第32届中国化学奥林匹克初赛有机试题详解

利用框图全面归纳了第32届全国化学奥林匹克竞赛（初赛）有机试题的考点分布,并对考题进行了详细解析,以帮助致力于参加高中化学竞赛的考生取得优异成绩。     

Influence of Cavity Size on Luminescence Behavior of 8-Hydroxyquinoline in Aqueous Cyclodextrins Solution

Cyclodextrins are the hydrolyzate of starch hydrolyzed by the acid or amylase. When the numbers of glucose monomer are 6,7 and 8, the cavity size of α-, β-, and γ- cyclodextrin are 0.57nm, 0.78nm and 0.95nm.     

C_4S_4~(m-)(m=0,1,2,3,4)的从头算研究2.成键状况、电离势和振动频率

在ＲＨＦ（基离子在ＵＨＦ）／６－３１Ｇ,６－３１Ｇ＊和６－３１＋Ｇ水平用从头算和Ｂｏｙｓ定域化方法计算了Ｃ４Ｓ４ｍ－（ｍ＝０,１,２,３,４）的电子结构、电离势和定域化分子轨道。讨论了其成键特征和电离势与ΔＥＳＣＦ的关系。在６－３１Ｇ水平用ａｂｉｎｉｔｉｏ解析方法计算它们的谐振动频率。电子结构计算结果和Ｂｏｙｓ定域化分子轨道及振动分析结果与优化的平衡几何和相对稳定性相一致     

Schiff碱N-氧化吡啶-2-甲醛缩氨基硫脲的晶体结构

合成了标题Ｓｃｈｉｆｆ碱并获得了其单晶,化学式为Ｃ７Ｈ８Ｎ４ＯＳ,Ｍｒ＝ １９６．２３,经Ｘ射线单晶衍射分析,该晶体属于单斜晶系,空间群为Ｃ２／ｃ,晶胞参数： ａ＝ １３．１９８（２）,ｂ＝ ８．０７０（１）,ｃ＝ １６．９９９（２）,β＝ １０２．７６０（１０）°,Ｖ＝ １７６５．８（４）３,Ｚ＝ ８,Ｄｃ＝１．４７６ｇ／ｃｍ ３,μ＝ ０．３３０ｍ ｍ － １,Ｆ（０００）＝ ８１６,在２．４６°＜ θ＜ ２９．００°范围内以ω扫描方式收得独立衍射点２３４７ 个,其中Ｉ＞ ２σ（Ｉ）的可观测点为１６８７ 个。最终偏离因子Ｒ＝０．０３４４,ｗ Ｒ＝ ０．０８４３,（Δ／σ）ｍ ａｘ＝ ０．００１,Ｓ＝ １．０８２。分子为平面构型。与相应配合物的晶体结构进行了比较并讨论了配位前后标题化合物主要的键性质的变化。     

Thermal Behavior, Non-isothermal Decomposition Reaction Kinetics of Copper（Ⅱ） Salt of 4-Hydroxy-3,5-dinitropyridine and Its Application in Propellant

IntroductionCopper( ) salt of4- hydroxy- 3,5 - dinitropy-ridine( 4 HDNPCu) is an energetic material contain-ing energetic_ NO2 groups,which can be used asan energetic auxiliary catalyzer substituting the in-ertia copper salt to improve the catalysis of themain catalyzer( lead salt) in propellant[1] .Thermalbehavior is one of the most important aspects af-fecting its catalytic efficiency for propellant.How-ever,its kinetic parameters of thermal decomposi-tion and its application in RDX- co…     

Heterogeneous Photocatalytic Mineralization of Chlorobenzene by Paratungstate-loaded Titania Catalysts in an Aqueous Medium

Paratungstate-loaded titania catalysts were prepared via the addition of a series of aqueous solutions of paratungstate( denoted as W7 ) into an isopropanol solution of Ti[ OCH( CH3 )2 ]4 by means of the sol-gel method. The catalysts were characterized by EDX, BET, FTIR, UV-Vis DRS, XRD and the results indicate that such paratungstateloaded catalysts maintained their heptatungstate structure in the anatase titania matrix up to 400℃. The catalysts were tested for the heterogeneous photodegradation of chlorobenzene in aqueous media and showed a better catalytic activity than P-25 TiO2 because paratungstate can prevent the recombination of the holes and electrons produced during irradiation. Moreover, the paratungstate-loaded titania catalysts can resist the disaggregation during the photoirradiation and can be easily recycled from the aqueous suspensions after reactions.     

Synthesis, Characterization, Spectroscopic Properties of 2-（4-Dimethylaminophenyl）-5-fluoro-6-（morpholin-4-yl）-1H-benzimidazole and its Interaction with Calf Thymus DNA

Benzimidazole compounds have attracted a renewed interest recently owing to theirpotential applications in high-performance composite materials, electronic chemicals,photosensitive materials, and their special potentials in biological and/or medicinalapplication1,2. Typically, aromatic compounds with near planar structures and contain-ing hydrogen-donor groups or groups, which are capable of being protonated, havespecial interactions with DNA via intercalation, hydrogen-bonding, and so on3.Me…     

Theoretical Study on the Isomerization Mechanism of Enol Ester from 2-Acyl-1, 3-cyclohexanediones

The present paper employed density function theory to investigate two reaction pathways for isomerization of enol ester proposed by Yang(path a) and the present authors(path a), respectively. The base catalytic effects of solvent triethylamine on these two reactions were also evaluated. It is demonstrated that path B is more preferable than path a due to low barrier height for the rate-determining step.     

An Efficient and Green Synthesis of 5-Oxo-5, 6, 7, 8-tetrahydro- 4H-benzo-[b]-pyran Derivatives Promoted by InCl_3·4H_2O Under Microwave Irradiation

Construction of tetrahydropyran rings has attracted a great deal of interests in organic synthesis in recent years1, since tetrahydropyran moiety constitutes a structural unit in a number of natural products2. In addition, tetrahydropyran derivatives possess wide range of biological activities and pharmacological properties, such as anticancer activity3 and antihypersensitivity4. Many methods for the preparation of such compounds have already been developed5. Among them, condensation of α, β…     

FeCl_3·6H_2O Catalyzed Reaction of Aromatic Aldehydes with 5, 5-Dimethyl-1, 3-cyclohexandione in Ionic Liquids

Room temperature ionic liquids with low melting point (<100℃) salts represent a new class of non-molecular, ionic solvents. Especially those based on the 1-N-alkyl-3- methylimidazolium cations, have shown great promise as an attractive alternative to conventional solvents for catalytic reactions1. On the other hand, FeCl3·6H2O was considered to be an environmentally benign Lewis acid and has been used successfully in several kinds of organic reactions2. Recently we have focused our interes…