O-烷基S-烷基(芳基)硫代磷(膦)酸衍生物与三氯氧磷的氯化反应──合成S-烷基(芳基)硫代磷(膦)酰氯酯的新方法

在研究O,O二烷基O芳基硫代磷酸酯(1)与三氯氧磷的异构化氯化反应机理时,发现1的异构化产物O,S二烷基硫代磷酸酯(4)能顺利地与三氯氧磷反应,4中的烷氧基被氯原子取代,得到的产物S烷基硫代磷酰氯酯(2)和O烷基磷酰二氯酯3.当4中的R为烷基或苯基,R'为烷氧基、芳氧基、烷硫基、芳硫基、二烷基氨基、氮杂环基、苯基和甲基,R"为C_1-4烷基时,4的氯化反应也能顺利发生,并得到较高产率的预期产物.     

有机硫代磷(膦)酸铵盐与三氯氧磷的氯化反应──合成硫(酮)代磷(膦)酰氯的一种新的简便方法

O,O二烷基硫代磷(膦)酸衍生物与二甲胺水溶液发生去烷基反应后,生成的硫代磷(膦)酸铵盐与三氯氧磷发生氯化反应,得到硫(酮)代磷(膦)酰氯.本文还讨论了该反应可能的机理.     

O—烷基S—烷基（芳基）硫代磷（膦）酸衍生物与三氯氧磷的氯化反应

在研究Ｏ,Ｏ－二烷基Ｏ－芳基硫代磷酸酯（１）与三氯氧磷的异构化氯化反应机理时,发现１的异构化产物Ｏ,Ｓ－二烷基硫代磷酸酯（４）能顺利地与三氯氧磷反应,４中的烷氧基被氯原子取代,得到的产物Ｓ－烷基硫代磷酰氯酯（２）和Ｏ－烷基磷酰二氯酯３,当４中的Ｒ为烷基或苯基,Ｒ为烷氧基、芳氧基、烷硫基、芳硫基、１二烷基氨基、氮杂环基、苯基和甲基,Ｒ为Ｃ１－４烷基时,４的氯化反应也能顺利发生,并得到较高产率的预期产     

S-烷基-O-(2,6-二氯-4取代苯基)硫代磷(膦)酸酯的合成及杀菌活性的研究

O,O-二烷基硫酮代磷(膦)酸酯(3)与三氯氧磷发生异构化氨化反应得到S-烷基硫代磷(膦)酰氨(4),4与2,6-二氯-4-取代苯酚反应,合成了26种新的标题化合物.生物活性初步测定结果表明,这些化合物均有一定的杀菌活性.     

S-烯丙基-O-取代苯基硫代磷(膦)酸衍生物的合成及杀菌活性研究

O,O-二烯丙基硫代磷(膦)酸酯(6)与三氯氧磷发生异构化氯化反应得到S-烯丙基硫代磷(膦)酰氯7和O-烯丙基磷酰二氯酯(8).7在碱性溶液中与取代酚反应,合成了18个新的标题化合物,生物活性测试表明,这些化合物均有一定的杀菌活性,有些化合物还具有较好的杀菌活性或杀虫活性.     

有机硫代磷（膦）酸铵盐与三氯氧磷的氯化反应

Ｏ,Ｏ－二烷基硫代磷（膦）酸衍生物与二甲胺水溶液发生去烷基反应后,生成的硫代磷（膦）酸铵盐与三氯氧磷发生氯化反应,得到硫（酮）代磷（膦）酰氯,本文还讨论了该反应可能的机理。     

O,O-二烷基S-烷基(芳基)二硫代磷酸酯的异构化氯化反应——合成S-烷基S-烷基(芳基)二硫代磷酸衍生物的新方法

报道了合成S-烷基S-烷基(芳基)二硫代磷酸衍生物的一种便利的新方法。O,O-二烷基S-烷基(芳基)二硫代磷酸酯与三氯氧磷发生氯化反应的同时,伴随着P=S键异构成P-S键,生成S-烷基S-烷基(芳基)二硫代磷酰氯,在碱存在下进一步与各种亲核试剂反应,得到S-烷基S-烷基(芳基)二硫代磷酸衍生物。     

S-烷基-O-多氯苯基硫代磷(膦)酸衍生物的合成及杀菌活性研究

O,O-二烷基硫代磷(膦)酸酯与三氯氧磷发生异构化氯化反应生成S-烷基硫代磷(膦)酰氯,后者在缚酸剂存在下与多氯酚反应得到标题化合物。此类化合物也可以用传统方法,从S-烷基硫代磷酰二氯先后与多氯酚及其它亲核试剂反应得到。对所合成的28个新化合物的平碟试验表明,在0.005%浓度下对小麦赤霉等12种植物病菌均表现了明显的抑制活性。     

S—烷基—O—（2,6—二氯—4—取代苯基）硫代磷（膦）酸酯的合成及杀…

Ｏ，Ｏ－烷基硫酮代磷（膦）酸酯（３）与三氯氧磷发生异构化氯化反应得到Ｓ－烷基硫代磷（膦）酰氯（４），４与２，６－二氯－４－取代苯酚反应，合成了２６种新的标题化合物。生物活性初步测定结果表明，这些化合物均有一定的杀菌活性。     

硫代草酸异构体结构及异构化反应机理的理论研究

采用量子化学CBS-QB3组合方法对硫代草酸可能存在的异构体构型及异构体间相互转化机理进行了详细计算研究,分别得到11种稳定结构及12种异构化过渡态。其中硫代草酸异构体的相对稳定性顺序为M11M7M10M1M9M6M2M3=M4M5,不稳定异构体M5极易向稳定异构体转化。异构体M6向M11转化仅需越过1.92k J·mol-1的能垒,且放出49.04k J·mol-1能量,因此M6向M11的转化是H迁移异构化反应的主通道。     

CIONO2与O(3P)的反应机理

采用密度泛函方法Ｂ３ＬＹＰ／６－３１Ｇ＾＊研究了反应Ｏ（＾３Ｐ）＋ＣｌＯＮＯ２→ＣｌＯ＋ＮＯ３反应Ｏ（＾３Ｐ）＋ＣｌＯＮＯ２→Ｏ２＋ＣｌＯＮＯ的反应机。该结果与大部分实验者的推论是一致的,对于后一反应,其两种反应途径的活化势垒较为相近,表明两种反应途径均是可能的。     

ClONO2与O(3P)的反应机理

采用密度泛函方法Ｂ３ＬＹＰ／６－３１Ｇ研究了反应Ｏ（~（３）Ｐ）＋ＣＩＯＮＯ_２→ＣＩＯ＋ＮＯ_３和反应Ｏ（~（３）Ｐ）＋ ＣＩＯＮＯ_２→Ｏ_２＋ ＣＩＯＮＯ的反应机理．从动力学角度考察,计算结果表明,由于前一反应的活化势垒较低,因而是主要反应．该结果与大部分实验者的推论是一致的,对于后一反应,其两种反应途径的活化势垒较为相近,表明两种反应途径均是可能的．     

The Mechanism of the Wolff-Kishner Reduction,Elimination, and Isomerization Reactions

The mechanism of the Wolff-Kishner reaction is discussed in the light of accumulated information about the kinetics, thermodynamics, and solvent effects of the process. Wolff-Kishner reduction under normal conditions is thought to involve the trans hydrazone anion, which, in the rate-determining step, exhibits a more or less concerted proton capture at the carbanion terminal and undergoes a solvent-induced proton loss at the nitrogen terminal. The stereochemistry of the Wolff-Kishner reduction is believed to be affected by the presence of “ortho” substituents and by a change to a nonpolar, aprotic reaction medium. The mechanism elaborated for the Wolff-Kishner reduction is extended to the Wolff-Kishner elimination and isomerization reactions. Conformational analysis of the intermediates permits correlation of the competitive reduction and elimination processes with the structures of acyclic systems.     

Isomerization reaction of 1,1,2,2-tetrafluorethan on fluorinated chromia: A consideration of the adsorption behavior on the catalyst

Adsorption of HF is a crucial step in the course of heterogeneously catalyzed reaction of chlorocarbons with gaseous HF. Hence, the adsorption equilibrium of HF and haloalkanes involved in the isomerization reaction of 1,1,2,2-tetrafluoroethane into 1,1,1,2 tetrafluoroethane on the catalyst surface has been studied in detail. By evaluation of the measured reaction data using the partial differential equation of isomerization expanded for variant orders to take into account influence of the adsorption the reaction order of HF was found to be zero in all stages, that of trifluoroethylene decreases from 1 to 0.5 for the reaction to 1,1,1,2 tetrafluoroethane, all others remain essentially one. Based on experimentally determined adsorption isotherms, the cell theory of adsorption allowed the extrapolative calculation of the adsorption isotherms for both isomers of tetrafluoroethane, trifluoroethylene and HF for a wide range of temperature. The formation of a pre-adsorption layer of HF at the chromia surface is in agreement with the reaction order (0) for HF. From these results, conclusions were drawn regarding the reaction mechanism of the isomerization reaction of 1,1,2,2 tetrafluoroethane.     

B4O分子异构化稳定性的理论研究

采用CCSD(T)/6-311+G(2df)//B3LYP/6-311+G(d)方法, 系统研究了B₄O体系各个异构体的结构和能量, 以及重要异构体的解离和异构化稳定性. 结果表明, 单态平面三角形含-BO单元的异构体cB₃-BO ¹1能量最低, 其次是带状的异构体B₄O ¹2(10.9 kJ/mol), 并且¹1和¹2结构都具有良好的动力学稳定性. 因此对于B₄O体系, ¹1和¹2都是有可能存在的. 而文献报道的三态直线型结构BBBBO(146.0 kJ/mol)的能量比异构体¹1和¹2高得多.     

Mechanism and kinetics properties for the reaction: Chloroethane with atomic O (P)

In this paper, we present direct dynamics calculations for the multiple-channel reaction of CH₃CH₂Cl with atomic O (³P) in a wide temperature range (200–3000 K), based on canonical variational transition state theory including small curvature corrections. Four distinct saddle points, one for α-abstraction and three for β-abstraction, have been located for this reaction. The potential energy surface information has been calculated at the MP2/6-311G(d,p) level. The energies along the minimum energy path have been further improved by single-point energy calculations at the G3MP2 level. In the β-abstraction channel, Jahn–Teller effect has been found. Changes of geometries, generalized normal-mode vibrational frequencies, and potential energies along the reaction paths for all channels have been discussed and compared. The calculated total rate constants match the available experimental values reasonable well over the measured temperature range. The results show the variational effect can be negligible and the small curvature tunneling contribution plays an important role for the calculation of the rate constant. At low temperature α-abstraction may be the major reaction channel, while β-abstraction will have more contribution to the whole reaction rate as the temperature increase.