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1.
研究了中性芳烃烯土配合物Ln(η^6-C6H6)(AlCl4)3(Ln=La,Nd)对苯烷基化反应的催化作用。Ln(η^6-C6H6)(AlC4)3可在温和条件下催化苯与己烯反应给出正己基苯和仲己基苯。探讨了不同催化剂及反应条件对此反应的影响。  相似文献   

2.
用INDO系列方法对由(C59N)2和苯甲醚合成的衍生物C59(C6H4OCH3)N进行了理论研究,得到了分子的稳定构型。结果表明,C59(C6H4OCH3)N具有Cs对称性,以优化构型为基础讨论了分子的UV-Vis光谱、NMR谱线数,结果与实验符合得很好,本文还计算了C59(C6H4OCH3)N的二阶非线性光学系数βμ,结果表明这种物质具有较大的二阶非线性光学系数。  相似文献   

3.
金宏威  封继康 《结构化学》1999,18(6):451-455
用INDO系列方法对由(C59N)2和甲苯合成的衍生物C59(C6H4CH3)N进行了理论研究,得到了分子的稳定构型,表明C59(C6H4CH3)N具有Cs对称性。以优化构型为基础讨论了分子的UV-VIS光谱、NMR谱,结果瑟实验符合得很好。还计算了C59-(C6H4CH3)N的二阶非线性光学系数βμ,结果表明这种分子具有较大的二阶非线性光学系数。  相似文献   

4.
SynthesisandCrystalStructureofNeodymiumComplex[Nd(C_6H_4OHCHNC_2H_4NCHC_6H_4OH)(NO_3)_3(CH_3SOCH_3)]ZHANGMin;KONGFan-Rong;ZHUHui-J...  相似文献   

5.
SynthesisandCrystalStructureof[Na(DB18C6)(CH_3OH)]_2Mo_6O_(19)·(DB18C6)·(CH_3OH)¥ZhouYin-Zhuang;TuShu-Jie;JinXiang-Lin;LiuShun-...  相似文献   

6.
RE[CH2(CH2)4CONC4H9]3(NO3)3(RE=La,Dy)的合成和晶体结构   总被引:1,自引:0,他引:1  
采用X-射线四园衍射仪测定了Dy「Ch2(CH2)4CONC4H9」3(NO3)3和La「CH2(CH2)4CONC4H3」3(NO3)3的晶体结构。两个配合物具有相似的结构,均属单斜晶系,空间群为P21/c。晶体参数:Dy「La」:a=1.8564(3)「1.8564(2)」nm,b=0.9769(2)「0.9834(1)」nm,c=2.1863(6)「2.20038(7)」nm,β=96.08  相似文献   

7.
用INDO 系列方法对由(C59N)2和甲苯合成的衍生物C59 (C6H4CH3)N进行了理论研究,得到了分子的稳定构型,表明C59(C6H4CH3)N具有Cs对称性。以优化构型为基础讨论了分子的UV-VIS光谱、NMR谱,结果与实验符合得很好。还计算了C59-(C6H4CH3)N的二阶非线性光学系数βμ,结果表明这种分子具有较大的二阶非线性光学系数。  相似文献   

8.
CrystalStructureofCalciumComplexwithCyanuricAcidLigand[Ca(C_3H_3N_3O_3-O)(H_2O)_6][(OH)(C_3H_2N_3O_3)]LinZhou-Bin;ChenChang-Zhang;...  相似文献   

9.
用从头计算法在HF/6-31G基组水平上研究了NH4^++NH3→NH3+NH4^+,NH4^++NH2CH3→NH3+NH3CH3^+,NH4^++NH(CH3)2→NH3+3)2^+以及NH3CH3^++NH2CH3→NH2CH3+NH3CH3^+等4个体系的质子传递反应的机理。结果表明:(1)上述质子传递反应均具有双阱型的势能面,质子沿N(1)、N(2)连线直接传递;(2)质子受体分子中的甲  相似文献   

10.
测定了三核苯甲苯酸合物[Fe3O(OBz)6(CH3OH)3](NO3)(CH3OH)2(OBz^-=苯甲酸根)的电子光谱,应用配体场理论和T-S图求得配体场参数10Dq-12457cm^-1,用CNDO/2方法对其简化模型进行了计算。  相似文献   

11.
By reaction of the hexabromoheptasilane MeSi(SiMe(2)SiMeBr(2))(3) (1 a) with H(2)O, H(2)S, NH(3), and H(2)NMe the heptasilaadamantanes MeSi(SiMe(2)SiMeO)(3) (4), MeSi(SiMe(2)SiMeS)(3) (5), MeSi(SiMe(2)SiMeNH)(3) (6 a), and MeSi(SiMe(2)SiMeNMe)(3) (6 b), respectively, were prepared in good to moderate yields. Molecular structures of 4, 5, 6 a, and 6 b were determined by X-ray crystallography. The symmetry of the cages is approximately C(3v), and the geometry around the nitrogen atoms is essentially planar. Ab initio SCF/HF calculations with the 6-31G* basis set confirm these results. Reduction of MeSi(SiMe(2)SitBuBr(2))(3) (1 b) with lithium naphthalenide afforded the heptasilanortricyclene MeSi(SiMe(2)SitBu)(3) (7). The (29)Si NMR spectrum of 7 consists of three signals with chemical shifts that agree closely with values predicted by ab initio calculations. (29)Si INADEQUATE spectra also strongly support the nortricyclene structure. Ab initio SCF/HF calculations were performed for the parent molecule Si(7)H(10), and the ring strain of the cage was estimated as 168.8 kJ mol(-1) by using the homodesmic reaction Si(7)H(10) + 3 Si(2)H(6)-->Si(13)H(28). Compound 1 a also served as the starting material for the preparation of first-generation dendrimer 2 a by reaction with six equivalents of Ph(2)MeSiLi. Subsequent protodearylation with HBr and reaction with (Me(2)PhSi)(2)SiMeK afforded second-generation dendrimer 3. All dendrimers were characterized by multinuclear NMR spectroscopy.  相似文献   

12.
Reactions of a dinuclear metal complex in the form of dirhodium(II) tetra(trifluoroacetate), [Rh(2)(O(2)CCF(3))(4)] (1), with a number of strong N-donor ligands having functional groups rigidly oriented at different directing angles have been found to yield supramolecular architectures of differing complexity. All structures have been established by X-ray crystallography. From reaction of 1 with neutral tris(4'-pyridyl)methylsilane ligand, CH(3)Si(C(5)H(4)N)(3) (L1), a discrete pyramid-shaped hexanuclear complex [[Rh(2)(O(2)CCF(3))(4)](3)CH(3)Si(C(5)H(4)N)(3)(eta(1)-C(6)H(6))(3)].C(6)H(6) (2.C(6)H(6)) has been isolated from benzene. In 2 three molecules of 1 are strongly coordinated to one L1 ligand at only one axial position of each dirhodium unit at the Rh-N distances of 2.152(6) A. The second rhodium atom of each dimetal complex in 2 weakly coordinates a benzene molecule with an Rh-C distance of 2.69(2) A. A supramolecular complex of the composition [[Rh(2)(O(2)CCF(3))(4)](2)(C(6)H(5))(2)Si(C(5)H(4)N)(2)] (3) has been prepared by reacting the dinuclear units 1 with a potentially bidentate ligand, bis(4'-pyridyl)diphenylsilane, (C(6)H(5))(2)Si(C(5)H(4)N)(2) (L2), having two pyridyl groups rigidly oriented at 109 degrees. In 3, one L2 ligand coordinates two dirhodium molecules 1 through their axial positions with the Rh-N distance of 2.150(5) A. An interesting extended 2D layered motif is formed by additional contacts of open axial positions of dirhodium units with phenyl groups of the neighboring ligands at Rh-C distances which average to 2.88(1) A. A supramolecular compound of the composition [[Rh(2)(O(2)CCF(3))(4)](3)(HO)C(C(5)H(4)N)(3)(eta(1)-C(6)H(6))].(1)/(2)C(6)H(6) (4.(1)/(2)C(6)H(6)) has been formed when linear dirhodium units 1 were reacted with tris(4'-pyridyl)methanol (L3) having tetrahedral directing angles that average to 110 degrees. A building block in the solid structure of 4 is a hexanuclear molecule in which one L3 ligand binds three dimetal units of 1 through N atoms of pyridyl groups at the average Rh-N distance of 2.143(7) A. A unique extended pseudo-3D structure in 4 is created by additional Rh-O coordination bonds as well as by weak metal-arene interactions.  相似文献   

13.
An optimized and automated protocol for determining the location of guest sorbate molecules in highly siliceous zeolites from (29)Si INADEQUATE and (1)H/(29)Si cross polarization (CP) magic-angle spinning (MAS) NMR experiments is described. With the peaks in the (29)Si MAS NMR spectrum assigned to the unique Si sites in the zeolite framework by a 2D (29)Si INADEQUATE experiment, the location of the sorbate molecule is found by systematically searching for sorbate locations for which the measured rates of (1)H/(29)Si cross polarization of the different Si sites correlate linearly with (1)H/(29)Si second moments calculated from H-Si distances. Due to the (1)H/(29)Si cross polarization being in the "slow CP regime" for many zeolite-sorbate complexes, it is proposed that the CP rate constants are best measured by (1)H/(29)Si cross polarization drain experiments, if possible, to avoid complications that may arise from fast (1)H and (29)Si T(1)rho relaxations. An algorithm for determining the sorbate molecule location is described in detail. A number of ways to effectively summarize and display the large number of solutions which typically result from a prediction of the structure from the CP MAS NMR data are presented, including estimates of the errors involved in the structure determinations. As a working example throughout this paper, the structure of the low loaded p-dichlorobenzene/ZSM-5 complex is determined under different conditions from solid-state (1)H/(29)Si CP MAS NMR data, and the solutions are shown to be in excellent agreement with the known single-crystal X-ray diffraction structure. This structure determination approach is shown to be quite insensitive to the use of relative rate constants rather than absolute values, to the detailed structure of the zeolite framework, and relatively insensitive to temperature and motions.  相似文献   

14.
A series of tin(II) amido complexes possessing m-terphenyl carboxylate ligands have been prepared. These complexes, namely [(Me(3)Si)(2)NSn(mu-O(2)CC(6)H(2)Ph(3))](2), [(Me(3)Si)(2)NSn(mu-O(2)CC(6)H(3)Mes(2))](2), and [(Me(3)Si)(2)NSn(mu-O(2)CC(6)H(2)Mes(2)Me)](2) [Mes = 2,4,6-trimethylphenyl], are the first structurally characterized examples of tin(II) carboxylate complexes exhibiting discrete Sn(2)O(4)C(2) heterocyclic cores. Initial reactivity studies led to the isolation of a 1,3-diaza-2,4-distannacyclobutanediyl, [(Mes(2)C(6)H(3)CO(2))Sn(mu-NSiMe(3))](2). This molecule possesses a Sn(2)N(2) heterocyclic core and it was crystallised as both the CH(2)Cl(2) and Et(2)O solvates. Although the tin atoms in this molecule have a formal oxidation state of 3+, preliminary computational studies on this molecule suggest that it is best described as a ground state singlet. Finally, the X-ray crystal structure of (CH(2)Cl)(Cl)Sn[N(SiMe(3))(2)](2), the product of oxidative addition of CH(2)Cl(2) to Sn[N(SiMe(3))(2)](2), is also presented herein.  相似文献   

15.
First-principles pseudopotential calculations, within a simple dynamically constrained scheme, have been performed to investigate the reaction of 0.25 ML coverage of SiH4 and Si2H6 with the Si(001)-(2 x 2) surface. The silane molecule (SiH4) is adsorbed on to the surface at a number of different sites (on dimer, interrow, or intrarow) with varying barrier heights. Two distinct structures, which are similar in energy, arise from the initial dissociative reaction SiH4-->SiH3(silyl) + H, where the dissociated species are adsorbed either on the same dimer components or on adjacent dimer components. Several further decays of silyl from SiH4 are presented in two separate regimes of high and low ambient hydrogen coverages. The decomposition of silyl can form two different bridging structures: an on top or an intrarow bridging structure in both of the two hydrogen coverage regimes. The disilane molecule (Si2H6) is also adsorbed upon this surface with varying energy barriers, resulting in a dissociation reaction where two SiH3 species are adsorbed on one dimer or in an adjacent dimer configuration. Plausible energy reaction paths for the above models are presented. The stability of the SiH2 species is also discussed.  相似文献   

16.
Density function theory calculations using B3' exchange functional and LYP' correlation functionals (B3LYP) with the 3-21G** basis set were carried out to study the molecular structure and fundamental vibrational frequencies of Si2H5Br, Si2H5I and their isotopomers. One scale factor used to scale Si-H(D) force constants for Si2H5Br is transferred from Si2H5Br to Si2H5I. Other scale factors of force constants for Si2H5I and Si2D5I are determined by a least-squares fitting to experimental vibrational frequencies. The predictions of fundamental vibrational frequencies for Si2H5I and its isotopomer are given. The scaled DFT force fields using B3LYP/3-21G** reproduced the observed fundamental vibrational frequencies of Si2H5I and its deuterium isotopomer with a mean absolute deviation of 6 cm(-1). Reassignment of some fundamental vibrational modes of Si2H5I and its isotopomer is discussed.  相似文献   

17.
A study has been made of the crystal and molecular structure of 1-hydrosilatrane HSi(OCH2CH2)3N. The quantum chemical calculations of its crystal structure have been carried out. According to an estimate of the energy, the coordination bond N→Si is by 5 kcal mol?1 stronger than that in the crystal of 1-methylsilatrane. The charge values calculated within the framework of the topological analysis of the electron density demonstrate that the electron density of the coordination bond N→Si is primarily transferred to the region of the equatorial bonds Si—O and, to a lesser extent, to the bond Si—H. On going from the isolated molecule of 1-hydrosilatrane to its crystal, the interatomic distance N—Si decreases, mainly owing to the weak intermolecular interaction C—H...O.  相似文献   

18.
将含氮硅烷与正硅酸乙酯进行对比,研究了它们对端羟基聚二甲基硅氧烷(HTPDMS)缩合固化形成的涂膜表面疏水性的影响,发现固化剂NH2(CH2)3Si(OC2H)3使涂膜疏水性明显下降.用ESCA和相差显微镜等方法证明了这种现象是由于NH2(CH2)3Si(OC2H5)3自身固化产生的分相性引起的.  相似文献   

19.
Metathesis between [(Me3Si)2CH)(C6H4-2-OMe)P]K and SmI2(THF)2 in THF yields [([Me3Si]2CH)(C6H4-2-OMe)P)2Sm(DME)(THF)] (1), after recrystallization. A similar reaction between [(Me3Si)2CH)(C6H3-2-OMe-3-Me)P]K and SmI2(THF)2 yields [([Me3Si]2CH)(C6H3-2-OMe-3-Me)P)2Sm(DME)].Et2O (2), while reaction between [(Me3Si)2CH)(C6H4-2-CH2NMe2)P]K and either SmI2(THF)2 or YbI2 yields the five-coordinate complex [([Me3Si]2CH)(C6H4-2-CH2NMe2)P)2Sm(THF)] (3) or the solvent-free complex [([Me3Si]2CH)(C6H4-2-CH2NMe2)P)2Yb] (4), respectively. X-ray crystallography shows that complex 2 adopts a distorted cis octahedral geometry, while complex 1 adopts a distorted pentagonal bipyramidal geometry (1, triclinic, P1, a = 11.0625(9) A, b = 15.924(6) A, c = 17.2104(14) A, alpha = 72.327(2) degrees, beta = 83.934(2) degrees, gamma = 79.556(2) degrees, Z = 2; 2, monoclinic, P2(1), a = 13.176(4) A, b = 13.080(4) A, c = 14.546(4) A, beta = 95.363(6) degrees, Z = 2). Complex 3 crystallizes as monomers with a square pyramidal geometry at Sm and exhibits short contacts between Sm and the ipso-carbon atoms of the ligands (3, monoclinic, C2/c, a = 14.9880(17) A, b = 13.0528(15) A, c = 24.330(3) A, beta = 104.507(2) degrees, Z = 4). Whereas preliminary X-ray crystallographic data for 4 indicate a monomeric structure in the solid state, variable-temperature 1H, 13C(1H), 31P(1H), and 171Yb NMR spectroscopies suggest that 4 undergoes an unusual dynamic process in solution, which is ascribed to a monomer-dimer equilibrium in which exchange of the bridging and terminal phosphide groups may be frozen out at low temperature.  相似文献   

20.
四羰基二(五甲二硅基环戊二烯基)二钼的合成及反应   总被引:3,自引:0,他引:3  
邝代治  周秀中 《化学学报》1994,52(9):853-857
本文进一步报道四羰基二(五甲二硅基环戊二烯基)二铜的合成及反应, 五甲二硅基环戊二烯与六羰基钼在甲苯中加热回流9h, 即生成含Mo-Mo键的双核钼配合物1, 1在甲苯中进一步加热回流, 则发生脱羰而生成标题化合物。  相似文献   

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