傅立叶变换拉曼光谱和红外光谱鉴别塑料

用傅立叶变换拉曼光谱、衰减全反射红外光谱和近红外光谱结合OPUS/Ident软件对添加不同填料、不同助剂的塑料进行鉴别分类。结果表明:分子光谱结合化学计量学鉴别塑料是一种快速可靠的方法。其中拉曼光谱和衰减全反射红外光谱能够直接区分样品,而近红外光谱非常类似,不能直接区分。但是用OPUS/Ident软件中的W ard算法处理这3种光谱后,得到的树形图能够将样品准确分类。     

广义二维相关光谱在红外和拉曼光谱研究中的应用

介绍广义二维相关分析方法 ,给出了二维相关光谱的广义数学公式及其推广过程。阐述了广义二维相关光谱的基本性质。给出了二维相关在傅立叶变换拉曼和近红外的应用实例 ,以证明广义二维相关光谱在结构分析以及相关性方面的独特效用。     

拉曼光谱在分析化学中的应用进展

评述了各种拉曼技术在分析化学方面的应用进展,涉及到的拉曼光谱技术有常规拉曼光谱、常规共振拉曼光谱、表面增强拉曼光谱、表面增强共振拉曼光谱、傅里叶变换拉曼光谱、傅里叶变换表面增强拉曼光谱及其联用技术。共引用９１篇文献。     

表面增强拉曼技术及FT-拉曼的研究及应用

本文综述了拉曼光谱分析法的建立与发展、表面增强拉曼光谱（ＳＥＲＳ）法及傅立叶变换拉曼光谱（ＦＴＲａｍａｎ）法的应用进展。     

用于电化学界面研究的共焦显微拉曼光谱技术(英文)

系统地介绍了将共焦显微拉曼光谱系统用于电化学界面研究的方法 ,包括铂电极的粗糙和电化学拉曼电解池的设计 .进行了铂上氢、氧和氯共吸附的拉曼光谱研究 .通过对甲醇氧化过程的现场跟踪 ,提出检测界面区溶液浓度变化和计算溶液 pH值的方法 .实验表明拉曼光谱技术可作为研究实际应用体系的重要工具 .     

基于显微共聚焦拉曼光谱技术快速检测3种梭菌中肉毒梭菌

提出了一种基于显微共聚焦拉曼光谱技术的肉毒梭菌快速鉴别方法.利用共聚焦显微拉曼光谱技术(CRM)采集了肉毒梭菌、艰难梭菌和产气荚膜梭菌的拉曼光谱,比较了3种梭菌的平均拉曼光谱,采用基线校正、标准正态变换、Savitzky-Golay 5点平滑和最大最小值归一化预处理后,借助主成分分析(PCA)降维并提取特征变量,对样本...     

C_(60)离子束撞击固体表面的坍塌沉积(Ⅰ)共焦显微拉曼光谱研究

为了研究C60的结构特性，我们最近在实验中将加这后的C60离子束沉积在固体表面，对其沉积后的形态进行了共焦显微拉曼光谱的表征．在记录的光谱中已检测不出C60原有的特征谱问，说明C60离子在高速憧击固体表面后，已经完全失去了原有的球状构型．C60的t）［R实验在自制的串级飞     

激光拉曼光谱在高分子中的应用

论述了激光拉曼光谱对高分子结构、结晶形态和表征,反应动力学过程和取向的研究,还介绍了纵向声学模、共振、高温高压、光波导和付里叶拉曼光谱在高分子研究中的最新进展。     

显微拉曼光谱用于研究大气单颗粒表面非均相反应

大气单颗粒表面的非均相反应研究因更接近大气实际条件,避免了堆积态研究中人为引入的误差,能够得到真实的反应过程与机理,获得反映大气实际条件的动力学参数.本研究建立了使用显微拉曼光谱研究大气单颗粒非均相反应的研究方法,并初步用于研究NO2与单颗粒CaCO3的非均相反应.研究结果表明显微拉曼光谱可同时获得颗粒物的化学组成和形貌变化,并能得到化学环境如相态的信息,对于研究反应过程很有帮助;而颗粒物沉降在基质上得到的拉曼光谱因不受形貌共振影响,有利于获得高质量的光谱.此外,将拉曼光谱研究单颗粒的方法与其他单颗粒非均相反应的研究方法进行了综合比较,表明显微拉曼光谱技术在单颗粒非均相反应研究中具有重要的特点和应用价值.     

氮气笼型水合物的激光拉曼光谱

在253K和16MPa的压力下,于实验室内合成了氮气水合物,用显微共焦拉曼光谱对其N-N和O-H键伸缩振动的光谱特征进行了研究．结果表明,氮气水合物中的N-N和O—H键的拉曼峰分别为2322．4和3092．1cm^-1,与天然的空气水合物中的数据十分接近．另外,还测定了液氮和溶解于水中的氮分子中N—N键的拉曼峰值,分别为2326．6和2325．0cm^-1．氮气笼型水合物分解的拉曼谱图表明,氮分子同时进入水合物的大笼和小笼中,但由于氮分子在大、小笼中的环境氛围十分接近,其拉曼位移相差不大,故拉曼谱图只能显示N—N键伸缩振动一个峰．     

Fluorometric monitoring of organic reactions on solid phase

The direct monitoring of reaction progress on solid supports by fluorescence spectroscopy is described. An immobilized fluorescent tracer molecule (dansyl chloride) is used to monitor the reaction on OH resins (Argopore Wang, PS Wang, and Argogel Wang), both in batch and in parallel chemistry. Fluorescence measurements were obtained directly on solid phase. The method demonstrated to be a valuable tool for the quantitative determination of resin-bound hydroxyl groups, to study reaction kinetics and for continuously monitoring the progress of the conversion of the hydroxyl resins into the chlorinated ones. The procedure proposed is highly sensitive compared to the traditional ones. The system can be extended to monitor a variety of reactions on solid supports, and in conjunction with a well-established technique such as flow analysis, basic studies on solid-phase become possible.     

Organic Chemistry on Solid Supports

Until recently, repetitive solid-phase synthesis procedures were used predominantly for the preparation of oligomers such as peptides, oligosaccharides, peptoids, oligocarbamates, peptide vinylogues, oligomers of pyrrolin-4-one, peptide phosphates, and peptide nucleic acids. However, the oligomers thus produced have a limited range of possible backbone structures due to the restricted number of building blocks and synthetic techniques available. Biologically active compounds of this type are generally not suitable as therapeutic agents but can serve as lead structures for optimization. “Combinatorial organic synthesis” has been developed with the aim of obtaining low molecular weight compounds by pathways other than those of oligomer synthesis. This concept was first described in 1971 by Ugi.^[56f,g,59c] Combinatorial synthesis offers new strategies for preparing diverse molecules, which can then be screened to provide lead structures. Combinatorial chemistry is compatible with both solution-phase and solid-phase synthesis. Moreover, this approach is conducive to automation, as proven by recent successes in the synthesis of peptide libraries. These developments have led to a renaissance in solid-phase organic synthesis (SPOS), which has been in use since the 1970s. Fully automated combinatorial chemistry relies not only on the testing and optimization of known chemical reactions on solid supports, but also on the development of highly efficient techniques for simultaneous multiple syntheses. Almost all of the standard reactions in organic chemistry can be carried out using suitable supports, anchors, and protecting groups with all the advantages of solid-phase synthesis, which until now have been exploited only sporadically by synthetic organic chemists. Among the reported organic reactions developed on solid supports are Diels–Alder reactions, 1,3-dipolar cycloadditions, Wittig and Wittig–Horner reactions, Michael additions, oxidations, reductions, and Pd-catalyzed C? C bond formation. In this article we present a comprehensive review of the previously published solid-phase syntheses of nonpeptidic organic compounds.     

Out of the oil bath and into the oven--microwave-assisted combinatorial chemistry heats up

The application of microwave irradiation to expedite solid-phase organic reactions could be the tool that allows combinatorial chemistry to deliver on its promise--providing rapid access to large collections of diverse small molecules. Herein, several different approaches to microwave (MW)-assisted solid-phase reactions and library synthesis are introduced, including the use of solid-supported reagents, multicomponent coupling reactions, solvent-free parallel library synthesis, and spatially addressable library synthesis on planar solid supports. The future impact of MW-assisted organic reactions on solid-phase and combinatorial chemistry could prove to be immense, and methods for further improvement of this strategic combination of technologies are highlighted.     

Pyrrolo[3,2-e][1,4]diazepin-2-one synthesis: a head-to-head comparison of soluble versus insoluble supports

Aryldiazepin-2-ones are known as "privileged structures", because they bind to multiple receptor types with high affinity. Toward the development of a novel class of aryldiazepin-2-one scaffolds, the synthesis of pyrrolo[3,2-e][1,4]diazepin-2-ones on a support was explored starting from N-(PhF)-4-hydroxyproline and featuring an acid-catalyzed Pictet-Spengler reaction to form the diazepine ring. Three supports [Wang resin, tetraarylphosphonium (TAP) soluble support, and Merrifield resin] were examined in the synthesis of the heterocycle and exhibited different advantages and disadvantages. Wang resin proved effective for exploratory optimization of the synthesis by identification of intermediates after resin cleavage under mild conditions; however, the acidic conditions of the Pictet-Spengler reaction caused premature loss of resin-bound material. Direct monitoring of reactions by TLC, RP-HPLC-MS, and in certain cases NMR spectroscopy was possible with the TAP support, which facilitated purification of intermediates by precipitation; however, incomplete precipitation of material led to overall yields lower than those from solid-phase approaches on resin. Merrifield resin proved stable to the conditions for the synthesis of the pyrrolo[3,2-e][1,4]diazepin-2-one targets and would be amenable to "split-and-mix" chemistry; however, relatively harsh conditions were necessary for final product cleavage. Perspective for the application of different solid-phase approaches in heterocycle library synthesis was thus obtained by demonstration of the respective utility of the three supports for preparation of pyrrolo[3,2-e][1,4]diazepin-2-one.     

Solid-phase construction: high efficiency dendrimer synthesis using AB3 isocyanate-type monomers

Solid-phase synthesis is an ideal tool for reactions that require high concentrations and excess reagents and forcing chemical conditions. One such chemistry is that required for dendrimer construction. In this paper the synthesis of a series of symmetrical AB₃ isocyanate-type monomers is reported and used for the preparation of tri-branched dendrimers on the solid-phase. This method not only allows isolable dendrimer but can generate high-loading supports and devices for multivalent presentation.     

Onium salt supported peptide synthesis

Task specific ionic liquids and onium salts have been used as soluble supports for peptide synthesis. These new supports combine easy monitoring, high loading capacities, large scale preparation, and homogeneous kinetics characteristics while keeping advantages of solid-phase synthesis including easy purification and workup. Careful structural design of these supports allowed for fine tuning of physical properties leading to better yields, kinetics, and purities.     

Modern separation techniques for the efficient workup in organic synthesis

The shift of paradigm in combinatorial chemistry, from large compound libraries (of mixtures) on a small scale towards defined compound libraries where each compound is prepared in an individual well, has stimulated the search for alternative separation approaches. The key to a rapid and efficient synthesis is not only the parallel arrangement of reactions, but simple work-up procedures so as to circumvent time-consuming and laborious purification steps. During the initial development stages of combinatorial synthesis it was believed that rational synthesis of individual compounds could only be achieved by solid-phase strategies. However, there are a number of problems in solid-phase chemistry: most notably there is the need for a suitable linker unit, the limitation of the reaction conditions to certain solvents and reagents, and the heterogeneous reaction conditions. Further disadvantages are: the moderate loading capacities of the polymeric support and the limited stability of the solid support. In the last few years several new separation techniques have been developed. Depending on the chemical problem or the class of compounds to be prepared, one can choose from a whole array of different approaches. Most of these modern separation approaches rely on solution-phase chemistry, even though some of them use solid-phase resins as tools (for example, as scavengers). Several of these separation techniques are based on liquid-liquid phase separation, including ionic liquids, fluorous phases, and supercritical solvents. Besides being benign with respect to their environmental aspects, they also show a number of advantages with respect to the work-up procedures of organic reactions as well as simplicity in the isolation of products. Another set of separation strategies involves polymeric supports (for example, as scavengers or for cyclative cleavage), either as solid phases or as soluble polymeric supports. In contrast to solid-phase resins, soluble polymeric supports allow reactions to be performed under homogeneous conditions, which can be an important factor in catalysis. At the same time, a whole set of techniques has been developed for the separation of these soluble polymeric supports from small target molecules. Finally, miscellaneous separation techniques, such as phase-switchable tags for precipitation by chemical modification or magnetic beads, can accelerate the separation of compounds in a parallel format.     

树状大分子在有机合成中的应用

近20年来树状大分子由于其特殊的结构而引起了科学家们的广泛关注;作为一类新型的高负载量载体应用于有机合成和催化是树状大分子重要的应用领域之一。本文主要介绍树状大分子和树脂固载树状大分子两类载体,重点对它们作为高负载量载体在有机合成和非均相催化反应中的应用研究进行了总结。     

树状大分子在有机合成中的应用

近20年来树状大分子由于其特殊的结构而引起了科学家们的广泛关注;作为一类新型的高负载量载体应用于有机合成和催化是树状大分子重要的应用领域之一。本文主要介绍树状大分子和树脂固载树状大分子两类载体,重点对它们作为高负载量载体在有机合成和非均相催化反应中的应用研究进行了总结。     

Recent advances in liquid-phase combinatorial chemistry

In combination with high throughput screening, combinatorial organic synthesis of large numbers of pharmaceutically interesting compounds may revolutionize the drug discovery process. Although combinatorial organic synthesis on solid supports is a useful approach, several groups are focusing their research efforts on liquid-phase combinatorial synthesis by the use of soluble polymer supports to generate libraries. This macromolecular carrier, in contrast to an insoluble matrix, is soluble in most organic solvents and has a strong tendency for precipitation in particular solvents. Liquid-phase combinatorial synthesis is a unique approach since homogeneous reaction conditions can be applied, but product purification similar to the solid-phase method can be carried out by simple filtration and washing. This method combines the positive aspects of classical solution-phase chemistry and solid-phase synthesis. This review examines the recent applications (1995-1999) of soluble polymer supports in the synthesis of combinatorial libraries.