氮杂冠醚的研究Ⅱ.N-取代苯并氮杂冠醚的1H和13CNMR谱

本文研究了15种新合成的单、双N取代二苯并18冠6的¹H及¹³C NMR谱。结果表明,¹³C NMR谱的化学位移能显示分子的电荷分布,而¹H NMR谱的偶合常数则部份地反映了大环的构象。氮原子的杂入大环结构和取代基的改变对聚醚环上的电荷分布影响的结果说明,这些改变可能会对冠醚的络合作用发生影响。     

苯并氮杂冠醚结构与溶剂效应及某些其它性质的核磁共振研究

本文记取并归属了二十一种以前未见文献报道的N-取代苯并氮杂冠醚化合物在氯仿中的¹H和¹³C NMR谱,提供了一批原始数据。讨论了这批化合物中氮原子上取代基对于其¹H和¹³C NMR行为的影响以及(胺类)苯并氮杂冠醚化合物在溶液中的构象转动问题。按其不同的NMR待性将这批新合成的化合物分成酰胺类苯并氮杂冠醚化合物(Ⅰ系列)和胺类苯并氮杂冠醚化合物(Ⅱ系列)两个系列(见图);并确认Ⅱ系列化合物在氯仿中都有所谓"稀释位移效应",而Ⅰ系列化合物在同样的条件下不发生稀释位移效应。     

冠醚过渡金属络合物的振动光谱

以三种冠醚为配体制备了一系列过渡金属(Cr、Fe、Mn、Co、Ni、Cu)的硝酸盐、氯化物的络合物并考察了它们的红外及拉曼光谱。结果表明,络合物形成后,v_(c-o-c)、σ_(CH2)、-环弯曲和“环呼吸”振动的变化很有规律,并可作为络合物形成的判据。18-冠-6的络合物具有与含水稀土冠醚络合物相似的结构;12-冠-4、15-冠-5的络合物则有与碱金属冠醚络合物相近的结构。而且三种氯化钴的络合物中存在[Co~(2+)-冠醚]CoCl_4~(2-)的结构。     

冠醚过渡金属络合物的振动光谱

碱金属、碱土金属、稀土元素的阳离子冠醚络合物和它们的振动光谱研究已有文献报导。但关于过渡金属阳离子冠醚络合物的文章却不多。我们的目的是制备一系列典型的冠醚过渡金属络合物,并测定它们的红外,拉曼光谱,寻找络合物形成前后的光谱变化规律,希望通过光谱研究得到一些结构信息。     

苯并十五冠五冠醚的电子光谱研究

研究了九种不同取代基的新型苯并十五冠五冠醚化合物的电子光谱,首次测定了这些化合物的紫外吸收带与摩尔消光系数,并讨论了它们与结构间的关系。     

取代酰基二苯并二十四冠八冠醚的红外光谱特征

首次测试了八种不同取代酰基二苯并二十四冠八冠醚的红外光谱,归属了其特征吸收频率并讨论了它们与结构的关系。     

九个苯并冠醚的13C-NMR谱研究

本文测定了九个苯并冠醚的¹³C-NMR和¹H-NMR谱,结合元素分析、红外、紫外、质谱等数据,确定了这些冠酸的分子结构。根据NMR谱的谱线位置、裂分情况及取代基诱导效应,归属了全部¹³C-NMR谱线。并讨论了苯环上不同取代基对冠醚环上各碳化学位移的影响。     

N-取代苯并氮杂冠醚及双冠醚的1H和13C NMR谱

本文对新合成的十一个N-取代苯并氮杂冠醚和三个苯并氮杂双冠醚的¹H和¹³C NMR谱;作了记录和归属;提供了一批原始数据;对一些结构影响因素进行了讨论。     

Vibrational Spectra of Layer Crystals

Abstract

Layer crystals have received considerable attention of spectroscopists because of the wide range of electrical and optical properties they possess. The group of layered chalcogenide crystals contains insulators, semiconductors, metals, and superconductors at moderately high temperature. The layered halide crystals act as reliable hosts for Jahn-Teller, ESR, and other optical experiments. The layerlike nature of such crystals leads to experimentally distinguishable lattice optical properties. The existence of layer and crystal symmetries is clearly manifested in the vibrational spectra of these crystals which have been determined in recent years by means of infrared and Raman investigations of the zone center modes. The large anisotropy of electrical properties leads to LO-TO splitting, while the small interlayer interaction gives rise to Davydov-type splitting besides low frequency interlayer modes. Thus investigations of such crystals have been a considerable addition to our knowledge of the vibration spectra of crystals, in general. In fact, a few of these studies provide very transparent examples of the subject.     

瘦长红珊瑚的振动光谱研究

瘦长红珊瑚是台湾贵珊瑚中最主要的品种,其颜色分布独具特色。以瘦长红珊瑚为研究对象,采用电子探针、X射线粉晶衍射、红外光谱和拉曼光谱对其进行测试分析。结果显示样品的矿物成分为高镁方解石,次要成分的含量稳定,样品中的生物成因方解石存在晶格畸变。实验探测到的代表有机质成分的1 517/1 128cm-1和1 296/1 016cm-1成套谱峰表明样品的红色与该有机成分有关。     

乙基苯的振动光谱和量化计算

用单色双光子共振电离方法研究了乙基苯的第一激发态的振动光谱. 从基态跃迁到第一激发态的带源位置出现在37586 cm^-1处.获得的第一激发态振动光谱超过了2000 cm^-1,并观察到了几个乙基取代基的扭转振动和与苯相似的正则振动. 同时,用含时密度泛函理论和单组态相互作用(CIS)方法计算了第一激发态的跃迁能量,用Hartree-Fock和CIS方法优化了基态和第一激发态分子结构,预测了振动频率. 基态和激发态结构的优化结果均显示为顺式结构,即乙基取代基的对称面垂直了苯基平面.     

Vibrational Spectra and Assignments for 3,4-Dibromothiophene

Abstract

The infrared spectrum of 3,4-dibromothiophene has been studied from 4000 to 200 cm^?1. The Laser Raman spectrum has also been recorded and depolarization values have been measured. An assignment of the 21 fundamental vibrations is proposed based on group frequency correlations, Raman polarization data and comparison with the spectra of parent and some halogeno-substituted molecules.     

白钨矿的振动光谱与颜色成因初探

四川虎牙雪宝顶钨锡铍矿产出晶体硕大、形态完好的橘红色等颜色鲜艳的白钨矿。文章针对白钨矿颜色成因,利用X光粉晶衍射仪、电子探针、红外光谱仪和拉曼光谱仪对4组白钨矿样品谱学特征和化学成份进行研究。X光粉晶衍射仪获得了白钨矿的晶胞参数;电子探针分析获得该地颜色鲜艳的和无色白钨矿及其他无色白钨矿的化学成分;采用红外光谱和拉曼光谱分析了白钨矿的谱学特征并对特征吸收谱带和特征峰进行了归属。电子探针测试结果表明该区白钨矿化学成分接近理想值,振动光谱特征与一般白钨矿相类似表明不同颜色的白钨矿晶体结构基本一致。由此根据晶体场理论在颜色成因方面的解释推测橘红色白钨矿的颜色成因可能与白钨矿中超微晶体结构、矿物中微量元素或稀土元素有关。     

Vibrational and SERS Spectra of Spermine Phosphate Hexahydrate

FTIR, Raman and SERS spectra of spermine phosphate hexahydrate have been recorded and analysed. Vibrational spectra show the protonation of amino and imino groups indicated by the presence of HPO₄ ^2- ion. The molecule is found to be adsorbed to the metal surface through nitrogen and oxygen atoms of the molecules. Distortion of the HPO₄ ^2- ion, change of symmetry of the molecule due to chemisorption and the enhancement in intensity of the amino group vibrations are discussed.     

质子化丙酮分子团簇的结构和振动光谱

用密度泛函B3LYP/ 6 3 1G(d)方法 ,对质子化丙酮分子团簇 (CH3COCH3) nH+ (n =1～ 7)弱相互作用体系进行了全自由度能量梯度优化 ,得到了该系列团簇的稳定结构及其对应的体系能量 .通过对构型的分析得出了质子化丙酮分子团簇 (CH3COCH3) nH+ (n =1～ 7)的生长规律 .计算了中性丙酮分子团簇体系的质子亲合能并总结出其变化趋势 .分析讨论了质子化团簇的红外振动光谱 ,发现质子化团簇的振动光谱普遍较中性环型团簇的振动光谱复杂 ,最强的振动峰来源于质子在溶剂壳中两个氧原子之间的振动 ,而且随着团簇尺寸的增加羰基的伸缩振动峰的数目也随之增多     

Infrared Spectra and Vibrational Analysis of m-Halogen Benzophenones

As a part of a continuing research program on the relationship between vibrational properties and molecular structure of -phenones (aceto- (1,2), and benzo- (3)) developed in this Laboratory, the results of i.r. measurements and assignments for a number of m-halogen benzophenones are presented here. The presence of rotational isomers has been deduced in the molecules examined and the observed features arising from their existence have been elucidated in the interpretation of the infrared spectra.     

Neutron Scattering and Vibrational Spectra of Molecular Crystals

Infrared and Raman spectra of a number of molecular crystals have been measured for studying molecular vibrations and the intermolecular and intramolecular force fields. The infrared absorption bands arise from interaction of the electric wave with the oscillating dipole moment of the crystal. Raman scattering covers inelastic photon scattering processes and accordingly Raman lines arise from the oscillating polarizability of the crystal. Thus, the vibrational modes observed in infrared absorption or Raman scattering spectra are k = 0 modes, for which translationally equivalent molecules vibrate in phase.