3-硝基-1,2,4-三唑-5-酮与NH3及H2O分子间相互作用的理论研究

在DFT-B3LYP/6-311＋＋G**水平上, 求得3-硝基-1,2,4-三唑-5-酮(NTO)/NH₃和NTO/H₂O两种超分子体系势能面上5种全优化构型. 经基组叠加误差(BSSE)和零点能(ZPE)校正, 求得NTO与NH₃和H₂O的分子间最大相互作用能依次为－37.58和－30.14 kJ/mol, 表明NTO与NH₃的分子间相互作用强于与H₂O的作用. 超分子体系中电子均由NH₃或H₂O向NTO转移, 相互作用能主要由强氢键所贡献, 由自然键轨道分析揭示了相互作用的本质. 对优化构型进行振动分析, 并基于统计热力学求得200.0～800.0 K温度范围从单体形成超分子的热力学性质变化. 发现由NTO和NH₃形成超分子II和III在常温下可自发进行; 而NTO和H₂O只在低温下才能自发形成IV, V和VI超分子.     

季戊四醇四硝酸酯的分子结构和热解机理

运用SCF-AM1-MO方法，在RHF和UHF水平上分别全优化计算了季戊四醇四硝酸酯(太安)的分子结构和热解机理。计算所得三种构象的能量相差很小、且相互转化的能垒也较小。其均裂O-NO~2键(生成双自由基)的热解引发反应活化能较小，而通过α-H转移产生RCHO和HONO的环消除反应需要较高活化能。     

A theoretical study on nitration mechanism of benzene and solvent effects

Aromatic nitration is an important and canonical example of electrophilic substitution in organic chemistry. The research on nitration mechanism is also very important for synthesis of explosives since benzene molecule is a basic unit to build up into the energetic material. Besides the electrophilic substitution mechanism, there is an electron transfer mechanism[1,2]. The nitronium ion (NO+ 2), however, is a generally accepted active nitrating agent in the aromatic nitration. Therefore, the …     

DFT Study of Dimethylaluminum Azide Clusters： Structures,Energies, Frequencies and Thermodynamic Properties

Introduction The organoaluminum azide compounds have been widely used in many fields. These compounds are used as the azidating agents,1-3 and the energetic materials which are always used in national defence industry and in space technology, especially to generate thin films of AlN in various chemical vapor deposition (CVD) sys-tems.4-6 Aluminum nitride has useful properties for coatings, especially for optical or optoelectronic devices, acoustic wave devices and electronic microcircuits.7 …     

Coupling Reaction of Carbonyl Compounds Mediated by Gallium Metal in Aqueous Media

A simple and effective pinacol coupling of various aromatic aldehydes mediated by gallium in good yields has been carried out. The reaction is highly effective in water in the prurience of KOH or HCl and was strongly affected by the steric environ-ment surrounding the carbonyl group. Aliphaflc aldehydes, ke-tones and aromatic ketones appear inert under the same reac-tion conditions.     

A Chiron-based Approach for the Synthesis of Tricyclic Tyrosine Analogue

A chiron approach-based enantioselective synthesis of designed tricyclic tyrosine analogue D-2 was developed. A SmI2-mediated free radical cyclization, an intramolecular Friedel-Crafts reaction and an intramolecular Mannich reaction served as key steps. These key steps were optimized and repeated in good yields. All the stereochemistries in the synthesis were established and confirmed.     

Influences of Brnsted Acidic Sites in HZSM-5 on Polarization and Electronegativity of Ethene Studied by Molecular Dynamics

ＩｎｔｒｏｄｕｃｔｉｏｎＺｅｏｌｉｔｅｓ ,ｍｉｃｒｏｐｏｒｏｕｓａｌｕｍｉｎｏｓｉｌｉｃａｌｉｔｅｓ ,ａｎｅｘｔｒａｏｒ ｄｉｎａｒｉｌｙｄｉｖｅｒｓｅａｎｄｅｘｃｉｔｉｎｇｃｌａｓｓｏｆａｄｖａｎｃｅｄｉｎｏｒｇａｎｉｃｍａｔｅｒｉａｌｓ ,ａｒｅｋｎｏｗｎｆｏｒｔｈｅｉｒｃａｔａｌｙｔｉｃａｎｄｓｈａｐｅ ｓｐｅｃｉｆｉｃｐｒｏｐｅｒｔｉｅｓｃｏｎｃｅｒｎｅｄｗｉｔｈｔｈｅｉｒｍｉｃｒｏｐｏｒｏｕｓｓｔｒｕｃｔｕｒｅｓ .Ａｄｓｏｒｐｔｉｏｎ ,ｐｏｌａｒｉｚａｔｉｏｎａｎｄｓｕｂｓｅｑｕｅｎｔｄｉ…     

四唑及其衍生物的理论研究：II.一氯代四唑负离子的从头算

用从头计算法，取６－３１Ｇ基组，在ＭＰ２水平上，计算研究了１Ｈ－和２Ｈ－四唑一氯取代物三种负离子的全优化几何构型和电子结构，比较讨论了它们的芳香性和稳定性，发现三者均取平面构型，其芳香性和稳定性次序为５－氯四唑负离子〉２－氯四唑负离子〉１－氯四唑负离子，预示了形成金属配俣物时５－氯四唑作为配体的重要性和配位方式。     

高镍含量二元金属柱撑粘土的制备

报道了一种制备多元金属柱撑粘土的新方法－生长法。将此法与通用的同晶取代法制得的样品进行比较，发现前者的镍含量远大于后者。此种交联物的底面间距约１．７ｎｍ，样品在ＩＲ谱中７４４ｃｍ＾－１处出现的吸收谱带可作为柱状物存在的标识，插入层间的柱状物中镍以六配位形式存在，是一种尖类晶石结构，处于这种状态的镍要比同晶取代进入Ｊｏｈａｎｓｓｏｎ离子中的镍更难于被还原。     

单硝基甲苯和多硝基甲苯偶极矩的理论计算和实验测定

用 MINDO/3和 CNDO/2法对单硝基甲苯和多硝基甲苯的平衡几何构型进行了全优化和 SCF 计算,求得了o,m,p-MNT,2,3-,2,4-,2,5-,2,6-,3,4-,3,5-DNT 和2,3,4-,2,3,5-,2,3,6-,2,4,5-,2,4,6-以及3,4,5-TNT 的“气相”偶极矩。用折射法实测了 MNT 和 DNT 共9种化合物在 CCl_4溶液中的偶极矩。计算值和实测值之间存在良好的线性关系。以甲苯和硝基苯的计算值通过“向量加和”近似地估算了 MNT,DNT 和 TNT的偶极矩,估算值与上述实验值和量子化学计算值之间也线性相关。