Formation of Tertiary 3-Nitro Allylic Alcohol by Condensation of 2-Chloroiso- butyrophenone with Nitromethanide Anion: Estimation of Gibbs Free Enthalpies of Reaction in Solution for the Reaction Mechanism [1]

Summary. The reaction of 2-chloroisobutyrophenones and nitromethanide anion gives stereoselectively (E)-3-nitro allylic alcohols. The Gibbs free enthalpies of reaction in DMSO for carbanion addition, epoxide formation, and rearrangement to 3-nitro allylic alcohol, as elementary steps for the reaction, were estimated from corresponding neutral gas reactions and using a thermodynamical approach to the transfer of gaseous compounds to DMSO. A criterion for assigning the sign of affinity of liquid compounds to DMSO was developed on the basis of the Gibbs enthalpies of liquefaction. The information obtained on reaction rate and thermodynamic viability of the steps indicates that carbanion addition is the rate-determining step.In memory of Prof. Dr. M. Ballester, deceased on April 6, 2005     

含叔胺基功能性单体的聚合研究——ⅩⅤⅠ.含吗啉基聚丙烯酸酯类及其水凝胶的温度敏感性

我们曾报道过含吗啉基丙烯酰类单体在过氧化物或芳酮存在下的热聚合及光聚合,以及做为氧化-还原引发体系组分引发烯类单体聚合的研究。利用这类单体与过硫酸盐所构成的引发体系可以获得分子量达千万的聚丙烯酰胺。实验中还发现某些含吗啉基的丙烯酸酯类聚合物的水溶液及其水凝胶具有温度敏感性。本文合成了以下四种含吗啉基丙烯酸酯类单体:     

Photoelectrochemical behavior of coupled SnO2|CdSe nanocrystalline semiconductor films

A photoelectrochemical cell with a coupled SnO₂|CdSe nanocrystalline semiconductor electrode has been prepared by sequential deposition of SnO₂ and CdSe films onto an optically transparent electrode (OTE), and its photoelectrochemical behavior has been studied. The results show that the coupling of CdSe with SnO₂ leads to an improvement in the performance of OTE|SnO₂|CdSe over OTE|CdSe cells in terms of increased incident photon-to-current conversion efficiency, increased stability and smaller reversal of current. The favorable positioning of the energy bands of SnO₂ and CdSe is responsible for the above observations. Various photoelectrochemical parameters of the OTE|SnO₂|CdSe cell obtained for an incident light power of 0.31 mW cm⁻² at 470nm, are as follows: I_sc ≈ 25–30 μA cm⁻², V_oc ≈ 0.5–0.6 V, ƒƒ = 0.47 and a power conversion efficiency of about 2.25%.     

Fe_3(CO)_9(μ_3-S)_2的P(SR)Cl_2和P(SR′)_3取代物的合成和结构研究

用P(SR)Cl_2和P(SR′)_3作n-酸配体,分别与Fe_3(CO)_9(μ_3-S)_2进行取代反应,得到6种新的一取代产物Fe_3(CO)_8(μ_3-S)_2L和3种新的二取代产物Fe_3(CO)_7(μ_3-S)_2L_2,并对它们进行了IR、~1H NMR和MS表征,测定了其中一种取代物Fe_3(CO)_8(μ_3-S)_2[P(SC_6H_5)Cl_2]的分子和晶体结构。     

2，2＇－偶氮二异丁酸二甲酯的合成及其热分解反应的研究

本文研究了２，２＇－偶氮二异丁酸二甲酯的合成及其在甲苯、二甲苯中的热分解反应动力学，得到了其热分解反应速度常数与反应温度的关系式：Ｋ＿ｄ＝１．６３×１００￣（－１４）ｅｘｐ（－１２３．３ＫＪ／ＲＴ）２，２＇－偶氮二异丁酸二甲酯作为苯乙烯自由基聚合的引发剂，其单体转化率随引发剂用量的增加而增高，产物分子量则随之下降；引发剂用量在５％以上时，可得到分子量低于１０￣３的含有酯基端基的聚合物。     

Reaction of hexafluoropropylene and its oligomers with acetone oxime

Reactions of perfluoropropylene and its oligomers with acetone oxime in the presence of a base afford perfluoroalkyl and/or perfluoroalkenyl ethers of acetone oxime. When heated to 100 °C, the 3-perfluoro-2-methyl-2-pentenyl ether of acetone oxime (3) is quantitatively converted to 4-hydroxy-3-methyl-5,5-bistrifluoromethyl-4-pentafluoroethyl-1-pyrroline (4), the structure of which was established by X-ray diffraction analysis. A convenient one-stage synthesis of perfluoro-3-isopropyl-4-methyl-3-penten-2-one (7) was proposed.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1068–1072, June, 1994.     

K对Mn—Co—O的结构及氧化活性的影响

利用XRD,TPD,TFD-MS及催化氧化反应等实验技术,研究了K对Mn-Co-O的结构及氧化活性的影响。XRD结果表明,Mn-Co-O系已形成反尖晶石型的MnCo_2O_4结构;K-Mn-Co-O系中除MnCo_2O_4型结构外,还有新相KMnO_2存在。根据O_2的TPD-MS及吡啶的TPD结果,Mn-Co-O中添加适量的K能提高供氧活性和增加供氧数目,但酸中心数目减少,强度降低。K对Mn-Co—O催化剂氧化活性的影响随反应物分子结构的不同而异,对乙酸乙脂、苯甲酰氯等极性有机物的完全氧化反应,K能提高氧化活性,但对苯、正己烷等非极性有机物的完全氧化反应,K使其活性降低。     

Thermodynamics of mixed electrolyte solutions. XI. An isopiestic study of the quaternary system NaCl−KCl−CaCl2−H2O at 25°C

Osmotic and activity coefficients in the aqueous quaternary system sodium chloride-potassium chloride-calcium chloride were derived from isopiestic measurements at 25°C. The isopiestic data were treated by the various procedures of Scatchard, Friedman, and Reilly, Wood, and Robinson. The results obtained showed good agreement with those obtained by pseudo-ternary transforms. Interaction parameters obtained indicated the preponderance of pairwise interactions. Excess Gibbs free energies of mixing were calculated.     

Asymmetric Reductive Alkylation of Alanylproline by the Ethyl Esters of 4-Substituted 2-Oxobutenoic Acids

A method was developed for the synthesis of N-[1-(S)-(ethoxycarbonyl)-3-phenylpropyl]alanylproline (enalapril) by reductive alkylation of alanylproline with ethyl 2-oxo-4-phenylbutenoate under the conditions of hydrogenation in the presence of palladium black and 1.6% Pd/C. The yield of enalapril amounted to 65%. With the ethyl ester of the -oxo acid the diastereoselectivity of formation of the S,S,S-diastereomer was higher than with the saturated synthon. It is assumed that with ethyl 2-oxo-4-phenylbutenoate as synthon a conformationally restricted surface complex is formed between the unsaturated synthon and the active centers of the catalyst. During reductive alkylation of alanylproline by ethyl 2-oxo-4-(2-thienyl)butenoate poisoning of the catalyst occurs.     

The effective use of substituted benzoic anhydrides for the synthesis of carboxamides

Various carboxamides are synthesized from the corresponding carboxylic acids and amines with high product-selectivities using 2-methyl-6-nitrobenzoic or 2,4,6-trichlorobenzoic anhydride in the presence of 4-(dimethylamino)pyridine.