三甲硅基环戊二烯基稀土二氯化物的合成

1978年Lappert等人首先合成了二(三甲硅基环戊二烯基)稀土氯化物[Li(THF)](Me_3SiC_5H_4)_2LnCl] (Ln=Y,Yb)和Yb(C_5H_4SiMe_3)_2。三甲硅基环戊二烯基稀土二氯化物,则未见报导.采用三甲硅基环戊二烯作为合成稀土金属有机化合物的配体,不仅可以增加所合成的稀土化合物在非极性溶剂中的溶解度,而且在反应过程中可以减小歧化反应的发生,得到所要求的产物.我们探索了三甲硅基环戊二烯基稀土二氯化物的合成,并对所得到的产物进行了鉴定.     

三甲基硅基淀粉醚的合成

本文以淀粉和三甲基氯硅烷(TMS-Cl)为原料,在吡啶中合成了三甲基硅基淀粉醚(TMSS).详细研究了反应温度、时间、吡啶以及三甲基氯硅烷(TMS-Cl)用量等对TMSS产率的影响.红外及核磁图谱表明,三甲基硅基被成功地引入淀粉的分子骨架.     

聚三甲硅基丙炔的紫外辐照研究I．聚三甲硅基丙炔均质膜在空气中的紫外辐照

聚１－三甲硅基丙炔膜经紫外线辐照后其氧氮选择性提高，用ＸＰＳ及水接触角法研究了膜的表面组成对透气性的影响。     

聚1—三甲硅基丙炔膜的溴化和气体透过性

在新的气体分离膜材料中,聚1-三甲硅基丙炔(PTMSP)以其高的气体透过性和优异的成超薄膜性而引起各方面的兴趣。目前的研究热点是如何提高PTMSP的氧氮透过分离系数(ao_2/N_2)和气体透过稳定性。Langsam用氮稀释的氟气对PTMSP膜进行表面氟化处理,大幅度地提高了膜的ao_2/N_2,但处理过程中伴随着剧烈的裂解,控制困难。Gozds以N-溴代丁     

乙基纤维素三甲硅基衍生物膜的结构表征与氧氮渗透行为

Characterization of ethyl cellulose and its derivative membranes EC-SiMe3 was studied by ¹H-NMR, ¹³C-NMR, solids-state ¹³C-NMR(CPMAS) and IR spectra. The permselectivity for oxygen and nitrogen of EC-SiMe3 membranes was determined.     

二(三甲硅基环戊二烯基)二氯合锆的合成和晶体结构

在 THF中 ,通过三甲硅基环戊二烯基锂与四氯化锆反应合成了标题化合物 ,经元素分析 ,IR和 1 H NMR谱表征了其结构 ,并用 X-射线衍射测定了晶体结构 ,该晶体属于三斜晶系 ,空间群为 P1 ,晶体学参数 :a=0 .6787(6) ,b=1 .2 92 4 (2 ) ,c=1 .30 34(2 ) nm,α=67.83(1 ) ,β=82 .50 (3) ,γ=75.64 (3)°,V=1 .0 2 5nm3 ,Z=2 ,Dx=1 .41 5 g· cm-3 ,μ=8.989cm-1 ,F (0 0 0 ) =448,R=0 .0 32。质谱研究表明 ,化合物在质谱过程中发生二聚 C*p2 ZrClZr C*P2Cl(C*P=C5H4Si Me3 )。     

双[1,3-二(三甲硅基)环戊二烯基]四羰基二铁的反应性

题示化合物分子中的铁铁键被钠汞齐还原断裂, 生成相应的单核铁负离子, 后者分别与PhCOCl, PhCH~2Cl,ClCH~2COOC~2H~5, Ph~3SnCl 及Ph~2SnCl~2进行亲核取代反应,生成在铁原子上引入相应取代基的产物。题示化合物分别与卤素和二氯化汞反应, 生成铁铁键断裂的铁卤化物和铁氯汞化物。用X-射线测定了题示化合物与Ph~3SnCl反应生成产物的晶体和分子结构。     

CCl4等离子体表面改性聚三甲硅基丙炔膜

ＣＣｌ_４等离子体表面改性聚三甲硅基丙炔膜邱雪鹏，许观藩，林晓，郑国栋，徐纪平（中国科学院长春应用化学研究所长春１３００２２）关键词聚三甲硅基丙炔，等离子体改性，氧氮气体透过选择性聚三甲硅基丙炔（ＰＴＭＳＰ）具有优异的气体透过性，但其氧氮选择性差，可?..     

片呐酮的烯醇三甲基硅醚在紫外光照下的氟烷基化反应

酮的烯醇硅醚的富电子碳碳双键易被亲电子基团进攻,生成取代酮类化合物。例如,在TiCl_4等Lewis酸的存在下,卤代烷与酮的烯醇三甲硅醚反应生成2-烷基取代酮。迄今为止,还没有卤代氟烷与酮的烯醇非醚反应研究的报道。我们将3,3-二甲基-2-丁酮的烯醇三甲硅醚与等摩尔的1,1,1-三氟-2,2,2-三溴乙烷及催化量的过氧化月桂酰进行光照3h后,б_F-10 ppm处出现一新峰,与CF_3CBr_3(2)的δ_F0 ppm处峰的面积比为2:3。继续光照,δ_F-     

Trifluoromethylthiolation of Trimethylsilyl Enol Ethers

The treatment of bis-(1,2-trimethylsilyloxy)-1-cyclobutene, 1-(1-trimethylsilyloxy)cyclpentene and 1-(1-trimethylsilyloxy)cyclohexene with trifluoromethylsulfenyl chloride has been found to furnish trifluoromethylthiolated carbonyl derivatives.     

异龙脑甲醚断裂反应的研究

研究了异龙脑甲醚在三氯化铁 /乙酸酐存在下的断裂反应 ,并详细讨论了三氯化铁用量、反应时间和反应温度对断裂反应的影响。     

Trimethylsilyl Cyanide Addition to Carbonyl Compounds Under Neutral Condition Catalyzed by Iodine

Reaction of trimethylsilyl cyanide with aliphatic or aromatic aldehydes and ketones in the presence of a catalytic amount of elemental iodine produced the corresponding cyanohydrin trimethylsilyl ethers in very short time and high yields.     

Trimethylsilyl fluorosulfonyldifluoroacetate (TFDA): a new, highly efficient difluorocarbene reagent

TFDA is readily prepared from the reaction of fluorosulfonyldifluoroacetic acid with trimethylsilyl chloride, and it is a very effective and efficient source of difluorocarbene for use in addition reactions to alkenes of a broad scope of reactivities. Acid-sensitive substrates may require an additional purification step involving treatment of the distilled TFDA with sufficient Et₃N to remove the acid impurity. Other trialkylsilyl fluorosulfonyldifluoroacetates can also be prepared, and they have been found to have reactivities similar to TFDA. The triethyl derivative, TEFDA is more convenient to prepare in a pure state and has similar reactivity to TFDA. Thus, it may prove to be a superior reagent.     

聚醚醚酮酮（PEEKK）和含联苯结构聚醚醚酮酮（PEBEKK）共聚物的SAXS研究

应用一维电子密度相关函数方法，对含不同联苯结构的ＰＥＥＫＫ－ＰＥＢＥＫＫ共聚物样品小角Ｘ射线散射（ＳＡＸＳ）去模糊强度分析计算表明：ＰＥＥＫＫ－ＰＥＢＥＫＫ共聚物的聚集态结构明显地依赖于共聚物中联苯含量。当联苯含量ｎｂ＝０．３５时，积分不变量Ｑ，长周期Ｌ，平均结晶片层厚ｄ，电子密度差η_ｃ－η_ａ和结晶度Ｗ_（ｃ，ｘ）值为最小，比表面积Ｏ_ｓ为最大。     

Trimethylsilyl isothiocyanate (TMSNCS): an efficient reagent for the one-pot synthesis of mercapto-1,2,4-triazoles

A mild, convenient, and efficient one-pot synthesis of mercapto-1,2,4-triazoles is described. Various hydrazides efficiently reacted with trimethylsilyl isothiocyanate (TMSNCS) under basic condition to give mercapto-1,2,4-triazoles in high yields.     

Trimethylsilyl Chloride Aids in Solubilization of Oxidative Addition Intermediates from Zinc Metal

Trimethylsilyl chloride (TMSCl) is commonly used to “activate” metal(0) powders toward oxidative addition of organohalides, but knowledge of its mechanism remains limited by the inability to characterize chemical intermediates under reaction conditions. Here, fluorescence lifetime imaging microscopy (FLIM) overcomes these prior limitations and shows that TMSCl aids in solubilization of the organozinc intermediate from zinc(0) metal after oxidative addition, a previously unknown mechanistic role. This mechanistic role is in contrast to previously known roles for TMSCl before the oxidative addition step. To achieve this understanding, FLIM, a tool traditionally used in biology, is developed to characterize intermediates during a chemical reaction—thus revealing mechanistic steps that are unobservable without fluorescence lifetime data. These findings impact organometallic reagent synthesis and catalysis by providing a previously uncharacterized mechanistic role for a widely used activating agent, an understanding of which is suitable for revising activation models and for developing strategies to activate currently unreactive metals.     

Guaiacol transprotection: replacement of the phenoxy isopropyl protecting function by acetyl

A one-step method for the conversion of isopropyl protected guaiacols to the corresponding acetates is reported. Treating 6-substituted isopropyl protected guaiacols with trimethylsilyl trifluoromethanesulfonate in a mixture of acetic anhydride and acetonitrile affords 6-substituted guaiacol acetates in yields ranging from 35% to 99%.     

Hydroxyl group deprotection reactions with Pd(OH)2/C: a convenient alternative to hydrogenolysis of benzyl ethers and acid hydrolysis of ketals

Benzyl ethers, ketals and orthoformates were cleaved with Pd(OH)₂/C in methanol, to generate the corresponding alcohol; carboxylic acid esters were stable under these reaction conditions. Pd(OH)₂/C in methanol was used for the deprotection of hydroxyl groups during the preparation of sequoyitol via myo-inositol orthobenzoate. This method of deprotection has the potential to be useful in the synthesis of different classes of organic compounds since the reaction conditions do not involve strong acids, bases or hydrogen.