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1.
以硅胶为载体, 采用键合接枝法将2-(二苯膦基)乙基三乙氧基硅烷(DPPES)共价键合于硅胶表面, 制备了性能优良的硅胶键合型膦配体(以SiO2(PPh2)表示). 以SiO2(PPh2)为配体, Rh(acac)(CO)2 (acac:乙酰丙酮)为催化前体, 负载铑膦络合物催化剂(SiO2(PPh2)/Rh)在1-辛烯氢甲酰化反应中原位生成. 对生成的负载型催化剂和硅胶键合型膦配体进行了傅里叶变换红外(FTIR)光谱表征, 考察了膦/铑摩尔浓度比([P]/[Rh])、温度等因素对铑催化的长链1-辛烯氢甲酰化反应的影响. 结果表明, 膦/铑摩尔浓度比的增加能显著提高反应的成醛选择性, 降低铑的流失. 在[P]/[Rh]=12、363 K、2.0 MPa、1.5 h 的温和反应条件下, 1-辛烯转化率和成醛选择性分别可达98.4%和95.3%, 其催化活性与DPPES或三苯基膦(TPP)作配体时的均相铑催化相近. 催化剂循环4 次后, 反应活性无明显下降, 1-辛烯转化率均在97.0%左右, 经电感耦合等离子体原子发射光谱(ICP-AES)检测,有机相中铑流失低于0.1%.  相似文献   

2.
以氨基酸和1,5-环辛二烯(cod)为配体的铑催化剂催化苯乙炔和2,4-二羟基苯甲醛的氧化偶联反应,并合成了2-苯基-7-羟基-1H-色酮-4-酮.研究了以不同氨基酸为配体的铑催化剂对相同底物的催化效果,结果发现,在相同反应条件下,Rh(cod)(L-Phe)的催化效果最佳.  相似文献   

3.
二羰基水杨醛肟铑配合物催化的苯乙烯常压氢甲酰化反应   总被引:2,自引:0,他引:2  
用Rh~2(CO)~4Cl~2与水杨醛肟的钠盐反应合成了二羰基水杨醛肟铑配合物Rh(sox)(CO~2)(1)。在常压下研究了该配合物与膦或亚磷酸酯组成的体系对苯乙烯氢甲酰化反应的催化性能, 此体系对烯烃没有催化加氢作用, 产物醛的化学选择性均为100%。考察了膦的结构与用量对催化活性和选择性的影响, 双膦作配体时活性和选择性都高于单膦, 其中Rh(sox)(CO)~2-Ph~2P(CH~2)~3PPh~2体系的最高初活性(TON)可达1.60min^-^1, 2-苯基丙醛的选择性在90%以上。对反应的活性物种作了初步讨论。  相似文献   

4.
本文用含有多胺、多(胺基膦)和单齿的胺基膦、亚磷酸酯等配位基团的功能基化交联聚苯乙烯与二氯四羰基二铑反应得到了10种聚合物配位体络铑催化剂。用这些催化剂进行了二异丁烯的催化氢甲酰化反应(反应条件:110℃;100,80,60kg/cm~2;H_2/CO=1:1;6h;苯为溶剂),大多数催化剂表现出了良好的催化性能。催化剂的红外光谱证明了聚合物多胺配位体与铑活性中心之间具有多齿配位结构。文中还对催化过程的铑脱落现象进行了研究,讨论了配位体结构与铑脱落量及催化活性的关系,测定了铑脱落量与催化剂使用次数关系的曲线,考察了反应条件及外添加试剂对铑脱落的影响,并提出了催化剂可能的铑脱落机制。  相似文献   

5.
研究了由 Rh(acac) (CO) 2 和 1 ,4-双 (二苯膦基 )苯 (简称 DPPB)组成的体系对烯烃氢甲酰化反应的催化作用 .考察了反应温度、压力、P/Rh比、催化剂浓度等对 1 -己烯氢甲酰化反应的影响 ,得到了较适宜的反应条件 .在相同条件下比较了该体系催化 1 -己烯、 1 -辛烯、 1 -十二烯的氢甲酰化反应的性能 .结果表明 ,随着底物碳链的增长 ,反应活性呈提高趋势 .实验证明 ,DPPB-铑配合物对苯乙烯的氢甲酰化反应有较高的催化活性和选择性 .  相似文献   

6.
用量子化学 AMI方法优化了 1 -苯基二苯并膦二磺化产物 ( PDBPDS)和三磺化三苯基膦 ( TPPTS)的几何构型 .比较两种化合物的空间结构和电子结构发现 ,在氢甲酰化铑膦催化反应体系中 ,PDBPDS的配体性能优于 TPPTS.首次研究了以 PDBPDS为配体的铑膦催化剂对丙烯氢甲酰化反应的催化性能 ,考察了反应温度、压力、膦铑物质的量比和搅拌速度对催化活性和选择性的影响 .结果表明 ,在 2 .0 MPa,1 0 0℃ ,膦铑物质的量比为 35 ,搅拌速度为 5 0 0 r/min及 V( H2 ) /V( CO) =1 /1的条件下 ,催化活性可达到 2 80 0 g(丁醛 ) /[g(铑 )·h],正异构产物物质的量比为 1 2 .3,在相同条件下与传统的三磺化三苯基膦 ( TPPTS)为配体的铑膦催化剂相比 ,催化活性和选择性提高了 2倍 .反应结束后 ,有机相和水相分离简单 ,有机相铑浓度仅为3.6× 1 0 - 8mol/L,有效地解决了铑流失问题 ,表明 PDBPDS是极具开发前景的新型水溶性配体  相似文献   

7.
付海燕  郭妤  林棋  陈华  李贤均 《催化学报》2006,27(12):1053-1058
 考察了新型表面活性膦配体DPPTS(对-十二烷基苯基二苯基膦的磺酸钠盐)和OPPTS(对-辛基苯基二苯基膦的磺酸钠盐)在铑络合物催化的水/有机两相长链烯烃氢甲酰化反应中的助催化作用. 在催化烯烃氢甲酰化反应时,观察到烯烃与膦配体之间有一定的链长匹配效应; 含DPPTS的催化剂体系在低膦/铑比条件下表现出比含表面活性剂十六烷基三甲基溴化铵和水溶性配体三苯基膦三磺酸钠的催化剂体系高得多的催化活性,而且铑流失到有机相极少,仅为加入总铑量的0.8%. 这种亲水基团和磷原子处于碳链同一端的表面活性膦配体比文献报道的亲水基团和磷原子分别处于碳链两端的表面活性膦配体具有更好的助催化活性.  相似文献   

8.
以溶胶-凝胶与锚链固定相结合的方法制备了新型多相化羰基铑膦配合物催化剂.利用FT-IR,XPS和ICP对催化剂进行了表征.考察了该催化剂对1-己烯氢甲酰化反应的催化性能,得到较佳的反应条件,即反应温度100℃、反应时间12h、催化剂用量为0.3382g(相当于金属铑含量为4.4×10-5mol)、反应压力5.0MPa.此时1-己烯的转化率为98.5%、醛的选择性92.4%、n/i比1.43.该催化剂循环使用7次仍具有较高的催化活性和选择性,表明该催化剂具有好的循环使用性能.XPS、ICP分析证明铑的部分流失主要是由于氢甲酰化反条件下CO取代膦配体所致.  相似文献   

9.
将 1-苯基二苯并膦 (PDBP)作为膦配体用于丙烯氢甲酰化反应中 ,系统研究了反应温度、压力、铑浓度、搅拌速率对产物丁醛收率的影响 .在铑浓度为 4.0× 10 - 6 、 P/ Rh比为 15 0、温度 10 0℃、反应压力 2 .0 MPa的条件下 ,丙烯转化率可达 90 % ,催化活性为 2 6 0 9g丁醛 / (g Rh· h) ,正丁醛和异丁醛的比达 9.5 .在相同的条件下与工业上广泛采用的以三苯基膦为配体的铑催化剂相比较 ,以 PDBP为配体的铑催化剂的活性和选择性分别是它的 1.44倍和 1.90倍 .证明了 PDBP是一个很有发展前景的羰基合成的膦配体  相似文献   

10.
曹维良  唐波  张敬畅  严斌 《分子催化》2001,15(5):335-340
以新型水溶性二磺化 - 1-苯基二苯并膦 (简称 PDBPDS)为配体 ,制备了铑膦配合物 Rh(acac) (CO ) -(PDBPDS) 3.将其负载于高吸水性载体上 ,制得负载水相催化剂 ,并对催化剂的制备条件进行了优化 .以人造沸石为载体 ,在载水量 30 % ,[Rh]=2 .0× 10 - 5、 [P]/ [Rh]=40的条件下 ,筛选出丙烯氢甲酰化反应的最佳工艺条件 .在反应温度 10 0℃、压力 2 .0 MPa、搅拌速度为 5 0 0 r/ m in条件下 ,催化剂活性达 10 12 g丁醛 / (g Rh· h) ;正异比高达 43.5 ;在有机相中铑的浓度为 1.2× 10 - 9,解决了均相反应催化剂回收和循环使用的问题 .实验结果表明 ,新型配体二磺化 - 1-苯基二苯并膦是一性能较好的新配体 ,所制备的新型负载水相催化剂是一有较好开发前景的新型催化剂  相似文献   

11.
The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997.  相似文献   

12.
非那雄胺能抑制5α-还原酶的活性,明显降低二氢睾酮水平,是一种治疗良性前列腺增生的有效药品。该合成工艺以甾烯酮酸为原料,将其与氯化亚砜反应,无须分离即与叔丁胺反应得17β-酰胺化合物,再氧化开环,环合,氢化,脱氢合成了非那雄胺。经元素分析、IR、1HNMR、13CNMR、MS分析表征了其结构。该法无须使用昂贵的2,2-二吡啶二硫化物和剧毒药品苯亚硒酸酐,且以乙酸铵代替氨气,降低了对设备的要求和腐蚀,更适用于工业生产。  相似文献   

13.

The heats of detonation of 20 simple high explosives and explosive mixtures were determined by means of an adiabatic detonation calorimeter designed by the authors. The results indicated that the performance of the instrument was reliable and the experimental data were very accurate. For explosive mixtures, there was a linear accumulative relationship between the heats of detonation of the explosive mixture and its components. Accordingly, the heats of detonation of explosive mixtures could be calculated directly from the heats of detonation of simple explosives and the characteristic heats of other components. The experiments showed that the gold or brass shell of the cylindrical charge could be substituted by a thick-walled porcelain shell, which had the advantage of cheapness.

  相似文献   

14.
Two vanilloids, (5E)-8-(4-hydroxy-3-methoxyphenyl)oct-5-en-4-one (1) and 4-[3-hydroxydecyl]-2-methoxyphenol (2), isolated from the dried seeds of Grains of Paradise (Aframomum melegueta), were synthesized; the latter compound was made as the S-enantiomer and the material derived from the seeds was found to be a 1:1.7 mixture of the R and S isomers. The synthetic route used should allow the preparation of analogs having extended alkyl chains and consequently different lipophilicity, and 3, a homolog of 2, was also prepared.  相似文献   

15.
In this review, the research of the author in the field of colloidal systems is summarized. The factors influencing colloidal stability are systematized and analyzed. Examples are presented to illustrate the practical utilization of the theory of stability of colloids and thin films.This review was prepared on the basis of the works of the author, which were awarded the State Premium for 1991 in the field of science and technology, chemistry section.Institute of Physical Chemistry, Russian Academy of Sciences, 117915 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 8, pp. 1708–1717, August, 1992.  相似文献   

16.
Main hydration products of two cement pastes, i.e. CSH-gel, portlandite (P) (and specific surface S) were studied by static heating, and by SEM, TEM and XRD, as a function of cement strength (C-33 and C-43) hydration time (th) and subsequent hydration in water vapour.Total change in mass on hydration and air drying, Mo, increased with strength of cement paste and with hydration time. Content of water escaping at 110 to 220°C, defined as water bound with low energy, mainly interlayer and hydrate water, was independent on cement strength but its content increased with (th). Content of chemically bound (zeolitic) water in CSH-gel, escaping at 220-400°C, was slightly dependent on strength and increased with (th). It was possibly derived from the dehydroxylation of CSH-gel and AFm phase. Portlandite water, escaping at 400-500°C, was independent on cement strength and was higher on longer hydration. Large P crystals were formed in the weaker cement paste C-33. Smaller crystals were formed in C-43 but they increased with (th). Carbonate formated on contact with air (calcite, vaterite and aragonite), decomposed in cement at 600-700oC. It was high in pastes C-33(1 month) and C-43(1 month), i.e. 5.7 and 3.3%, respectively; it was less than 1% after 6 hydration months (low sensitivity to carbonation) in agreement with the XRD study showing carbonates in the air dry paste (1month), and its absence on prolonged hydration (6 months) and on acetone treatment. Water vapour treatment of (6 months) pastes or wetting-drying increased this sensitivity.Nanosized P-crystals, detected by TEM, could contribute to the cement strength; carbonate was observed on the rims of gel clusters.This revised version was published online in November 2005 with corrections to the Cover Date.  相似文献   

17.
翟宗玺  刘树深  夏树屏 《化学学报》1990,48(10):946-950
用氧化镁氯化镁水溶液制备了8水合氯氧化镁[nMg(OH)2·MgCl2·8H2O], 并测定了其在盐酸中的溶解热, 实验结果表明, 氯氧化镁溶解热与n值呈线性关系, 根据溶解热求出5Mg(OH)2·MgCl2·8H2O和3Mg(OH)2·MgCl2·8H2O的生成热分别为-7727.1和5888.1kJ·mol^1^-。  相似文献   

18.
The enthalpies of solution of several oxosulfides of rare-earth elements and the high-temperature enthalpies of oxosulfides and oxosulfates of lanthanum and yttrium were measured using solution calorimetry and high-temperature microcalorimetry techniques. Standard enthalpies of formation and some thermodynamic properties of oxosulfides and oxosulfates were calculated. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2 pp. 294–297, February, 1997.  相似文献   

19.
20.
设计了铁的锈蚀实验,说明了铁钉的处理方法,增加了温度、酸、碱的影响条件,实现了铁跟蒸馏水及空气中氧气快速反应而生锈,使实验在5 min左右就能够得到准确的结果。  相似文献   

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