缩胺基硫脲衍生物电子结构的HeI紫外光电子能谱研究

报道了一组具有生物活性的缩胺基硫脲衍生物电子结构的HeI紫外光电子能谱(PES)研究。PES谱的指认借助于对有类似原子基团的小分子的PES结果以及对每个研究分子的MNDO量子化学计算,同时由PES实验最低电离能(IP_s/eV)预指了该类衍生物间的相对生物活性大小,而研究分子最高占有轨道(HOMO)的π键属性促进了人们对这类衍生物生物活性的了解。     

缩胺基脲及硫脲衍生物的X射线光电子能谱研究

脲素或硫脲与直链或支链烷烃形成包结物的性质可用来分离两者.人们对其衍生物也给予了一定关注.迄今未见对此类衍生物的X射线光电子能谱研究.本文合成了一组缩胺基脲及硫脲衍生物,并研究了它们的X射线光电子内壳层谱、振起伴峰及其价带谱.用振起伴峰表征了它们各自的共轭程度,并探讨了苯环上的取代基效应.     

缩氨基脲类和缩氨基硫脲类衍生物的质谱研究

用高、低分辨质谱,重氢标记和亚稳跃迁研究了代缩氨脲和缩氨基硫脲类衍生物的质谱碎行为。结果表明,分子离子的丰度、基峰离子的生成方式以及碎非离子的种类、丰度和数量主要取于取代基R的诱导效应和共轭效应的综合影响。质谱的碎裂特征是:(1)当R为N(CH2)2,OH分子的电子云分布均匀,共轭性好,基峰为分子离子峰。(2)当R为H,F时缩氨基脲8-N位缺子最甚,导致9-N和10-C之间键的断裂,生成的高稳定离子ρ-RC6H4CH=N[+]=NH为墓峰。缩氨基硫脲类衍生物,因电子云分布均匀,基峰仍为分子离子峰。(3)当R为Br,NO2时,由于诱效应强烈,分子的电子云分布不均匀,12-O(或12-S)成为缺电子最甚的原子,8-N和9-N之间键裂、重排而生成的离子-HNC(NH2)=XH]:(X=O,S)为基峰。(4)H-NH2基团重排到苯环5位上,生成离子(O-RC6H4NH2).+[1]。只有当R为H时,反应最易反生。R为强电子基或强极电基,对反应都不利。     

N-(2-溴乙基)咔唑与N-乙烯基咔唑的气相HeI紫外光电子 能谱与电子结构研究

首次报道了N-(2-溴乙基)咔唑和N-乙烯基咔唑的气相HeI紫外光电子能谱(UPS),借助于Gaussian94采用RHF/6-31G基组优化几何构型,并用RHF/6-31G^*基组计算分子轨道及能级.在对咔唑和N-烷基咔唑系列分子UPS电离能变化规律研究的基础上,对这2个分子的UPS谱带给予指认,并讨论其电子结构.结果表明N-(2-溴乙基)咔唑的UPS谱与N-烷基咔唑的不同之处是在10.295,10.540eV处出现2个Br原子的孤对轨道;N-乙烯基咔唑的UPS谱带与咔唑的相比,电离能变化的特殊性说明乙烯基与咔唑环共平面。     

二氧化氮的电子结构

本文根据实验事实和定性分子轨道理论讨论了二氧化氮分子的电子结构,指出分子中的大π键不是Π_3~3,而是Π_3~4。本文还讨论了NO_2分子二聚生成N_2O_4分子的结构模型。     

邻硝基乙酰苯胺衍生物电子结构的UPS研究

本文报道邻硝基乙酰苯胺衍生物的HeI紫外光电子能谱(PES), 同时也给出了邻硝基苯胺衍生物的PES谱。PES谱的指认由相应分子的MNDO计算所支持, 并指出带有不同取代基基团的邻硝基乙酰苯胺合成耐高温喹啉高聚物的难易依赖于PES所测化合物分子的最低电离能(IP)。     

丙酰基二茂铁取代缩氨基脲的合成

丙酰基二茂铁和4-取代氨基脲反应制得8个相应的缩氨基脲1～8, 它们均属首次制得. 产物经用元素分析, IR, ^1H NMR确认其结构 .     

给、吸电子基团对吡嗪衍生物电子结构影响的DFT研究

采用B3LYP方法在6—31G^#基组水平上优化了对位取代吡嗪衍生物的几何构型，利用TD—DFT方法计算了它们的前线分子轨道能级和电子光谱．结果表明，带有给、吸电子基团对吡嗪衍生物与苯、吡啶相比，也具有很好的共轭性；随着分子共轭链的增长，分子的偶极矩增大，前线分子轨道能级差减小，最大吸收波长发生红移．对于具有相同共轭链的同分异构体，推电子基团与具有给电子性质的共轭链相连，则分子的电荷转移明显，导致偶极矩增大，前线分子轨道能级间的电子跃迁更容易；吸电子基团与具有给电子性质的共轭链相连，情况正好相反，这些结果对分子设计有重要意义。     

聚对苯撑乙烯齐聚物及其衍生物电子结构和发光机理的理论研究

运用量子化学从头算ab initio HF方法对聚对苯撑乙烯剂聚物及其衍生物的几何结构进行了优化,分析了前线分子轨道成分,确认了电子光谱的跃迁轨道。计算结果表明,聚苯撑乙烯剂聚物及衍生物的电子云分布与其结构密切相关,不同取代基修饰下的二聚苯撑乙烯的电子光谱发生红移,且随取代基推电子能力加强红移显。电子光谱跃迁主要是最高占据轨道向最低空轨道之间的π－π^*跃迁,计算结果和实验吻合得很好。     

推、拉电子基团对水杨醛缩胺分子电子结构和非线性光学性质的影响

采用量子化学半经验FF／PM3方法,讨论了水杨醛缩苯胺分子中两苯环的对位被推、拉电子基团取代后,体系电子结构和非线性光学性质的变化,考查了分子电子结构对非线性光学性质影响的微观本质,得到的具有给体－共轭桥键－受体型结构的水杨醛缩苯胺分子应显示良好的非线光学性质。     

Semicarbazones and thiosemicarbazones,XII: Crystal structure of salicylaldehyde semicarbazone

Summary The crystal and molecular structure of salicylaldehyde semicarbazone was obtained by single crystal X-ray diffraction. The O atom of the semicarbazone fragment isanti to the N atom of the hydrazinic group. The distribution of bond lengths in the semicarbazone fragment indicates delocalization of the -electrons. The crystal structure is stabilized by intra- and intermolecular hydrogen bonds.

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Semicarbazone und Thiosemicarbazone, 12. Mitt.: Die Kristallstruktur des Salicylaldehyd-Semicarbazons

Zusammenfassung Die Kristallstruktur und die molekulare Struktur des Salicylaldehyd-Semicarbazons wurde über Einkristall-Röntgenstreuung ermittelt. Das O-Atom des Semicarbazonteils stehtanti zum N-Atom der Hydrazin-Gruppierung. Die Bindungslängen in der Semicarbazoneinheit zeigen eine Delokalisierung der -Elektronen an. Die Geometrie der Verbindung wird durch stabilisierende intra- und intermolekulare Wasserstoffbrückenbindungen bestimmt.

     

基于2,6-二乙酰基吡啶二缩氨基脲和硅钨钒杂多酸构建三阶非线性光学材料

以多酸阴离子簇为主体,选用2,6-二乙酰基吡啶二缩氨基脲(DAPSC)为有机配体,在水热条件下,设计合成了新型的基于单钒取代的Keggin型多酸基无机-有机杂化配合物[Ni(H_2O)_2(DAPSC)][H_3SiW_(11)VO_(40)]·7H_2O.单晶结构分析表明该化合物是零维结构,由平面型席夫碱修饰的多酸基配合物.此外,通过元素分析、红外光谱、粉末X射线衍射、能谱分析等方法对其结构进行表征,并探索研究了其三阶非线性光学性质.     

一元硝酸酯热解反应的理论研究

运用SCF－AM1－MO方法，计算研究了十个一元硝酸酯的热解反应，揭示了烷基取代对反应过程的影响．UHF计算O－NO2键均裂产生RCH2O·和·NO2两个自由基的反应活化能较低，是硝酸酯热解的主要途径;RHF计算α-H转移环消除产生RCHO和HONO的反应具有较高活化能，且α-C上含两个以上取代基时不发生该反应．还探索性地进行了C－O键断裂的UHF和RHF计算．.     

Absorption spectra and structure of benzimidazoquinozalinone derivatives

Infrared and electronic spectroscopy and X-ray fluorescent analysis were used to study the structures of 5,6-dihydrobenzo[4,5]imidazo[1,2-c]quinazolin-6-one and its 5-ethyl and carboxy and sulfo derivatives. The latter compounds we obtained for the first time. The ketone and its monocarboxy derivative exist as lactam tautomers, and the sulfo derivative, in the zwitter ion form. Electronic and energy characteristics of the compounds were calculated by the Pariser-Parr-Pople method.     

Unreported coordination behaviour of a bis(semicarbazone) ligand in a lead(II) complex

A novel lead(II) complex with the Schiff base benzil bis(semicarbazone), [Pb(LH₂)₂(NO₃)]NO₃ · 1/2H₂O, has been synthesised and structurally characterized as well as the free ligand. The coordination number of Pb(II) is seven provided by two neutral ligand molecules and one nitrato group. The most interesting characteristic of this complex is the different behaviour observed in the two bis(semicarbazone) molecules. One of them is a N₂O₂ chelate ligand, whereas the other one is bonded to the lead ion only through one of the semicarbazone branches. The seventh position in the lead coordination sphere is provided by one oxygen atom from a nitrato ligand.     

Vibrational spectra and structure of 1,2,4-triazole derivatives

The frequencies and forms of the normal vibrations of the anions of 1,2,4-triazole and 3-nitro-, 3-nitro-5-methyl-, and 3,5-dinitro-1,2,4-triazoles were calculated. The potential energy constants were calculated by solution of the reciprocal spectral problem, and the frequencies in the experimental spectra were assigned to the fundamental types of normal vibrations. It is shown that the nitro groups in the 3 and 5 positions in the anions of the triazoles are located in the plane of the triazole ring. The coordination of the metal in crystalline salts of nitrotriazoles was studied by the methods of vibrational spectroscopy, and an assumption is stated that the most probable position of the metal is near the oxygen atoms of the nitro group along the Me-O-N line. As a result of a theoretical analysis of the vibrational spectra of the anions it was ascertained that equalization of the lengths of the ring CN bonds does not occur during ionization of the covalent triazoles. Calculations by the MO LCAO SCF method are in agreement with the data from vibrational spectroscopy.See [1] for communication III.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1423–1431, October, 1973.     

A theoretical study on the ionization of furan with analysis of vibrational structure of the photoelectron spectra

Summary Ab initio calculations have been performed to study on the molecular structures and the vibrational levels of the low-lying ionic states (²A₂ and²B₁) of furan. The equilibrium molecular structures and vibrational modes of these states are presented. The theoretical ionization intensity curves including the vibrational structures of the low-lying two ionic states are also presented and compared with the photoelectron spectrum. A number of new assignments of the photoelectron spectra are proposed.     

Vibrational spectra and structure of 1,2,4-triazole derivatives

From an analysis of the IR and Raman spectra and a calculation of the frequencies and forms of the normal vibrations of the nitrotriazoles, conclusions have been drawn on the structure of 3,5-dinitro-1,2,4-triazole and 1-methyl-3,5-dinitro-1,2,4-triazole. The nitro group in position 3 of the triazole ring is located in the plane of the molecule, and that in position 5 is rotated about the CN bond. The spatial nonequivalence of the nitro groups leads to the splitting of the absorption bands in the IR spectra that are characteristic for the anti- and synphase vibrations of the nitro groups.For Communication (II), see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1194–1198, September, 1973.