阴离子对水的羟基伸缩振动拉曼光谱的影响

通过比较纯水、NaX(X=F, Cl, Br, I)、Na2S、NaOH、NaNO3、Na2CO3、Na2SO4溶液的羟基伸缩振动拉曼光谱, 发现所研究的阴离子对水的结构都有破坏作用. 通过比较阴离子对水的羟基伸缩振动拉曼光谱的影响, 可将所研究的阴离子分为两类, 一类阴离子有F−、OH−、S2−、CO32−, 另一类阴离子有Cl−、Br−、I−、NO3−和SO42−. 它们的主要区别在于对羟基伸缩振动拉曼光谱3600 cm−1、2900−3100 cm−1处影响不同, 产生这些区别的原因在于阴离子与水分子之间氢键的强弱. 阴离子对水的羟基伸缩振动拉曼光谱的影响因素有离子半径、离子电荷和离子结构, 它们的影响程度为离子结构>离子电荷>离子半径.     

A theoretical study of electronic excited states of photosynthetic reaction center in Rhodopseudomonas viridis

The electronic singlet vertical excited states of photosynthetic reaction center (PSRC) in Rhodopseudomonas (Rps.) viridis were investigated by ZINDO and INDO/S methods. The effects of the interactions of pigment-pigment and pigment-protein on the electronic excitations were examined. The calculation results showed that the interactions of pigment-pigment and pigment-protein play an important role in reasonably assigning the experimental absorption and circular dichroism (CD) spectra of PSRC in Rps. virids. By comparing the theoretically computed excited states with the experimental absorption and CD spectra, satisfactory assignments of the experimental spectroscopic peaks were achieved.     

取代基对卟吩结构和性质的影响

运用密度泛函理论(DFT) B3LYP/6-31G(d, p)方法, 对卟吩及其被取代基—CH=CH₂、—COCH₃、—CHOHCH₃、—CHNH₂CH₃或—CHSHCH₃所修饰后的分子构型进行了优化. 同时, 对其电子吸收光谱与核磁共振氢谱也进行了量化计算. 结果表明, 这些取代基有着各自不同的空间构象, 对卟吩环的整体结构没有很大的扰动. 然而, 它们重新调整了卟吩环中原子电荷的分布, 改变了前线分子轨道(LUMO-HOMO)能隙, 结果导致卟吩的吸收光谱与¹H NMR均发生了相应的改变.     

不同交联度的杜仲胶的红外光谱研究

研究了不同交联度的杜仲胶在室温及加热后红外光谱的变化规律．发现在室温下测定的样品红外光谱在低波数内对应链段变形振动的几个特征峰、加热后会消失或弥散，而交联度的改变对其影响不大，即使材料中结晶完全消失而变成高弹态．因此，推测这些特微峰的存在，应该和杜仲胶弹性网络中交联点间链段存在着明显的构象规整性有关．     

Resistance distance and Laplacian spectrum

The resistance distance r _ij between two vertices v _i and v _j of a (connected, molecular) graph G is equal to the resistance between the respective two points of an electrical network, constructed so as to correspond to G, such that the resistance of any two adjacent points is unity. We show how the matrix elements r _ij can be expressed in terms of the Laplacian eigenvalues and eigenvectors of G. In addition, we determine certain properties of the resistance matrix R=||r _ij ||. AcknowledgementsThis research was supported by the Natural Science Foundation of China and Fujian Province, and by the Ministry of Sciences, Technologies and Development of Serbia, within Project no. 1389. The authors thank Douglas J. Klein (Galveston) for useful comments.     

阳极氧化膜WO3（Ⅱ）：电显色的介质效应

用循环计时电量法、循环伏安法、电化学现场(in-situ)紫外可见反射光谱技术和光电流谱技术研究了溶剂和阳离子(H~+,Li~+)对阳极氧化膜WO_3电显色稳定性和过程的影响。从循环计时电量图可以测定表征膜稳定性的氢或锂的累积量和暂态周期数。实验发现W/WO_3/LiCLO_4乙腈溶液体系具有高的电显色稳定性。引起WO_3膜可逆电显色的H~+和Li~+离子的嵌-脱过程的界面电化学机理不同。着色态WO_3膜的色心是自由电子,其密度超过10~(21)/cm~3,生色机理是等离子体振荡。     

Eu（TTA）3·1／2（4，4′－bipyN_2O_2）配合物的发光光谱

在７７Ｋ下测定了Ｅｕ（ＴＴＡ）３·１／２（４，４′－ｂｉｐｙＮ２Ｏ２）配合物的激发光谱、发光光谱和时间分辨光谱。光谱数据表明，在标题配合物中存在化学环境不同的两种Ｅｕ３＋格位，但它们的局部对称性都属于Ｃ２Ｖ点群，这可能表明该配合物的激发态电子结构稍有不同     

On subspectral problem—benzenoid hydrocarbons with common eigenvalues ±1

Summary The method for the contraction and expansion of graphs is used to treat the subspectrality of benzenoid hydrocarbons in relation to eigenvalues ±1. Counts of benzenoid hydrocarbons together with degeneracies of eigenvalues have been carried out for all species having h 7 hexagons. In addition, twelve homologous series are evaluated, and the closed results for the distribution of eigenvalues ± 1 and degeneracies in terms of the number of repeated units are tabulated. This method is universal and applicable to cases sharing other eigenvalues and to nonbenzenoid systems.Also known as Yuan-sun Kiang     

How can the Cross-Link Adducts Formed by Novel Trans Platinum Drug be Influenced by Hydrogen Bond

A systematic quantum chemical characterization of intrinsic structure, energies and spectral properties of all the studied cross-link adducts formed by the novel trans platinum with thiazole ligand has been carried out at B3LYP/6-31G^＊ level of theory with the Lanl2dz pseudo potential basis set for the Pt atom. Special attention has been paid to the relative stability of these complexes and the factors that probably alter the order of the relative stability. The important influence of hydrogen bond on the structures, the energies and the spectral property was revealed. Other factors that contribute to relative stability including solvation effect, entropy and electronic delocalization energy were taken into account. The stability energy of the whole complex, and the interaction energy between two purine bases and the [Pt-（NH3）thiazole]^2＋ group were adopted to study the interplay among subsystems and their contribution to relative stability of all the studied cross-link model. Finally, basic spectral properties of these complexes including H（8） chemical shifts of all the studied complexes and the VCD （vibrational circular dichroism） spectra of two pairs of GG chelate enantiomers, were provided in order to define the structure of the most possible duplex bearing novel trans platinum drug lesions.     

铕（Ⅲ）—β—二酮—4,5—二氮芴—9—酮三元配合物的合成

铕（Ⅲ）┐β┐二酮┐４，５┐二氮芴┐９┐酮三元配合物的合成成义祥徐端钧＊徐元植（浙江大学化学系杭州３１００２７）关键词铕，β－二酮，二氮芴酮，三元配合物，合成，荧光光谱１９９７－０３－３１收稿，１９９７－０７－１５修回噻吩甲酰三氟丙酮（ＴＴＡ）和苯甲...