C60与硅烯环加成反应机理的理论研究

用半经验AM1法研究了C₆₀与单态硅烯环加成反应机理.经Berny梯度法优化得到反应的过渡态,并进行了振动分析确认.计算结果表明:硅烯在C₆₀的66键上的加成反应分两步,第一步反应物生成中间配合物,无势垒;第二步由中间配合物经过渡态变为产物.65键上的加成反应分三步,第一步由反应物生成中间配合物,第二步由中间配合物经过渡态I得到闭环结构的中间体,第三步由中间体经过渡态Ⅱ形成产物.66键加成反应的活化势垒较低,从反应机理和动力学角度解释了66键加成优于65键加成的原因.     

光催化硅氢加成反应研究进展

有机硅产品已成为我们生活中不可或缺的一部分.催化硅氢加成反应是制备有机硅化学品和材料的重要方法,廉价而性能优异的催化剂研制和开发受到广泛关注.目前催化硅氢加成的研究还主要集中在探索新型贵金属和非贵金属配合物的催化性能,但受贵金属高成本和非贵金属配合物较低催化活性等限制,光催化作为一种环保、安全的催化方式,光催化硅氢加成反应受到重视.介绍了近年来光催化硅氢加成反应的研究进展.     

过渡金属膦配合物在硅氢化反应中的应用研究

过渡金属膦配合物在有机合成和催化反应中的应用非常广泛, 大量含膦杂原子配体被设计合成, 利用其特定的配位能力, 和过渡金属配位成过渡金属膦配合物, 并测试其对特定有机化学反应的催化性能. 硅氢加成反应是有机硅化学中的重要反应, 多种过渡金属包括铂、钯、铑、钌等的膦配合物对于硅氢加成反应均有催化活性. 综述了近几年来过渡金属膦配合物在硅氢加成反应中的应用进展.     

新型共价键连的富勒烯-卟啉化合物的合成与表征

为了构造一个具有有效电荷转移的给-受体体系,通过1,3-偶极加成反应,由5-[2-'(4″-醛基苯氧丙氧苯基)]-10,15,20-三苯基卟啉(H₂P-CHO)、肌氨酸和C₆₀首次合成了一种新的以共价键相连的富勒烯-卟啉配体(H₂P-C₆₀),同时用该配体制备了其锌配合物(ZnP-C₆₀),并用红外光谱、元素分析、电子光谱、核磁共振氢谱和质谱等方法进行了表征.     

过渡金属钌、铑配合物在室温离子液体中催化硅氢加成反应的研究

研究了在室温离子液体以及室温离子液体/有机溶剂复合介质体系中, Rh(PPh₃)₃Cl, Ru(PPh₃)₃Cl₂等催化烯烃与三乙氧基硅烷的硅氢加成反应. 实验结果表明, 在乙二醇二甲醚/离子液体1-丁基-3-甲基咪唑六氟磷酸盐(BMImBF₆) (V/V＝1/4)介质中, 于90 ℃下, 己烯与三乙氧基硅烷反应的转化率为100%, β加成物的选择性可达89.0%. 而用Rh(PPh₃)₃Cl作为反应的催化剂, 在纯离子液体BMImPF₆中, 就可以高效催化烯烃与三乙氧基氢硅烷的加成反应. 过渡金属Rh(PPh₃)₃Cl, Ru(PPh₃)₃Cl₂催化剂/离子液体BMImPF₆催化体系, 不仅解决了产物与催化剂分离困难这一难题, 同时, 离子液体BMImPF₆的存在提高了过渡金属Rh(PPh₃)₃Cl, Ru(PPh₃)₃Cl₂催化硅氢加成反应的活性, 特别是β加成物的选择性. 反应结束后, 催化剂/离子液体与产物易于分离, 并且可以重复使用.     

聚-4,7-二硫杂癸烯-9-基倍半硅氧烷铑配合物的合成及其对烯烃硅氢加成的催化性能

本文报道一种新型高效烯烃硅氢加成催化剂—聚-4,7-二硫杂癸烯-9-基倍半硅氧烷铑配合物的合成、结构表征及其对烯烃硅氢加成反应的催化性能。在该配合物存在下,癸烯与三乙氧基硅烷的硅氢加成反应平稳地进行,烯烃的转化数达到80,000。     

C40H2各种可能异构体稳定性的理论研究

采用AM1和PM3两种半经验方法,对D_5d对称性的C₄₀及C₄₀H₂所有可能异构体的几何构型进行了非限制对称性全优化,得到51种稳定异构体,在此基础上研究了氢的加成反应规律及本体C₄₀和最稳定及最不稳定C₄₀H₂异构体的红外光谱,讨论了影响C₄₀(D_5d)氢加成异构体稳定性及加成位置选择性的三种主要因素:(1)C₄₀本体几何结构;(2)共轭效应;(3)电荷分布影响.     

中间体C60(CH3)-和产物C60(CH3)2的结构及产物

用INDO系列方法对C₆₀^2-与CH₃反应的中间体C₆₀(CH₃)^-进行理论研究,得到具有Cs对称性的构型。结果表明,CH₃加成到C₁₅上,将使与其相邻的双键碳(C₃₀)的电荷密度和自旋密度达极大值,故加成反应部位在C₃₀处;另外,C₁₅的对位C₁₂(或C₂₇)也较其它部位易于反应,且有两个反应场所,因而产物C₆₀(CH₃)₂可能为六元环上的1,2-加成和1,4-加成两种异构体的混合物。同时对两种加成产物的结构和电子光谱进行了理论研究,指认其电子跃迁,并讨论了其光谱红移的原因。     

侧基上带有C60基团的聚苯乙烯的表征

用UV、FTIk、DSC、TG和DTA及GPC等方法证明了通过三步反应(氯甲基化,叠氮化,环加成反应)确实将C₆₀引入到聚苯乙烯的侧基上,C₆₀基本上以单取代的方式存在,并通过TG和DTA方法估算了C₆₀在聚苯乙烯C₆₀衍生物中的含量。     

大取代茂锆配合物合成及分子内消除反应研究

通过6,6-二烷基富烯与2-MeOArLi进行加成反应, 得到含芳氧取代的环戊二烯基锂盐, 再与取代茂三氯化锆反应, 合成了不对称大位阻取代茂锆配合物RCpCp^oZrCl₂ [Cp^o＝2-MeOArCR¹R²Cp, R¹, R²＝CH₃, C₂H₅, (CH₂)₅, etc.], 所得的配合物均通过¹H NMR, IR, MS和EA鉴定. 在此过程中发现该类配合物能进行分子内消除反应, 脱去苯甲醚得到烯基取代的二氯二茂锆配合物, 该反应为未见文献报道的新反应, 对该反应进行了研究.     

Specific features of the structure of a lanthanum nitrate complex with ethylenediamine

Anhydrous lanthanum nitrate and its complexes with one and two ethylenediamine molecules are calculated by the ab initio B3LYP/LANL2DZ quantum-chemical method. An ethylenediamine molecule is shown to coordinate preferentially through one amino group, and a hydrogen bond is formed between the coordinated amino and nitrato groups. An ethylenediamine complex of lanthanum nitrate is synthesized, and its composition and thermal stability are determined. The IR spectra of the ethylenediamine complex of lanthanum nitrate confirm the presence of the intramolecular hydrogen bond in this complex.     

Ligand Substitution Reaction of Bis(ethylenediamine)glycinatocobalt(III) Complex with Ethylenediamine Catalyzed by the Photo-excited Tris(2,2′-bipyridine)ruthenium(II) Complex

Substitution reaction with ethylenediamine of coordinated glycinate ligand in bis(ethylenediamine)-glycinatocobalt(III) complex has been studied in the presence of photo-excited tris(2,2′-bipyridine)ruthenium(II) complex in alkaline aqueous solution (buffered around pH 12) containing 1.0M chloride ion at 25°C. VIS absorption and CD spectra were used for the racemate and the optically active isomers of the Co(III) complexes, respectively. The reaction was catalyzed by the excited Ru(II) complex to give tris(ethylenediamine)cobalt(III) complex. Mechanism of the ligand-substitution reaction and role of the excited Ru(II) complex were discussed.     

Complex of Copper(II) with Ethylenediamine and Decyl Sulfate Ions. Formation in Water and Crystal Structure

Decyl sulfate ions form strong associates with ethylenediammonium cations and copper(II) ethylenediamine complexes. A solid compound of the composition copper(II):ethylenediamine:decyl sulfate ion = 1:2:2 was isolated from the aqueous solution; its crystal structure was studied to find that it comprises a regular combination of formula units of an inner-sphere complex bis(ethylenediamine)bis(decyl sulfato)copper(II) and a complex associate of two decyl sulfate ions with diaquabis(ethyenediamine)copper(II).     

Synthesis of new polymetallic carbene complexes: Uracil analogs

The easy cycloaddition of ureas with alkynyl alkoxy biscarbene complexes afforded, in fairly good yields, new biscarbene uracil analogs. X-ray structural data is reported for the dimethyluracil biscarbene complex. By changing the reaction conditions, a new non symmetric complex was obtained whose reaction with ethylenediamine afforded a new tetrakis amino carbene complex.     

纤维素乙二胺负载钯配合物的制备及其对Heck反应的催化性能

合成了纤维素乙二胺负载钯（CE—Pd）配合物,用IR、XPS、TG／DTA等手段对其进行了表征．该配合物在室温至280oC范围内有很好的稳定性,在空气氛围水相中能有效地催化丙烯酸与芳基碘、苯乙烯与芳基碘的Heck芳基化反应,立体选择性地生成取代的反式肉桂酸、1,2-二苯乙烯．在80℃时反应6h,反式肉桂酸的产率达89．7％．纤维素乙二胺负载钯（CE—Pd）配合物还具有较好的重复使用性能,连续使用4次,反式肉桂酸的产率仍可达到63．5％．     

Unique reactivity of a tetradentate N(2)S(2) complex of nickel: intermediates in the production of sulfur oxygenates

Complex 1 [(N,N'-dimethyl-N,N'-bis(2-sulfanylethyl)ethylenediamine)nickel(II)], previously shown to react with H(2)O(2) to produce the fully oxygenated disulfonate 5 [diaqua(N,N'-dimethyl-N,N'-bis(2-sulfonatoethyl)ethylenediamine)nickel(II)], has been explored in detail to explain the observed reactivity of this compound and to discern intermediates in the oxygenation reaction. Reaction of 1 with 1 equiv of methyl iodide results in the monomethylated square-planar nickel complex 2 [[(N,N'-dimethyl-N-(2-sulfanylethyl)-N'-(2-methylthioethyl)(ethylenediamine)nickel(II)] iodide], while a slight excess of methyl iodide results in the dimethylated complex 3 [diiodo(N,N'-dimethyl-N,N'-bis(2-methylthioethyl)ethylenediamine)nickel(II)], an X-ray structure of which has shown that the nickel ion is in an octahedral N(2)S(2)I(2) environment. Crystal data of 3: monoclinic, a = 8.865(3) A, b = 14.419(4) A, c = 14.389(6) A, beta = 100.19(3) degrees, V = 1810.2(12) A(3), space group P2(1)/n, Z = 4. The equatorial positions are occupied by the two cis-amine N-atoms and the coordinated iodides, while the axial positions are occupied by the thioether sulfur atoms. In organic solvents, the dithiolate complex 1 reacts with molecular oxygen or H(2)O(2) to produce the mixed sulfinato/thiolato complex 4 [(N,N'-dimethyl-N-(2-sulfanylethyl)-N'-(2-sulfinatoethyl)(ethylenediamine)nickel(II)], and the fully oxidized product 5. X-ray analysis of complex 4 reveals a square-planar geometry in which the nickel ion is coordinated by two cis-amine nitrogens, one thiolate sulfur donor, and one sulfinato sulfur donor. Crystal data of 4: orthorhombic, a = 11.659(2) A, b = 13.119(3) A, c = 16.869(3) A, V = 2580.2(9) A(3), space group Pbca, Z = 8. This complex is the only intermediate in the oxygenation reaction that could be isolated, and it is shown to be further reactive toward O(2) to yield the fully oxidized product 5. For a better understanding of the reactivity observed for 4, DFT calculations have been undertaken, which show a possible reaction path toward the fully oxidized product 5.     

The thermal behaviour of some Co(II) complex combinations with schiff bases

In order to evidence the ligand influence on the thermal stability for Co(II) complex combinations, we have synthesized five complex combinations of this metal with Schiff bases obtained by condensation of ethylenediamine with acetylacetone and benzoylacetone; phenylenediamine with benzoylacetone and also anthranilic acid with benzaldehyde. This revised version was published online in July 2006 with corrections to the Cover Date.     

Synthesis and Molecular Structure of Bis(ethylenediamine)acetatonickel(II)hexafluoridophosphate Complex [Ni(en)2(CH3CO2)]PF6. An Unexpected Acetylacetonato Cleavage Reaction

The title complex was synthesized by an unusual reaction between [Ni(acac)₂(H₂O)₂] and ethylenediamine in water solution. The crystal structure of 1 shows the nickel(II) core in a tetragonally distorted octahedral environment coordinated to two ethylenediamine molecules and one acetate ligand. This is the first example of a mononuclear bis(ethylenediamine)nickel(II) complex, where the oxygen atoms of the auxiliary ligand are in cis configuration. The compound exhibits an extensive association between the complex cation and the respective anion through classical N–H ··· O and N–H ··· F intermolecular hydrogen bonds, which generate a supramolecular 3D arrangement in the solid state.     

Extended ensemble molecular dynamics study of cellulose I–ethylenediamine complex crystal models: atomistic picture of desorption behaviors of ethylenediamine

Cellulose - Cellulose I crystals swell on exposure to ethylenediamine (EDA) molecules to form a cellulose I–EDA complex, and successive extraction of EDA molecules converts the complex...     

Ruthenium(II)-catalyzed transfer hydrogenation of aldehydes with new water-soluble monotosylated ethylenediamines as ligands

New water-soluble monotosylated ethylenediamines containing quaternary ammonium groups were conveniently synthesized from ethylenediamine. The ruthenium catalysts prepared in situ from ruthenium complex [RuCl₂(p-cymene)]₂ and water-soluble monotosylated ethylenediamine ligands were used in transfer hydrogenation of aldehydes, and excellent conversions and chemoselectivities were achieved with sodium formate as reductant in neat water.