(三-间磺酸钠-三苯基膦)的水溶性很好,有关其过渡金属配合物催化剂的应用与研究活跃。近年来,对丙烯腈C=C双键加氢的研究多集中在以钯为中心金属的多相催化体系上,已报道的有聚硅氧烷钯体系,膦酸锆负载钯体系,高分子负载钯.金属氧化物催化剂,SiO2负  相似文献   

7.
聚丙交酯(PLA)可以生物降解,产物无毒,可用于外科手术的缝合线、人造器官以及药物缓释等方面,因此引起了人们的广泛注意.丙交酯的开环聚合是合成聚丙交酯的一种方便方法,所用的催化剂主要是主族及副族金属的配合物,如双金属氧桥配合物[‘j,烷基金属有机化合物[‘j,异丙氧基铝[’‘以及叶琳铝「“等.最近,关于三价烷氧基稀土化合物作为单组份催化剂催化丙交酯开环聚会已有报道[’·’‘.我们发现两价芳氧基稀土化合物(ArO)。Sin(THF)。(ArO一2,已二叔丁基一个甲基苯氧基)也可以有效地催化丙文酯的开环聚合.本…  相似文献   

8.
改变金属和载体的种类可以改变高分子催化剂的活性。本文在D3520负载的Pd催化剂中添加SnCl2.2H2I.FeCl3.6H2O,Pb(OH)2,BiCl3,形成D3520负载的金属氧化物──钯催化剂。研究结果表明,SnO2,Fe2O3的引入对原催化剂具有良好的助催化效果,其中Fe2O3的引入使原单位金属高分子催化剂对苯乙烯的催化加氢活性提高110%,PbO,Bi2O3的引入使催化加氢活性大大降低  相似文献   

9.
本文评述了高分子负载金属催化剂的分类及其高分子效应,重点评述了高分子负载金属络合物催化剂的载体功能基效应,多功能协同效应,高分子场效应和高分子基体效应,对高分子分散金属催化剂的高分子效应研究也作了一定的综述。  相似文献   

10.
本文了国内外对高分子负载烃歧化催化剂的研究概况。高分子固载化金属催化剂的研究始于六十年代末。由于高分子负载金属催化剂兼具均相和多相催化剂的优点,既具有均相催化剂的高活性又具多相催化剂的易回收分离,因而受到越多的高分子和催化工作者的重视。这种技术在加氢,氧化,脱氢,脱氢,环氧化,氢甲酰化,硅氢加成,不对称合成等有机催化领域都已得到不同程度的研究和应用,并获得了良好的效果,仅近年来就有许多综述和专著对  相似文献   

11.
The reaction of two equivalents of the functional phosphine ligand N-(diphenylphosphino)-1,3,4-thiadiazol-2-amine Ph2PNHC=NNCHS (2) with [PdCl2(NCPh)2] in the presence of NEt3 gives the neutral, P,N-chelated complex cis-[Pd(Ph2PN=CNN=CHS)2] ([Pd(2-H)2], 3b), which is analogous to the Pt(II) analogue cis-[Pt (Ph2PN=CNN=CHS)2] ([Pt(2-H)2], 3a) reported previously. These complexes function as chelating metalloligands when further coordinated to a metal through each of the CH-N atoms. In the resulting complexes, each endo-cyclic N donor of the thiadiazole rings is bonded to a different metal centre. Thus, the heterodinuclear palladium/platinum complexes cis-[Pt(Ph2PN=CNN=CHS)2PdCl2]([Pt(2-H)2·PdCl2], 4a) and cis-[Pd(Ph2PN=CNN=CHS)2PtCl2]([Pd(2-H)2·PtCl2], 4b) were obtained by reaction with [PdCl2(NCPh)2] and [PtCl2(NCPh)2], respectively. In contrast, reaction of 3a with [AuCl(tht)] occurred instead at the P-bound N atom, and afforded the platinum/digold complex cis-[Pt{Ph2PN(AuCl)=CNN=CHS}2] ([Pt(2-H)2(AuCl)2], 5). For comparison, reaction of 4a with HBF4 yielded cis-[Pt(Ph2PNH=CNN=CHS)2PdCl2](BF4)2([H24a](BF4)2, 6), in which the chelated PdCl2 moiety is retained. Complexes 3b, 4a·CH2Cl2, 4b·0.5C7H8, 5·4CHCl3 and 6 have been structurally characterized by X-ray diffraction.  相似文献   

12.
Solvation shells surrounding complex inorganic anions have not been extensively studied and are often mentioned with an amorphous picture in mind. We use a computational model previously validated against experimental results and ab initio quantum calculations (Lienke, A.; Klatt, G.; Robinson, D.; Koch, K. R.; Naidoo, K. J. Inorg.Chem. 2001, 40, 2352-2357) to investigate the nature of the hydration shells about simple platinum group metal chloro complexes ([PtCl(6)](2-), [RhCl(6)](3-), [PtCl(4)](2-), and [PdCl(4)](2-)). Our simulations show that the hydration shells surrounding these complexes are symmetric and take on familiar geometric forms. We find that only the [RhCl(6)](3-) complex has a clearly defined second hydration shell while the [PtCl(6)](2-), [PtCl(4)](2-), and [PdCl(4)](2-) second hydration shells are more diffuse.  相似文献   

13.
He XC 《Talanta》1991,38(3):319-323
The ion flotation of rhodium(III) and palladium(II) with some anionic surfactants has been investigated. Two flotation procedures are proposed for the separation of some platinum metals, based on differences in the kinetic properties of the chloro-complexes of rhodium(III), palladium(II) and platinum(IV). The first involves the selective flotation of Rh(H(2)O)(3+)(6) from PdCl(2-)(4) and PtCl(2-)(6) in dilute hydrochloric acid with sodium dodecylbenzenesulfonate (SDBS). After precipitation of the hydroxide and redissolution in dilute acid, the Rh(III) is converted into Rh(H(2)O)(3+)(6), Pd(II) and Pt(IV) remaining as PdCl(2-)(4) and PtCl(2-)(6) respectively, and separation is achieved by floating the Rh(H(2)O)(3+)(6) with SDBS. The second is for separation of Pd(II). Prior to flotation, the solution of PdCl(2-)(4) and PtCl(2-)(6) is heated with ammonium acetate to convert PdCl(2-)(4) into Pd(NH(3))(2+)(4). The chloro-complex of Pt(IV) is unaffected. The complex cation, Pd(NH(3))(2+)(4), is then selectively floated with SDBS. The procedures are fast, simple and do not require expensive reagents and apparatus.  相似文献   

14.
在聚乙二醇400-水绿色可循环介质中,以手性二胺(S,S)-1,2-二苯基乙二胺二磺酸钠((S,S)-DPENDS)与非手性钌膦络合物([RuCl2(TPPTS)2]2)原位生成的水溶性钌膦二胺为催化剂,考察了苄叉丙酮的选择性不对称加氢反应.在优化的反应条件下,羰基加氢产物4-苯基-3-丁烯-2-醇的化学选择性和对映选择性分别为98.5%和74.3%.经正己烷萃取后,催化剂即可从产物中分离出来.循环使用5次后,4-苯基-3-丁烯-2-醇化学选择性和对映选择性没有明显下降.  相似文献   

15.
Two different classes of silicone-modified ligands were prepared: nitrile derivatives, 4'-[3-(organosilyl)propoxy]biphenyl-4-carbonitrile R'3SiC3H6OC6H4C6H4CN (R'3Si- = a: Me3SiOSiMe2-, b: (Me(3)SiO)2SiMe-, c: Me3SiO(Me2SiO)3SiMe2-, d: Me3SiO(Me2SiO)25SiMe2-); and, pyridine derivatives, isonicotinic acid 2-methoxy-4-[3-(organosilyl)propyl]phenyl ester R'3SiC3H6Ph(O)MeOCOC5H4N . Compounds and were bound to Pd and Pt using ligand substitution reactions with organometallic precursors to give (R3SiC3H6OC6H4C6H4CN)2PdCl2, (R3SiC3H6OC6H4C6H4CN)2PtCl2 and (R3SiC3H6C6H3(OMe)OC(O)C5H4N)PtCl2(eta(2)-1-octene). The polydimethylsiloxane (PDMS)-supported Pt and Pd compounds and had excellent solubility in both organic solvents and polysiloxanes. All the Pt compounds exhibited good catalytic activity for hydrosilylation of vinylsilanes. The PDMS-supported Pd compound also was effective catalyst for hydrosilylation of a diene, isoprene, with 1,1,1,3,3-pentamethyldisiloxane MM(H) to produce the 1,4-adduct Me3SiOSiMe2CH2CH=CMeCH2-H as a major product.  相似文献   

16.
在可比条件下,研究了新型水溶性膦配体TOPPTS。Ln(TPPTS=三(间碘酸基苯基)膦,Ln=Y,La,Nd,Ho,Yb)分别与RhCl3、NiCl2、PbCl2组成的体系催化1-已烯氢甲酰化反应。结果表明,TPPTS。Ln-RhCl3(Ln-Y、Ho)的催化活性优于TPPTS。Na3-RhCl3体系(1-已烯的转化率分别为49.9%、38.8%、24.3%),有意义的是,TPPTS。Yb-NiCl2体系(转化率44.5%)亦高于TPPTS。Na3-RhCl3体系的催化结果,且稀土离子介入溶性膦配体后,使催化剂支支链醛的选择性明显提高。  相似文献   

17.
Russian Journal of Coordination Chemistry - Complexes [Co(NH3)6][PdCl4]Cl (I) and [Co(NH3)6]2[PtCl4]3 (II) are synthesized and characterized. Complex I is isolated for the first time. The...  相似文献   

18.
Under 254 nm irradiation in chloroform, [PdCl4]2- is protonated to H2PdCl4 by HCl, generated through absorption of light by CHCl3. This stands in contrast to the behavior of [PtCl4]2- and [Pt(bpy)Cl2], which undergo photooxidation under the same conditions.  相似文献   

19.
The synthesis and characterization of 10-(o-alkoxyphenyl)phenoxarsines 2-ROC6H4As(C6H4)2O (R = H, Me, and Pri, As(C6H4)2O = phenoxarsine) and their platinum(II) and palladium(II) complexes cis-[PtCl2{2-PriOC6H4As(C6H4)2O-kappaAs}2] (1), trans-[PdCl2{2-PriOC6H4As(C6H4)2O-kappaAs}2] (2), cis-[PtCl2{2-HOC6H4As(C6H4)2O-kappaAs}2] (3), cis-[PdCl2{2-HOC6H4As(C6H4)2O-kappaAs}2] (4), cis-[PtI2{2-MeOC6H4As(C6H4)2O-kappaAs}2] (5), and trans-[PdCl2{2-MeOC6H4As(C6H4)2O-kappaAs}2] (6) are reported. The chelate complex cis-[Pt{2-OC6H4As(C6H4)2O-kappaAs,O}2] (7) is also described. The molecular structures of 1-4 and 7 were determined. The short As...O intramolecular interaction found in complexes 1-4 in the solid state was also verified by calculations at the B3LYP/LANL2DZ level for complex 2 and for 10-(o-isopropoxyphenyl)phenoxarsine in the gas phase, and this suggests that the interaction is a characteristic of the ligand rather than a packing effect. Calculations at the B3LYP/LANL2DZ and Oniom(B3LYP/LANL2DZ:uff) levels for complexes 1-4 showed that the solvent plays a crucial role in the crystallization (through geometry constraints) of the kinetically stable cis isomers.  相似文献   

20.
PdCl(2)(CH(3)CN)(2) and [PtCl(2)(H(2)C[double bond]CH(2))](2) catalyze the addition of beta-dicarbonyl compounds to ethylene and propylene.  相似文献   

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