甲酰基及乙酰基吡咯烷、哌啶、吗啡啉的13C NMR谱图研究

测定了一系列N-甲酰基、N-乙酰基环胺的¹³C NMR谱,对甲酰基、乙酰基对于环胺上的C原子的影响进行了讨论,影响因素主要在于C-N键的部分双键性,以及基团的空间效应.     

N-(2-苯基-1,2,3-连三唑-4-甲酰基)-N′-芳基硫脲的13C NMR谱的研究

研究了最近合成的6种N-(2-苯基-1,2,3-连三唑-4-甲酰基)-N′-芳基硫脲新化合物. 通过测定6种新化合物的13C NMR和DEPT谱等,对其结构进行了确定,并对其全部谱峰做出归属; 并给出了这类新化合物中苯的两个新取代基(-R1 和-R2 )的取代参数; 同时,讨论了化学位移与分子结构间的一些关系.     

N-(2-苯基-1,2,3-连三唑-4-甲酰基)-N′-芳基硫脲的13C NMR谱的研究

研究了最近合成的6种N-(2-苯基-1,2,3-连三唑-4-甲酰基)-N′-芳基硫脲新化合物. 通过测定6种新化合物的¹³C NMR和DEPT谱等,对其结构进行了确定,并对其 全部谱峰做出归属;并给出了这类新化合物中苯的两个新取代基(R₁ 和R₂ )的取代参数;同时,讨论了化学位移与分子结构间的一些关系.     

一个含苯并咪唑环的酰氨基硫脲NMR研究

该文合成了一个新的在医药方面具有潜在应用价值的含苯并咪唑环的酰氨基硫脲化合物,即4-(4-甲氧基苯基)-1-[2-(4-硝基苯氧基甲基)-苯并咪唑-1-基\]甲酰基氨基硫脲,并利用元素分析、IR和NMR对其结构进行了表征. 通过NOESY谱确定了其两种异构体(A和B)的构型,并利用2D NMR技术对它们的¹H NMR 和¹³C NMR谱进行了全归属,给出了相应的偶合常数和两种异构体的含量.     

双-(二烷基膦)乙烷合铂配合物的~(13)C NMR研究

本文报道Cis-Pt(disphos)X_2系列化合物的~(13)C NMR研究。发现配体X、取代基R对桥环碳(C_1)化学位移有明显的影响;并证实了某些化合物象异构体的存在,还对构象特性进行了讨论。     

对氯苯甲酰芳肼化合物的合成及其氧化脱氢研究

以取代苯肼、自制的对氯苯甲酰氯为原料,用冰浴法合成了2种对氯苯甲酰芳肼化合物;并用N-溴代丁二酰亚胺(NBS)/吡啶氧化体系脱氢得2种对氯苯甲酰芳基偶氮化合物,产品的结构经元素分析、IR、1HNMR确证,产率在80%—89%之间;所合成的化合物尚未见文献报道。     

双-(二烷基膦)乙烷合铂配合物的13C NMR研究

本文报道Cis-Pt(disphos)X₂系列化合物的¹³C NMR研究。发现配体X、取代基R对桥环碳(C₁)化学位移有明显的影响;并证实了某些化合物象异构体的存在,还对构象特性进行了讨论。     

四种4-N,N-二苯胺基均二苯乙烯类电致发光材料电子结构和光谱性质的理论计算

用从头算HF和密度泛函B3LYP方法对4种4-N,N-二苯胺基均二苯乙烯类化合物4-N,N-二苯胺基均二苯乙烯(a)、2-氯-4'-N,N-二苯胺基均二苯乙烯(b)、2,6-二氯-4'-N,N-二苯胺基均二苯乙烯(c)及2,6-二甲氧基-4'-N,N-二苯胺基均二苯乙烯(d)进行全优化,并用CIS优化a及d分子的激发态结构.用TDDFT方法计算吸收和发射光谱,考查了溶剂对吸收光谱的影响.结果表明,该类化合物在基态与激发态的跃迁,主要是电子云分布从离域到定域的转变.吸收及发射光谱的计算结果与实验值一致,溶剂对四种化合物的吸收光谱影响不大,而对化合物b及c的强度影响较大.     

苄基保护甘露糖羧酸酯的NMR研究

应用NMR技术研究了1-0-(3,5-二硝基苯甲酰基)-2、3、4、6-四-0-苄基-D-吡喃甘露糖的α、β异构体的构型和糖环上碳氢归属情况,总结了苄基保护甘露糖羧酸酯构型的确证方法及影响糖环上碳氢化学位移的一些规律;并对其它13种四苄基甘露糖羧酸酯的NMR谱进行了研究,提供了这些化合物的¹³C和¹H NMR数据.     

C60-脱异丙基脱氢枞胺衍生物的NMR光谱分析

C_(60)与脱氢枞胺发生环加成反应可生成多种功能性富勒烯衍生物.该论文测定了目标化合物N,N-四氯邻苯二甲酰基-13-硝基-7,7-C_(60)-脱异丙基脱氢枞胺的~1H NMR和~(13)C NMR谱图,并利用~1H-~1H COSY、~1H-~1H ROESY、~1H-~(13)C HSQC和~1H-~(13)C HMBC等2D NMR技术,对其~1H和~(13)C NMR信号进行了归属,为表征类似化合物的结构提供了参考.     

Experimental (FT‐IR) and theoretical (DFT) studies on prototropy and H‐bond formation for pyrazine‐2‐amidoxime

The results of the first structural studies (with the use of both experimental and theoretical methods) on pyrazine‐2‐amidoxime (PAOX) were shown and discussed. FT‐IR spectra were recorded in different concentrations of the PAOX in apolar solvent to check the possibility of the inter‐ or intramolecular hydrogen‐bond formation. All possible tautomers–rotamers of PAOX were then theoretically considered at the DFT(B3LYP)/6‐311+G** level in vacuo. For selected isomers, calculations were also performed at higher levels of theory {B3LYP/6‐311+G(3df,2p) and G3B3}. Based on the results of DFT calculations, the most stable isomers were found, and their total free energies and infrared spectra were calculated. The energy variation plots for the N8?C7?N9?O10 and N1?C2?C7?N9 dihedral angles were also computed to find two energy barriers, one for E/Z isomerization around the C7?N9 double bond and the other one for rotation of the pyrazinyl ring around the C2?C7 single bond. The results show that the stability of the PAOX isomers strongly depend on their configuration and orientation of the substituents. The possibilities of inter‐ and intramolecular hydrogen bonds were also experimentally and theoretically checked. Finally, a potential of mean force was determined in CHCl₃ for a dimer of PAOX with hexamethylphosphoramide. Both, experimental and theoretical results are in agreement. Copyright © 2016 John Wiley & Sons, Ltd.     

四种芳香稠环化合物荧光光谱的量子化学研究

芳香稠环化合物是一类重要的化合物,并且一般具有较大的共轭体系,是一类良好的电致发光材料.这类物质的光谱在近来的科学研究中已经成为了一个热点.对4种芳香稠环化合物的荧光光谱进行了理论研究.采用量子化学半经验方法RHF/PM3对4种化合物的构型进行了全参数的优化.并对优化后的构型作了振动分析,均未出现虚频率,说明所得优化构型基本合理.在此基础上,采用单激发组态相互作用方法(CIS)计算4种化合物的荧光光谱,所有计算结果与实验值基本吻合.     

Spectral Studies On Some 2-Quinolones

Spectral properties of some 2-Quinolones were investigate-ed. IR and ¹H NMR were applied to characterize the ligands. The hydrogen bond property is of important parameter for controlling the behaviour of the compounds. The N[sbnd]H, O[sbnd]H, C[dbnd]O, C[sbnd]H, and C[sbnd]N fundamental functional groups are characterized. The electronic transitions are assigned. The data are explained on the basis of molecular structure and substituents effects. The acid-base equilibria and the phenomena of tautomerism for these compounds are explained and discussed. The acid exponents (pK_OH, and pK_NH) are evaluated.     

3种黄酮醇类化合物核磁共振碳谱的理论研究

在B3LYP/6-31G水平下优化了3种黄酮醇类（山奈酚,槲皮素,杨梅素）化合物的几何构型. 在振动分析中,均未出现虚频率. 在B3LYP/6-31G的水平下计算了该类化合物的核磁共振碳谱. 研究结果表明：3种分子均有分子内氢键形成,且分子内氢键的键长为0.17~0.18 nm左右 . 本文讨论了羟基引入之后对邻近C的化学位移的影响. 从取代基对NMR的影响来看,随着取代基对苯环的供电子能力的加强,取代基邻近的一些C的化学位移有所改变.      

C72O3的结构和光谱的理论研究

采用AM 1方法理论研究了C70 五元环酸酐衍生物C72 O3 的 8种可能异构体的结构和稳定性 ;以各异构体稳定构型为基础 ,分别用AM 1和ZINDO/CI方法计算了它们的振动光谱和电子光谱。结果表明 ,酸酐基团—C2 O3 主要加成在CⅠ CⅡ(异构体A)和CⅢ CⅢ(异构体B)键上形成闭环结构 ,异构体B的稳定性与实验已证实存在的异构体A十分相近 ;异构体A的振动光谱理论计算值与实验值符合较好 ,B的振动光谱理论计算值与A相似 ;对C72 O3 各异构体的电子跃迁进行了理论指认 ,讨论了其电子光谱的红移现象 ;其他异构体的振动和电子光谱属于理论预测。     

Properties of isolated DNA bases, base pairs and nucleosides examined by laser spectroscopy

The vibronic spectra of laser desorbed and jet cooled guanine (G) adenine (A), and cytosine (C) consist of bands from four, two and two major tautomers respectively, as revealed by UV-UV and IR-UV double resonance spectroscopy. The vibronic spectrum of adenine around 277 nm consists of weak nπ^* and strong ππ^* transitions, based on IR-UV and deuteration experiments. Precise ionization potentials of G and A were determined with 2-color, 2-photon ionization. We also measured vibronic and IR spectra of several base pairs. GC exhibits a HNH ^... OH/NH ^... N/C=O ^... HNH bonding similar to the Watson-Crick GC base pair but with C as enol tautomer. One GG isomer exhibits non-symmetric hydrogen bonding with HNH ^... N/NH ^... N/C=O ^... HNH interactions. A second observed GG isomer has a symmetrical hydrogen bond arrangement with C=O ^... NH/NH ^... O=C bonding. Two CC isomers were observed with symmetrical C=O ^... NH/NH ^... O=C bonding and nonsymmetrical C=O ^... HNH/NH ^... N interaction, respectively. Guanosine (Gs), 2-DeoxyGs und 3-DeoxyGs each exhibit only one isomer in the investigated wavelength range around 290 nm with a strong intramolecular sugar(5-OH) ^... enolguanine(3-N) hydrogen bond. Received 16 June 2002 / Received in final form 15 July 2002 Published online 13 September 2002     

C_8H_8O_7H_2O单晶的振动光谱

Ｃ８Ｈ８Ｏ７Ｈ２Ｏ单晶的振动光谱李丽霞（山东大学环境工程系济南２５０１００）ＴｈｅＶｉｂｒａｔｉｏｎａｌＳｐｅｃｔｒｕｍｏｆＣ８Ｈ８Ｏ７Ｈ２ＯＣｒｙｓｔａｌＬｉＬｉＸｉａ（ＥｎｖｉｒｏｎｍｅｎｔａｌＥｎｇｉｎｅｒｉｎｇＤｅｐａｒｔｍｅｎｔ，Ｓｈａｎｄ...     

Spectroscopic Studies of Intra- and Inter-Molecular Hydrogen Bonding of Some O-Hydroxylbenzenesulfonanilides in Solutions

The effect of solvent on the electronic spectra of some fasciolici-dal o–-hydroxylbenzenesulfonanilides is examined and discussed. It is revealed that in solution these compounds exist in both intramolecular hydrogen bond form and intermolecular hydrogen bond form occurring between solute and solvent molecule. In solutions containing large amount of apolar aprotic solvents such as dioxane, compounds studied are mainly intramolecular hydrogen bond form and exhibit a weak transition band which is presumably attributed to the transition of n-electrons of oxygen atom in the intramolecular hydrogen bonded six-membered ring of the compounds.     

分子内氢键对芳氢化学位移值影响的研究

通过对19个酚类化合物¹H NMR谱的研究和分析发现,酚羟基形成分子内氢键后,使对位芳氢化学位移值向高场变化的幅度大于邻位,其差值约为0.1ppm-0.3ppm.