Gas Phase Reaction of Tetrachlorogermane with Conjugated Dienes in the Presence of Hexachlorodisilane Initiator

Studies of the reaction of GeCl₄ with acyclic conjugated dienes (1,3-butadiene, 2-methyl-1,3- butadiene, 2,3-dimethyl-1,3-butadiene) and cyclopentadiene in the presence of Si₂Cl₆ initiator were carried out. With acyclic dienes, corresponding 1,1-dichloro-1-germacyclo-3-pentenes and 1,1-dichloro-1-silacyclo-3- pentenes are preferrably formed. With cyclopentadiene the main reaction products are cyclopentenyltrichlorogermanes and cyclopentenyltrichlorosilanes formed respectively by hydrogermylation and hydrosilylation of the starting diene. The explanation of the established rule is offered.     

Gas-Phase Reaction of Free Diethylsilylium Ions with Hexamethyldisiloxane

The gas-phase reaction of diethylsilylium ions with hexamethyldisiloxane was studied by the radiochemical procedure. As in reactions with other nucleophiles, the degree of rearrangement of the diethylsilylium ion in the reaction with hexamethyldisiloxane correlates with the condensation energy. In contrast to the reaction of Et₂SiT⁺ with dibutyl ether, in the reaction with hexamethyldisiloxane the labeled substrate is formed, which is due to isomerization of the trimethylsilyl substituent giving rise to a labile hydrogen atom.__________Translated from Zhurnal Obshchei Khimii, Vol. 75, No. 5, 2005, pp. 751–753.Original Russian Text Copyright © 2005 by Kochina, Vrazhnov, Sinotova, Ignat’ev.     

水相中取代苯酚的硫酸氢钠/硝酸钠硝化反应

以硫酸氢钠和硝酸钠为硝化剂,在水溶液中完成了取代苯酚的硝化反应.硝化产物具有良好的选择性和较高的产率.     

硝酸根存在下冰相中苯酚的光转化

通过室内模拟实验, 采用125 W高压汞灯作为光源, 在低温条件下(-14～-12 ℃)研究了冰相中硝酸根存在下苯酚的光解. 考察了苯酚的浓度、硝酸根的浓度、pH值以及光强度等因素对冰相中苯酚光化学转化的影响. 研究结果表明, 在冰相中苯酚光转化速率随着光强度和NO₃^-初始浓度的增加而加快, 随着苯酚初始浓度的增加而减慢; 在强酸或强碱条件下均抑制苯酚的光转化速率; 苯酚的光解速率符合一级动力学模式. 利用GC-MS和LC-MS分析了苯酚的光解产物, 据此推测了苯酚在硝酸根体系中可能的光解反应历程.     

Coupling of Phenol with Ketones in the Presence of Heteropoly Acids with Different Structures and Compositions

The reactions of phenol coupling with ketones MeCOR (R = CH₃, C₂H₅, C₃H₇, and C₄H₉) are studied in the presence of heteropoly acids with different structures and compositions in toluene solutions ([PhOH]/[MeCOR] = (2–8)/1 mol/mol; 50–70°C) with thioglycolic acid added as a promoter. The reaction rate depends on ketone and heteropoly acid, and the yield of bisphenols is as high as 24–72%. The reaction orders are 0.68, 0.77, and 0.97 with respect to H₆P₂W₂₁O₇₁, H₃PW₁₂O₄₀, and H₄SiW₁₂O₄₀, respectively, and the activation energies are 25.1, 21.0, and 20.6 kcal/mol, respectively. Heteropoly acids of the Dawson structure exhibited the highest activity.     

气相反应对CVD生长石墨烯的影响

化学气相沉积法(CVD)制备的石墨烯薄膜具有质量高、均匀性好、层数可控且可放大等优点,近年来受到了学术界和工业界的广泛关注。在高温CVD生长过程中,除衬底表面的反应外,气相反应同样会影响石墨烯的生长行为和薄膜质量。本文将综述气相反应对CVD生长石墨烯的影响：首先对CVD体系内的气相传质过程和气相反应进行了详细讨论;随后系统介绍了基于气相调控提高石墨烯的结晶性、洁净度、畴区尺寸、层数和生长速度的相关策略及其机理;最后对气相反应影响CVD生长石墨烯的规律进行总结,并展望了未来可能的发展方向。     

Al+与乙硫醇团簇的气相化学反应的实验和理论研究

利用激光溅射-分子束的方法研究了Al⁺和乙硫醇的气相化学反应,结果观察到了Al⁺与1～6个乙硫醇分子形成的团簇离子. 对团簇离子进行了密度泛函理论计算,找到了两种类型的异构体Al⁺(C₂H₅SH)_n和HAl⁺SC₂H₅(C₂H₅SH)_n-1,计算得到了相应的稳定结构和能量.分析质谱信号强度,结合理论计算结果,可推测出实验得到的n=1的产物离子是Al⁺(C₂H₅SH). n=2和3时产物离子开始转变为HAl⁺SC₂H₅(C₂H₅SH)_n-1, n=4时,HAl⁺SC₂H₅(C₂H₅SH)₃和Al⁺(C₂H₅SH)₄两种产物离子都存在,n≥5以后,团簇离子Al⁺(C₂H₅SH)_n开始成为主要的产物离子.     

二丁基二月桂酸锡催化碳酸二甲酯和苯酚酯交换反应研究

研究了二丁基二月桂酸锡催化碳酸二甲酯和苯酚酯交换反应的活性和选择性,发现不同厂家生产的二丁基二月桂酸锡对该反应的催化活性和选择性差异较大,采用反应分离一体化的工艺可提高苯酚的转化率。     

Reaction of Organylchlorosilanes with Dimethyl Sulfoxide in the Presence of Octamethyltrisiloxane

Dichloro(methyl)(vinyl)silane reacts with DMSO in the presence of octamethyltrisiloxane to form cyclooligomethyl(vinyl)siloxanes(MeViSiO) _n (n = 3-6). The reaction involves disproportionation of octamethyltrisiloxane into hexamethyldisiloxane and decamethyltetrasiloxane. Along with the latter two products, insertion products of methyl vinyl silanone into both permethyloligosiloxanes were identified. Alkyltrichlorosilanes RSiCl₃ (R = Me, Et) react with DMSO in the presence of octamethyltrisiloxane to form cyclic oligoalkyltrichlorosiloxanes (RClSiO) _m (m = 3-6).     

Reaction of Some Terpenoids with Malononitrile in the Presence of Hydrotalcite

α-Ionone and 5,5,8-trimethyl-3,7-nonadien-2-one react with malononitrile in the presence of specially prepared hydrotalcite to afford the corresponding Knoevenagel condensation products with high yield and selectivity.__________Translated from Zhurnal Organicheskoi Khimii, Vol. 41, No. 6, 2005, pp. 859–863.Original Russian Text Copyright © 2005 by Khomenko, Volcho, Toktarev, Echevskii, Salakhutdinov, Barkhash.     

Complex of Tetrachlorogermane with Dimethyl Sulfoxide and Its IR Spectral Study

The complex 2(Me₂SO)-GeCl₄ in which the hexacoordinate germanium atom is coordinated via oxygen atoms with two Me₂S = O molecules was studied by IR spectroscopy. The strong doublet band with maxima at 495 and 506 cm^-1 in the spectrum of the complex was assigned to stretching vibrations of the Ge-O coordination bond. Thermolysis of 2(Me₂SO)·GeCl₄ yields, along with the consituent molecules, polyoxymethylene, dimethyl disulfide, and trace amounts of chloromethyl methyl sulfide.     

钛酸酯催化碳酸二甲酯与苯酚酯交换反应的研究

用Ti(OBu)4、Ti[OCH(CH3)2]4和T(OPh)43种钛酸酯作催化剂,对碳酸二甲酯（DMC）与苯酯的酯交换反应进行了研究。以Ti(OBu)4为催化剂,对反应的热力学、原料配比、催化剂用量、反应温度和反应时间等工艺条件进行了考察 。实验表明,当DMC：苯酚：Ti(OBu)4(摩尔比）＝1.5:1:0.05、反应温度175℃、反应时间为25h时,酯交换反应基本上达到平衡,苯酚的转化率为47.4％,MPC的选择性为90.9%,DPC的选择性为9.14%.     

乙酸存在下磷酸铁催化对甲酚气相选择性氧化

 在乙酸存在和空气气氛下,以磷酸铁为催化剂进行了对甲酚气相选择氧化生成对羟基苯甲醛和对羟基苯甲醇的反应. 考察了不同乙酸/对甲酚比和反应温度对反应产物分布的影响. 结果表明,加入乙酸可抑制目标产物深度氧化,促进气相反应中高选择性地生成对羟基苯甲醛和对羟基苯甲醇. 在反应温度为250 ℃,乙酸/对甲酚比为0.9,催化剂用量为0.35 g和对甲酚流速为1.92 g/h时,生成对羟基苯甲醛的选择性为34.4%,生成对羟基苯甲醇的选择性为65.6%.     

The Haloform Reaction in the Presence of Cyclodextrins

Cyclodextrins act as inverse phase transfer catalystsin the oxidation of methyl ketones by hypochloride(the haloform reaction). The reaction is affected by thechoice and the amount of cyclodextrin. The reactionproceeds under mild reaction conditions and itprovides only the corresponding carboxylic acid asreaction product. No organic solvent is required.     

关于苯酚和碳酸钠反应的探讨

设计一组实验,分别在一定体积的1.5 mol/L的苯酚乳浊液中加入一定量的晶体碳酸钠、不同体积的饱和碳酸钠溶液,在相同的条件下,用蒸馏水作对照,观察反应现象。结果观察到实验组苯酚乳浊液变清的现象。结论苯酚能与晶体碳酸钠或饱和碳酸钠溶液反应,生成苯酚盐,并通过平衡常数的计算从理论上进行分析和讨论。     

金属锡作用下炔丙基碘与醛类化合物的反应

金属锡作用下的烯丙基卤代物与羰基化合物的加成反应以其反应条件温和及能选择性地与含有其他反应活性基团的羰基化合物加成等特点而显示出在有机合成上的应用价值。但目前这类反应还只局限于烯丙基卤代物反应的范围内。本文首次报道金属锡作用下的炔丙