Silicon α-Effect: A Systematic Experimental and Computational Study of the Hydrolysis of C<sub>α</sub>- and C<sub>γ</sub>-Functionalized Alkoxytriorganylsilanes of the Formula Type ROSiMe<sub>2</sub>(CH<sub>2</sub>)<sub><i>n</i></sub>X (R = Me, Et; <i>n</i> = 1, 3; X = Functional Group)
demonstrated that the silicon α-effect cannot be rationalized in terms of a special single effect. The reactivities observed rather result from a summation of different components, such as electronic and steric effects, pD dependence, and hydrogen bonds between the functional group (or even protonated functional group) and the alkoxy leaving group. Therefore, the term “silicon α-effect” should not be used furthermore
为了理解在式类型ROSiMe的α-硅烷中的Si-OC键的增强的反应性方面的硅α-效果2 CH 2 X相比类似的γ-硅烷ROSiMe 2(CH 2)3 X(R =我等; X =官能团),一个系统的实验和动力学和这样的化合物的水解的机制的计算研究进行。为了这个目的,一系列合适的模型化合物的合成和在CD研究了它们的水解动力学3 CN / d 2 o在碱性和酸性条件下,使用1H NMR光谱作为分析工具。为了获得有关反应机理的更多信息,实验研究得到了计算研究的补充。这些研究表明,硅α效应不能通过特殊的单一效应来合理化。观察到的反应性实际上是由不同成分的总和产生的,例如电子和空间效应,pD依赖性以及官能团(甚至是质子化的官能团)与烷氧基离去基团之间的氢键。因此,不应再使用术语“硅α-效应”来解释在有机基的α-或γ-位带有官能团的烷氧基有机基硅烷在硅原子上的水解反应性(所谓的α-或γ-硅烷)。
Persistence of the effects of Jet-A in a microcosm with releases from the sediment
作者:Randy S. Sandberg、Wayne G. Landis
DOI:10.1002/etc.5620200912
日期:2001.9
functional level effects of a release of a complex hydrocarbon mixture fromsediments using a 60-d modified mixed flask culture (MFC) microcosm. Neat Jet-A was injected and mixed into the sediment with one nondosed and three dosed concentrations. Univariate and multivariate statistical and graphical techniques were used to detect patterns in the data. A slow release of the test material from the spiked sediment
It has been found that the reaction of the 1,2-ethanediylbis(trithiocarbonic acid) dianion with haloacetic esters, chloromethyl ethers, and chlororhethyl sulfides in tetrahydrofuran proceeds smoothly to afford 1,2-ethanediylbis(alkoxycarbonylmethyl trithiocarbonates), 1,2-ethanediylbis(alkoxymethyl trithiocarbonates) and bis(alkylthiomethyl) trithiocarbonates plus ethylene trithiocarbonate respectively
1-Heteroakylation of tris(trimethylsilyl)phosphine
作者:Andrey A. Prishchenko、Mikhail V. Livantsov、Olga P. Novikova、Ludmila I. Livantsova、Valery S. Petrosyan
DOI:10.1002/hc.20636
日期:——
1-heteroalkylation of the tris-(trimethylsilyl)phosphine was thoroughly investigated using heterosubstituted methylamines, chloromethyl alkyl ethers, methyl chloroformate, paraformaldehyde, and dialkylformamides. Convenient methods for the synthesis of tris(dialkylaminomethyl)phosphines, tris(alkoxymethyl)phosphines, tris(methoxycarbonyl) phosphine, and several phosphaethylenes were proposed on the basis
A new one-step procedure is described for the synthesis of disubstituted imidazolium chlorides. 1,3-Dialkoxymethylimidazolium chlorides thus obtained can be employed as synthetic precursors of symmetrical ILs. The salts have been found to exhibit antimicrobial activity and an antielectrostatic effect. Their densities and viscosities have been determined and are reported herein. It has also been demonstrated