几何异构

Write the structural formula for an alkyne hydrocarbon having the fewest number of C's, which has geometric isomers, and give the IUPAC name for both geometric isomers.

答：写出有几何异构体的，含碳原子数最少的炔烃的结构式，并对所有的异构体用IUPAC命名法命名

Configurational isomerism is then due to the presence in the molecule of one or more dissymmetric centres ,in the simplest case asymmetric carbon atoms ,each of which can have and absolute configuration; and ,or ,to the presence of double blonds which can give cis- and trans-geometrical isomers .

构型异构是由于分子中存在一个或一个以上的不对称中心，在最简单的情况下是不对称碳原子，每个不对称碳原子的绝对构型是和；或者，如果存在双键的话，那么将给出顺式和反式几何异构体。

Molecular structures of fourteen 6-thioxanthine tautomers were calculated by the B3LYP/6-311G** method, both in gas and aqueous phases, with full geometry optimization. The Onsager solvate theory model was employed for aqueous solution calculations.

在密度泛函B3LYP/6-311G**水平下，对14种气相和水相中可能存在的6-硫代黄嘌呤异构体进行了几何构型的全自由度优化，并计算出它们的总能量、焓、熵、吉布斯自由能。

In this thesis,the AM1,MNDO,MINDO/3(mainly AM1)and INDO/S-CI semiempirical MO methods were used toinvestigate the excited-state intramolecular protontransfer reactions of salicylic acid derivatives—salicylic acid,methyl salicylate,salicylaldehyde,o-hydroxyaceto-phenone,salicylamide and 3-hydroxy-picolinamide (6 conformers and 2-3 anion species);2-(2'-hydroxy-5' methylphenyl) benzotriazole(4 conformers),2-(2' hydroxyphenyl) benzimidazole (3 conformers and 3anion species),Bis-2,5-(2-benzoxazolyl)hydroquinone(3 conformers),2-(2'-hydroxyphenyl)benzothiazole(2conformers) and 7-azaindole dimer (2 conformers).Theinvestigations were described as follows.Geometry optimization,relative stability andhydrogen bonding energy First,for sylicylic acid derivative molecules,the AM1,MNDO and MINDO/3 methods were used toinvestigate ground-state geometry optimization,energies,relative stabilities and hydrogen-bondingenergies on the five kinds of the molecules(designing 6 conformers and 2-3 anion species).Comparing with experimental data,the optimizedgeometry,the order of stability,the hydrogen-bonding energies and the distances between O-O in O-H..O hydrogen bonds by AM1 method were in agreementwith the experimental data,however,the C-C bondlengths optimized by MNDO and MINDO/3 were longer,C-O and O-H bond lengths were shorter;for C-N bondlengths,the results opitimized by MNDO method werethe same as those by AM1 method,nevertheless the C-Nbond lengths given by MINDO/3 method were muchshorter.For some sylicylic acid derivatives(e.g.methyl salicylate,salicylamide),the order ofstabilities on the conformers given by MNDO andMINDO/3 methods were not in agreement with theexisting conformers deduced by experimental methods,and the hydrogen bonding energies calculated by MNDO.and MINDO/3 methods were smaller.Second,the studyon the other systems found that the optimizedgeometry of the proton-transfered product with INDOmethod could not be obtained,only could theoptimized geometry of reactant be obtained,and thecalculated hydrogen bonding energies were greater.Many results of calculation indicated that the studyon the excited-state intramolecular proton transferreaction system using AM1 method was suitable andreliable.

本论文用AM1、MNDO、MINDO/3（主要是AM1）和INDO/S-CI半经验分子轨道方法对水杨酸衍生物系列——水杨酸、水杨酸甲酯、水杨醛、O-羟基乙酰苯酮、水杨酰胺和3-羟基吡啶酰胺（6种异构体和2-3种阴离子）；2-（2'-羟基-5'-甲基苯基）苯并三〓唑（4种异构体）；2-（2'-羟基苯基）苯并咪唑（3种异构体和3种阴离子）；2，5-二间氮杂氧茚氢醌（3种异构体）；2-（2'-羟基苯基）间〓杂硫茚（2种异构体）和7-〓吲哚二体（2种异构体）的激发态分子内质子转移反应在以下几个方面进行了较系统的理论研究：几何构型优化和相对稳定性及氢键能首先以水杨酸衍生物系列分子为例，用AM1、MNDO和MINDO/3方法考察了5种分子（每种分子设计6种异构体和2-3种阴离子）的基态几何构型优化，能量、相对稳定性和氢键能计算，通过和实验数据进行比较，AM1方法给出的优化几何构型、稳定性次序、氢键能和O—H。。。O氢键的0—0距离与实验数据吻合最好，MNDO和MINDO/3方法优化的C-C键长偏长，C-O键和O-H键长偏短；对于C-N键长，MNDO和AM1优化结果差别不大，而MINDO/3给出了过短的C-N键长，MNDO和MINDO/3方法给出的有些水杨酸衍生物分子（如水杨酸甲酯和水杨酰胺）异构体的稳定性次序和实验上推测的可存在异构体结果不一致，MNDO和MINDO/3方法给出的氢键能偏低，对其他体系的研究发现INDO方法常常不能得到质子转移产物的优化几何构型，只能得到反应物的优化构型，并且估算的氢键能偏高，大量的计算结果表明AM1方法对本论文研究的激发态分子内质子转移反应体系是适宜和可靠的。

A rearrangement model for the complex and its isomers of the2+ was proposed, in which there could be two competed steric courses with the trigonal bipyramidal intermediate or intermediates.

利用[Co(3，3-tri)Cl]2+体系配合物及其异构体结构模型提出了一个2+型的配合物及其几何异构体相互转换所遵循的重排机理模型。认为在该类型配合物异构体转化过程中同时存在两个竞争途径，其中间过渡态或中间体分别为三角双锥或四角锥形式。

The generating results of our system were compared with the published,results of DENDRAL and SEMAMI systems, and they were consistent with eachother.

目前本系统对于含C、N、P、S与Si等元素由于不对称中心、不对称轴引起的立体异构和几何异构均能进行穷举生成。

Then on the base of photoisomerization of azobenzene molecules,we get thelong-rang order hexagonal symmetry and rectangular symmetry microstructures in theazobenzene polymer film(2μm),induced by optical lattices.

在此基础上，根据偶氮分子的光致几何异构的特性，在偶氮苯有机聚合物薄膜(2μm)中得到了长程有序的六角对称微结构和矩形微结构。

It is found that the stereochemistry of the reactions of telluronium allylide,crotonylide and trimethylsilyallylide with α,β-unsaturated esters and amides can be tuned by thechoice of reaction conditions.

利用反应条件的变化首次实现了烯丙基、巴豆基、含硅烯丙基碲叶立德与α，β-不饱和酯、酰胺进行环丙烷反应的立体化学调控，能高立体选择性地、高效率地合成两种不同几何异构体中的一个。

According to the geometries of the conformers and the statistical weight parameters, we can construct six-state statistical weight matrices.

在此基础上，应用计算得到的模型分子的几何构型与统计权重参数，分别构建针对－CH2-和－CCl2-中心的聚偏二氯乙烯的6态旋转异构态模型。

Rresults from those studies can be summariazed as follow:(1) A preliminary study no correlationship between the UV-VIS reflection spectrum of tomato fruit surface and the lycopene amount of tomato fruit was undertaken. Based on observation from this study, a damage-free and in-situ detection technique of lycopene amount from tomato was developed with UV-VIS reflection spectroscopy;(2) The geometrical isomers of lycopene were separated successfully on C30-HPLC-PDA-ELSD. The absorption coefficients of Z-isomers were consequently dedermined. The geometrical isomer composition of lycopene could therefore be assessed. Those efforts formed a solid base to identify the natural product from synthetic compound of lycopene;(3) Lycopene resource from the fruit of Autumn oliver was proved to be available for industrial application. An extraction methos of lycopene from the fruit of Autumn oliver by supercritical carbon dioxide was developed at laboratory scale;(4) A method to extract lycopene by supercritical liquid with improved efficiency was developed; Data from this investigation suggested that a proper raw material pre-extraction process was important for a better extraction efficiency;(5) Variation in the geometrical isomer composition of lycopene during its metabolish in rat was assessed. A large amount of Z-isomers were observed. This variation took place in serum;(6) The absorption rate and accumulation in serum of natural lycopene in rat were assessed;(7) Ability to quench singlet oxygen by different geometrical isomers of lycopene was compared;(8) It was detected that whether natural lycopene had functions to regule blood-lipids and LDL antioxidation;(9) A C31 degradation piece of lycopene was found in the prostate gland of rat.

研究结果包括：[1]应用UV-VIS反射光谱法建立了番茄果实中番茄红素含量的无损伤、现场检测技术；[2]应用C30-HPLC-PDA-ELSD技术实现了对番茄红素几何异构体的分离，测定了不同顺式异构体的吸光系数，建立了天然番茄红素几何异构体组成的检测方法，为区分和鉴定人工合成品和天然产物奠定了基础；[3]证实了秋橄榄果实中的番茄红素资源具有工业开发价值，并建立了超临界CO_2萃取的实验室方法；[4]探索了提高番茄红素超临界流体萃取效率的方法，证明了物料前处理对提高萃取效率起了极其重要的作用；[5]观察了番茄红素在大鼠体内几何异构体组成的变化情况，发现了大量顺式异构体的存在，并证实了几何异构体组成在血清中发生了显著变化；[6]测定了天然番茄红素在大鼠体内的吸收率和在大鼠血清中的动态积累规律；[7]比较了不同番茄红素几何异构体淬灭单线态氧的能力；[8]检测了天然番茄红素是否具有调节血脂作用和抗低密度脂蛋白氧化的功能；[9]首次发现大鼠前列腺内存在番茄红素C31降解片段，并证实其仍具有淬灭单线态氧的能力。

It has been put forward that there exists single Ball point and double Ball points on the symmetrical connecting-rod curves of equilateral mechanisms.

从鲍尔点的形成原理出发，分析对称连杆曲线上鲍尔点的产生条件，提出等边机构的对称连杆曲线上有单鲍尔点和双鲍尔点。

The factory affiliated to the Group primarily manufactures multiple-purpose pincers, baking kits, knives, scissors, kitchenware, gardening tools and beauty care kits as well as other hardware tools, the annual production value of which reaches US$ 30 million dollars.

集团所属工厂主要生产多用钳、烤具、刀具、剪刀、厨具、花园工具、美容套等五金产品，年生产总值3000万美元，产品价廉物美、选料上乘、质量保证，深受国内外客户的青睐