虎眼万年青单萜内酯新成分的分离及结构鉴定

对虎眼万年青氯仿提取物进行柱层析分离,得到一种单萜内酯(Loliolide)化合物(6-羟基-4,4,7 a-三甲基-5,6,7,7 a-四氢-4H-苯并呋喃-2-酮),用红外光谱和核磁共振波谱确定了该化合物的结构,并用电喷雾多级串联质谱对化合物的裂解机理进行了研究.通过比旋光度和核磁共振氢谱确定了化合物的立体构型.     

1,3-偶极环加成法合成异噁唑啉新化合物及其生物活性的研究

以N-甲羟胺硫酸盐和芳香族羰基化合物为主要原料合成了一系列不同的1,3-偶极化合物, 并合成了四种不同的单取代苯乙烯. 以该系列1,3-偶极化合物和单取代苯乙烯为主要中间体, 采用1,3-偶极环加成反应合成了一系列异噁唑啉类新化合物. 同时研究了1,3-偶极化合物与单取代烯发生的1,3-偶极环加成反应, 该合成过程为理想的绿色反应, 合成产物是5位取代异噁唑啉. 通过质谱和核磁共振等表征了化合物的化学结构. 同时对系列异噁唑啉类新化合物进行了实验室内植物生物活性的测试, 发现了对植物灰霉病有效的新化合物.     

水峰调制下的3,4-Seco-olean-11,13-dien-4,15α,22β,24-tetraol-3-oic Acid的NMR结构解析

对海南半红树植物黄槿(Hibiscus tiliaceus)内生菌中提取的一个新化合物进行核磁共振结构解析的研究. 在核磁共振测试时发现水峰信号与部分样品信号发生了重叠, 直接影响了该化合物谱图数据的分析. 本工作通过实验确证了在氘代二甲亚砜(DMSO-d₆)溶剂中水峰化学位移与含水量之间的变化规律. 依据该规律, 利用定量加入纯水的方法对实际样品中的水峰信号进行了调制, 解决了水峰信号与样品信号的重叠问题, 得到了较理想的¹H NMR, ¹³C NMR一维谱和COSY, HMQC, HMBC等二维谱. 利用核磁共振提供的信息完成了对新化合物结构的解析, 确定该化合物为齐墩果烷三萜类化合物3,4-seco-olean-11,13-dien-4,15α,22β,24-tetraol-3-oic acid.     

基于C_(60)富勒烯部花菁的合成及其变色性

设计和合成了一种新的基于C_(60)富勒烯部花化合物2，用质谱、核磁共振谱 、红外光谱和紫外光谱对化合物2进行了表征。并对化合物2的变色过程进行了研究 ，发现该化合物对极性溶剂如甲醇、N,N-二甲基甲酰胺和酸或碱如乙酸、乙醇钠等 具有良好的变色过程。但由于部花莆染料受C_(60)的影响，基对光的灵敏度降低， 光致变色过程非常缓慢。     

二咔唑四苯乙烯多功能发光化合物的合成与性能

合成了一种新型的具有压致荧光变色效应的聚集诱导增强发光(PAIE)化合物二咔唑四苯乙烯; 通过核磁共振、质谱和元素分析等手段对其进行了结构表征; 利用紫外吸收光谱、荧光发射光谱、热分析和X射线衍射等手段研究了化合物的基本性能. 实验结果表明, 随着水含量的增加, 该化合物溶液荧光强度增强了171倍, 荧光量子产率提高了100倍, 表现出明显的聚集诱导增强发光效应; 在外界因素作用下该化合物固体样品可实现结晶态与无定形态的相互转变. 结晶态的荧光发射波长为450 nm, 无定形态为480 nm, 相差30 nm, 说明该化合物具有明显的压致荧光变色效应; 将该化合物用于制备发光器件, 未经优化的器件亮度达2438 cd/m², 电流效率为2.87 cd/A, 流明效率为1.81 lm/W. 该化合物是一种多功能材料.     

螺[二苯并[a,j]氧杂蒽-14,9’-芴]的合成及性质简

芴酮与2-萘酚在硫酸和3-巯基丙酸的作用下反应得到化合物螺[二苯并[a,j]氧杂蒽-14,9’-芴]. 采用核磁共振、质谱、红外光谱和元素分析等对该化合物进行了表征,并通过X射线衍射法测得了其晶体结构,确定该化合物是通过二苯并[a,j]氧杂蒽中的含氧六元杂环和芴中的五元环共用一个碳原子形成一个螺环. 利用荧光光谱和热分析等手段对该化合物的性质进行了研究,结果表明其最大荧光发射峰为366 nm,熔点为297 ℃,热分解温度为329 ℃,具有较高的热稳定性.     

含磷稠环8,9,16,17-四脱氢-6,14-二硫羰基-6,14-二巯基-7,8,15,16-四氮-5,13-二氧-6,14-二磷杂二苯并[a,h]蒽烷吡啶盐及其衍生物的合成和结构

本文报道标题化合物及其十一个衍生物的合成方法,测定了该盐及其若干衍生物的分子和晶体结构,并对衍生物的性质、氢核磁共振谱和质谱进行了讨论.     

生物体内含磷化合物的核磁共振研究进展

含磷化合物在机体的能量代谢,脂肪、糖类的代谢,酸碱平衡控制等各种生命活动中都起着非常重要的作用,与疾病、衰老过程息息相关。对于含磷化合物的研究尤为重要。核磁共振技术可以无损伤地、无侵入地获取生物体的信号,使其在生物体内含磷化合物的研究中迅速发展。本文综述了含磷化合物的研究现状,核磁共振技术的特点,以及液体核磁共振、固体核磁共振和核磁共振成像三种技术在含磷化合物方面的应用,并对核磁共振技术检测生物体内含磷化合物的未来发展方向以及遇到的困难进行了介绍。     

三苯基锡(Ⅳ)哌啶氨荒酸酯的合成及结构研究

利用三苯基氯化锡和哌啶氨荒酸钠反应,合成了三苯基锡(Ⅳ)哌啶氨荒酸酯.通过元素分析、红外光谱和核磁共振氢谱对其结构进行了表征.用X-射线单晶衍射测定了该化合物的晶体结构.结果表明,化合物中锡原子呈五配位畸变三角双锥构型.     

稀土杂-2-苯基-3-正丁基茚环状化合物的合成及其对丁二烯聚合的催化活性

二苯乙炔和正丁基锂在乙醚中反应得到中间体,使之进一步与无水氯化稀土反应得到了化合物（I），将化合物（I）与环戊二烯钠在四氢映喃(THF)中反应得到了化合物(I).通过元素分析、红外光谱、核磁共振谱和热重分析对所合成的化合物进行了鉴定,并对水解产物做了红外光谱、质谱、核磁共振谱分析.研究了铃化合物(I)与AIEt3组成的催化体系引发丁二烯聚合的反应活性,结果表明,该催化体系对丁二烯聚合有较高活性,并且溶剂和铝比对聚合活性有较大影响。     

Automatic compatibility tests of HSQC NMR spectra with proposed structures of chemical compounds

A recently introduced similarity measure is extended here for comparing two-dimensional spectra. Its applicability is demonstrated with heteronuclear single-quantum correlation (HSQC) NMR spectra. For testing the compatibility of a spectrum with the proposed chemical structure, first, the spectrum is predicted on the basis of that structure and then, the proposed comparison algorithm is applied. In this context, the topics of optimization are peak picking, signal intensity measures, and optimizing the parameters of the two-dimensional comparison method. The performance is analyzed with a test set of 289 structures of organic compounds and their HSQC and ¹H NMR spectra. The results obtained with HSQC spectra are better than those achieved using the previously described one-dimensional similarity test with ¹H NMR spectra alone.     

Application of a new method for simultaneous phase and baseline correction of NMR signals (SINC)

Recently, we presented a new approach for simultaneous phase and baseline correction of nuclear magnetic resonance (NMR) signals (SINC) that is based on multiobjective optimization. The algorithm can automatically correct large sets of NMR spectra, which are commonly acquired when reactions and processes are monitored with NMR spectroscopy. The aim of the algorithm is to provide spectra that can be evaluated quantitatively, for example, to calculate the composition of a mixture or the extent of reaction. In this work, the SINC algorithm is tested in three different studies. In an in-house comparison study, spectra of different mixtures were corrected both with the SINC method and manually by different experienced users. The study shows that the results of the different users vary significantly and that their average uncertainty of the composition measurement is larger than the uncertainty obtained when the spectra are corrected with the SINC method. By means of a dilution study, we demonstrate that the SINC method is also applicable for the correction of spectra with low signal-to-noise ratio. Furthermore, a large set of NMR spectra that was acquired to follow a reaction was corrected with the SINC method. Even in this system, where the areas of the peaks and their chemical shifts changed during the course of reaction, the SINC method corrected the spectra robustly. The results show that this method is especially suited to correct large sets of NMR spectra and it is thus an important contribution for the automation of the evaluation of NMR spectra.     

Advances in Molecular Diamagnetism

At the present state of instrumentation and quantum-mechanical approximations, diamagnetic measurements can supply information on chemical structure which complements the result of other approaches, such as infrared and NMR spectroscopy. General applicability and relatively low cost of equipment are among the advantages of this technique. There is growing interest in the relation to chemical shifts in NMR spectra and in the possibility offered by this technique for testing quantum-chemical approximations.     

茶叶化学成分指纹识别中样品制备方法的优化

根据指纹识别实验对样品的要求, 以¹H NMR和主成分分析(PCA)为测试与评估手段, 对茶叶中化学成分提取条件的优化方法进行了研究. 针对生物指纹识别实验中样本体系复杂及化学组分含量多等特点, 利用主成分分析对检测样品质控的多因素进行综合分析, 最终确立了茶叶中化学成分提取制备的实验条件. 利用所建立的样品制备程序对4种茶叶进行预处理和测试, 结果表明, 所建立的方法稳定、可靠, 可以满足茶叶代谢物¹H NMR指纹识别研究的要求. 本文所提出的优化方法简单可靠, 可用于复杂样本体系标准样品预处理方法的建立.     

13C固体核磁共振测定气体水合物结构实验研究

采用高功率1H去偶结合魔角旋转13C固体核磁共振技术,在低温常压条件下对合成的乙烷和丙烷气体水合物进行了测试,获得了两种纯气体水合物的13C核磁共振谱图,初步建立了固体核磁共振波谱法测定天然气水合物的实验方法.实验表明:乙烷水合物的13C核磁共振谱图中仅有一条谱线(δ7.7),结构类型为sI,且乙烷分子仅填充在大笼中(...     

Fast determination of 13C NMR chemical shifts using artificial neural networks

Nine different artificial neural networks were trained with the spherically encoded chemical environments of more than 500000 carbon atoms to predict their 13C NMR chemical shifts. Based on these results the PC-program "C_shift" was developed which allows the calculation of the 13C NMR spectra of any proposed molecular structure consisting of the covalently bonded elements C, H, N, O, P, S and the halogens. Results were obtained with a mean deviation as low as 1.8 ppm; this accuracy is equivalent to a determination on the basis of a large database but, in a time as short as known from increment calculations, was demonstrated exemplary using the natural agent epothilone A. The artificial neural networks allow simultaneously a precise and fast prediction of a large number of 13C NMR spectra, as needed for high throughput NMR and screening of a substance or spectra libraries.     

Computer-aided Interpretation of Proton Nuclear Magnetic Resonance Spectra (Ⅰ)——An Artificial Intelligence System for Interpretation of Proton NMR Spectra of Polymers

An artificial intelligence system for interpretation of proton NMR spectra of polymers is reported in this paper. The system, including spectra data base, knowledge data base and reasoning engine, is based on the characteristics of the proton NMR spectra of polymers and the spectra interpretation experiences of specialist. The system can partly simulate human thinking and interpret proton NMR spectra of polymers at different levels of sophistication. The program in the system was written in Turbo Prolog 2.0 and translated into machine language by computer compiler. It has been tested on an IBM PC/XT computer and a satisfactory result was given.     

不饱和烯酸酰基硫脲化合物的合成与抑菌活性测定

采用山梨酸和肉桂酸为先导化合物,经过酰氯化和硫脲化,引入活性的环状化合物,合成了6个新化合物,经核磁共振氢谱、红外光谱和元素分析测定,确认了新化合物的结构.在此基础上对目标化合物进行了防治辣椒枯萎病菌、小麦赤霉病菌、马铃薯晚疫病菌的生物活性测试.结果表明,部分化合物有一定的抑菌活性.     

TG-DTA study of melamine-urea-formaldehyde resins

The thermal behaviour of MUF resins from different suppliers with different content of melamine was studied, along with the ¹³C NMR spectroscopic analysis of resin structure and the testing of particleboards in current production at Estonian PB factory Pärnu Plaaditehas AS. The chemical structure of resins from DMSO-d₆ solutions was analysed by ¹³C NMR spectroscopy on a Bruker AMX500 NMR spectrometer. The melamine level in different MUF resins is compared by the ratios of carbonyl carbon of urea and triazine carbon of melamine in ¹³C NMR spectra. Curing behaviour of MUF resins was studied by stimultaneous TG-DTA techniques on the Labsys? instrument Setaram. The shape of DTA curves characterisises the resin synthesis procedure by the extent of polymerisation of UF and MF components and is in accordance with structural data.