Chemical microenvironment mediated formation of organic nanostructures from self-assembly of melamine and barbituric acid derivatives

The recent progresses on constructing organic nanostructures from the self-assembly of melamine and barbituric acid derivatives are reviewed. By mediating the chemical microenviron-ment during the self-assembly, the information contained in the molecular components can be expressed at different levels, thus resulting in the formation of different organic nanostructures. When the assembly is carried out in anhydrous chloroform, a kind of asymmetric layered structure with a d value of 4.1 nm is obtained. When a little amount of polar solvent such as alcohol is contained in the chloroform, organic nanotubes with diameter of 6 nm and length of several hundreds of nanometers are observed. After being treated by appropriate polar solvents, the nanotubes are induced into supercoils with diameter of about 300 nm and length of several tens of microns. The sensitivity of the self-assembly process origins from the weak noncovalent intermolecular interactions between the molecular components. The enthalpy change of     

全反式球形烯的光敏异构化及异构体的光谱

从Rhodobacter sphaeroides 2.4.1提取了全反式球形烯, 用高压液相色谱(HPLC)分离了它的I2增感异构化产物: 9,13'-cis(峰A), 5,13-cis+13,9'-cis(峰B), 13-cis(峰C), 5,13'-cis(峰E1), 9-cis(峰E2), 13'-cis(峰F),5,9'-cis(峰G), 9'-cis(峰H), all-trans(峰I), 研究了异构体的结构对其电子吸收光谱及HPLC保留时间的影响, 从而确认峰E1为5,13'-cis。对全反式球形烯的光敏异构化机理也作了初步探讨。     

SnO2超微粒薄膜上醇的催化氧化

等离子体化学气相沉积(PCVD)法可制备多孔柱状结构的SnO_2超微粒非晶薄膜,本文研究了薄膜在真空吸附体系中的膜电阻和IR谱随温度变化特性及乙二醇、正丙醇、异丙醇、乙醇和甲醇的气敏灵敏度,提出SnO_2薄膜上吸附氧O_2~-、O~-对醇的氧化机理 1实验与结果 自制PCVD装置抽空后充入40 Pa的O_2,加高频出现辉光,再充入CnCl_4使辉光转为蓝     

Frontier orbital interactions of electron pushing and drawing substituents with ferrocenyl group

The frontier orbital interactions of electron pushing and drawing substituents with ferrocenyl group were analyzed based on the electrochemical,UV visible spectral and spectroelectrochemical results of five ferrocene derivatives,R-Fc-A1(PⅠ),A1-Fc-A1(PⅡ),D-Fc-R (PⅢ),D-Kc-A1(PIV) and D-Fc-A2(PV)(R,CH2OH;A1 CHO;A2,CH=C(CN)2 and D,(C18H37)2N-C6H4-CH=CH) It was found that there are strong interactions of the LUMO (πA) of electron drawing substituents with le2g(dxy,dx2 y2)and e2u of the ferroeenyl group because the energy levels of πA and e2g,C2U of (Cp )2 are close,which lower not only the energy levels of bonded orbits,πA+ and dx2-y2+[πA] of PⅠ,PⅡ,PⅣ and PⅤobviously,but also those of their non-bonded orbu dxy For PⅢ,PⅣ and PⅤ,there are strong interactions of HOMO(πD) of the electron pushing substituent with le of the ferrocenyl group because the levels of πD and e of (Cp)2 are close,which result in the formation of anti-bonded orbit,πD- and bonded orbit     

推拉电子取代基对二茂铁衍生物性质及电子结构的影响

根据前线轨道理论分析３种具有推拉电子取代基的二茂铁衍生物循环伏安曲线、电子吸收光谱及光谱电化学行为，并给出了分子轨道能级图，实验结果表明，ＰⅡ有两对可逆氧化还原峰，Ｅ１、Ｅ２分别为０．３３、０．５９Ｖ，第一氧化态ＰⅡ＋￣（Ｄ—Ｆｃ￣＋—Ｒ）在６１３ｎｍ有强的ＬＭＣＴ（ｌｉｇａｎｄ－ｔｏ－ｍｅｔａｌ－ｃｈａｒｇｅ－ｔｒａｎｓｆｅｒ）带，是一种良好的光学特性氧化还原开关．ＰⅡ在３５４ｎｍ处出现强的ＬＭＣＴ带，ＰⅢ在３５６ｎｍ和３２０ｎｍ处分别出现强的ＬＭＣＴ和π→πＣＴ带，应具有较高的二阶分子极化系数，应当是较好的ＳＨＧ材料．