First Principle Study on the Rectification of Molecular Junctions Based on the Thiol-ended Oligosilane

The electron transport properties of various molecular junctions based on the thiol-ended oligosilane are investigated through density functional theory combined with non-equilibrium Green's function formalism. Our calculations show that oligosilanes doped by the phenyl and-C10H6 groups demonstrate better rectifying effect and their rectification ratios are up to 15.41 and 65.13 for their molecular junctions. The current-voltage(I-V) curves of all the Au/ modified oligosilane/Au systems in this work are illustrated by frontier molecular orbitals, transmission spectra and density of states under zero bias. And their rectifying behaviors are analyzed through transmission spectra.     

The First Principle Study on C-doped Armchair Boron Nitride Nanoribbon Rectifier

The electronic transport properties of armchair-edged boron nitride nanoribbons(ABNNRs) devices were investigated by the first principle calculations. The calculated results show that the ABNNR device doped with carbon atoms in one of the electrodes acts as a high performance nanoribbon rectifier. It is interesting to find that there exists a particular bias-polarity-dependent matching band between two electrodes,leading to a similar current-voltage(I-V) behavior as conventional P-N diodes. The I-V behavior presents a linear positive-bias I-V characteristic,an absolutely negligible leakage current,and a stable rectifying property under a large bias region. The results suggest that C doping might be an effective way to raise ABNNRs devices' rectifying performance.     

基于色胺酮衍生物的阴离子探针和分子逻辑门

通过色胺酮与苯肼反应生成一种新型的腙类化合物.在该化合物的DMF溶液中,用含有不同阴离子的四丁基铵盐测试了其对阴离子的识别能力.实验结果表明,加入F-,AcO-和H2PO-4后,溶液由黄色立即变为橙色,而加入Cl-,Br-,I-,ClO-4,NO-3和HSO-4离子则无变化.通过核磁共振波谱证实了探针的识别机制,并设计了一个四输入的分子逻辑门.     

Molecular Structure of a Chromatographic Chiral Selector Based on a Terguride Derivative

The structure of (+)1-(3-allylpropyl)-(5R,8S,10R)-N,N-diethyl-N-[6-methylergolin-8-yl]urea, C₂₂H₃₃N₄O (allyl-terguride), has been determined as part of a study on the chiral recognition mechanism of ergot alkaloids when they are used as the chiral stationary phase for the separation of racemic mixtures in liquid chromatographic methods. At the pH of the solution used for the crystallization, the molecules of allyl-terguride are protonated at N(6). All bond distances and angles are in the expected ranges. In the asymmetric unit one hydroxide ion is present. Hydrogen bonds join molecules of allyl-terguride in pairs along the b axis, connecting O(2) of the hydroxide ion to O(1) of one molecule and to N(2) and N(6) of another.     

Studies on the Structures and Spectra of Benzothiophene Oligomers

Theoretical studies on a series of oligobenzothiophenes were carded out with the AM 1 and DFT methods. Based on B3LYP/6-31G（D） optimized geometries, the electronic spectra, IR spectra and NMR spectra of the oligomers were calculated by INDO/CIS, AM1 and B3LYP/6-31G（D） methods, respectively. The energy gaps decrease, and the absorption in elec- tronic spectra exhibits a red-shift as polymerization increases. The IR frequencies are little affected by the polymerization and substituents. The ^13C chemical shifts are changed to be upfield since the electron-donating groups increase the electron density of carbon atoms but remain unchanged with the increase of polymerization.     

An Accurate Molecular Structure of Phenyl,the Simplest Aryl Radical

The phenyl radical (C₆H₅^.) is the prototypical σ‐type aryl radical and one of the most common aromatic building blocks for larger ring molecules. Using a combination of rotational spectroscopy of singly substituted isotopic species and vibrational corrections calculated theoretically, an extremely accurate molecular structure has been determined. Relative to benzene, the phenyl radical has a substantially larger C‐C_ipso‐C bond angle [125.8(3)° vs. 120°], and a shorter distance [2.713(3) Å vs. 2.783(2) Å] between the ipso and para carbon atoms.     

An Accurate Molecular Structure of Phenyl,the Simplest Aryl Radical

The phenyl radical (C₆H₅^.) is the prototypical σ‐type aryl radical and one of the most common aromatic building blocks for larger ring molecules. Using a combination of rotational spectroscopy of singly substituted isotopic species and vibrational corrections calculated theoretically, an extremely accurate molecular structure has been determined. Relative to benzene, the phenyl radical has a substantially larger C‐C_ipso‐C bond angle [125.8(3)° vs. 120°], and a shorter distance [2.713(3) Å vs. 2.783(2) Å] between the ipso and para carbon atoms.     

苯甲酮不对称还原反应的理论研究

本文用AM1分子轨道方法研究了1,3,2-噁唑硼烷对苯甲酮的不对称催化还原.反应经历了噁唑硼烷-硼烷配合物的形成及其与苯甲酮的结合、氢转移及脱去噁唑硼烷形成手性产物二级醇-硼烷配合物四步过程.获得了各步的反应热、速度控制步骤的过渡态结构和位能曲线及其相应的反应活化能,计算发现反应机理中的第3步氢转移产物有四员环结构特征.     

基于一维分子线的甲醛分子探针研究

甲醛为公认的致癌物质,本文针对目前甲醛分析需使用专用仪器和试剂盒的不便现状,合成了分子探针(km2bn),通过晶体结构分析发现其苯并二氮杂卓基团与水自组装为一维分子线材料(km2bn·H2O),可与甲醛分子发生固-气相Hantzsch反应,生成具有更大共轭体系二氢吡啶杂环结构,双官能团反应使其生成一维伸展的线性聚合物,共轭体系得到更大的拓展,具有深色与光谱红移效应,其颜色坐标与甲醛浓度具有线性关系,兼具检测选择性,因而可通过该可视显色反应检测甲醛,并可制成试纸,方便普通家庭使用。     

Novel Molecular Resist Based on a First Generation Dendrimer Possessing Furan Rings

Summary: A novel chemically amplified negative‐tone molecular resist for electron‐beam (EB) lithography was developed. The base matrix had six furan rings as a reactive functional group at its terminal. The resist containing the matrix, a crosslinker and a photoacid generator worked well as a negative‐tone resist with high sensitivity (3 µC · cm⁻²). Line and space patterns (1:2) of 200 nm could be fabricated.

SEM image of negative‐tone line and space patterns for the resist film formulated with G1‐dendrimer 5 .     

First Principle Study of Ferromagnetism in Cr-Doped In2O3

We present a first principle study of Cr-doped In2O3 system using density functional theory. The obtained results show that the Cr ion prefers the cation site of the center of trigonally distorted octahedron and converges to high spin-polarized configuration in the ground state. The hybridization between d-states and the donor states is strong, and the spin-split donor impurity-band model is found to be the most favorable mechanism for the ferromagnetism in this system. The good ferromagnetic property of high Curie temperature is discussed in view of the electronic structure analyses.     

近红外漫反射一阶导数光谱法作安体舒通质量控制研究

研究了近红外漫反射一阶导数光谱法作安休舒通粉末药品质量控制的可能性，用多变量统计分类技术，从安体舒通粉末药品的近红外漫反射一阶导数光谱，成功地鉴别了真，劣和假药，结果令人满意。     

一阶导数吸光光度法直接测定饮用水中镁

研究了以甲基百里香酚蓝（MTB）作显色剂,在pH作10.0的NH4Cl-氨缓冲溶液中,用一阶导数吸光光度法测定饮用水中镁的最佳条件。以617nm波长处的零－谷导数值定量,用零交技术可消除钙等干扰。线性范围为0－15μg/25ml,加标回收率在98％－107％之间。经过对饮用水样的测定,并与其它分析方法比较,结果满意。     

一阶导数差示脉冲极谱法用于扑热息痛的定量分析

一阶导数差示脉冲极谱法用于扑热息痛及其制剂的定量分析，在乙醇－水－２．０×１０＾－＾３ｍｏｌ／ＬＨ２ＳＯ４（１２．５：１１．５：１）的溶液中，于０．２４Ｖ（ｕｓＡｇ／ＡｇＣｌ）处出现良好的一阶导数差示脉冲极谱峰，在３．３×１０＾－＾４～３．３×１０＾－＾３ｍｏｌ／Ｌ范围内，浓度与其一阶导数差示脉冲极谱峰值呈线性关系，检测限为７．８×１０＾－＾８ｍｏｌ／Ｌ。方法简便，快速，灵敏，结果准确。     

一阶导数差示脉冲极谱法用于甲硝唑的定量研究

本实验运用一阶导数差示脉冲极谱法对甲硝唑及其制剂进行了定量研究。在０．００１ｍｏｌ／Ｌ氯化钾－０．００１ｍｏｌ／Ｌ盐酸－水（１＋０．２＋４８）的底液中，甲硝唑于－０．８００Ｖ（ｖｓ Ａｇ／ＡｇＣｌ）处出现一良好的一阶导数差示脉冲极谱峰，在５０～３００μｇ／ｍＬ范围内，药物浓度与其导数峰幅值呈线关系，检测限为８．０×１０＾－８ｍｏｌ／Ｌ。本法操作简便，快速，灵敏，结果准确。