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1.
仇毅翔  王曙光 《化学学报》2006,64(14):1416-1422
采用从头计算HF, MP2方法和密度泛函理论, 对Au(II)系列化合物[Au(CH2)2PH2]2X2 (X=F, Cl, Br, I)的几何结构、电子结构和振动频率进行了研究. 研究表明Au的5d和6s电子参与Au—Au以及Au—X之间的成键. Au—Au, Au—X键强烈的电子相关作用使HF方法不适于该体系的研究, BP86和B3LYP两种泛函给出较大的Au—Au和Au—X键长, 而MP2方法和局域的密度泛函方法则给出了合理的结构参数. 局域密度泛函方法计算得到的Au—Au键和 Au—X键振动频率也与实验数据符合较好. 还运用含时密度泛函理论计算了[Au(CH2)2PH2]2X2的电子激发能, 对分子在紫外-可见光谱范围内的电子跃迁进行了分析, 考察了卤素配体对激发能的影响, 并结合分子轨道能级的变化对此给予了解释.  相似文献   

2.
采用从头计算HF, MP2方法和密度泛函理论, 对Au(II)系列化合物[Au(CH2)2PH2]2X2 (X=F, Cl, Br, I)的几何结构、电子结构和振动频率进行了研究. 研究表明Au的5d和6s电子参与Au—Au以及Au—X之间的成键. Au—Au, Au—X键强烈的电子相关作用使HF方法不适于该体系的研究, BP86和B3LYP两种泛函给出较大的Au—Au和Au—X键长, 而MP2方法和局域的密度泛函方法则给出了合理的结构参数. 局域密度泛函方法计算得到的Au—Au键和 Au—X键振动频率也与实验数据符合较好. 还运用含时密度泛函理论计算了[Au(CH2)2PH2]2X2的电子激发能, 对分子在紫外-可见光谱范围内的电子跃迁进行了分析, 考察了卤素配体对激发能的影响, 并结合分子轨道能级的变化对此给予了解释.  相似文献   

3.
The synthesis and characterization of platinum(II) and palladium(II) complexes of the type [PtX2( n Pr-N(Ph2P)2)] (X = Cl, I) and [PdCl2(R-N(Ph2P)2)] {R =  n Pr, p-OMe(C6H4)} containing aminodiphosphine P,P-bidentate ligands is described. Complexes of the type [PtCl2(R-N(Ph2P)2)] (where R = benzyl, 2-picolyl and n Pr) catalyzed the hydroformylation of 1-octene, albeit at low activities and slightly elevated regioselectivities toward the linear aldehyde, when compared with analogous compounds containing small bite angles.  相似文献   

4.
An efficient and short synthesis of (2R,3R)- and (2S,3S)-β-hydroxyornithine 1a-b is described using Sharpless asymmetric dihydroxylation and regioselective nucleophilic opening of a cyclic sulfite as the key steps.  相似文献   

5.
Diphenylphosphanyl malononitrile, Ph2P-CH(CN)2 (1) reacts with Cp2TiCl in the presence of triethylamine in THF to give air sensitive Ti(III) complex [μ2(N,N′)-Ph2PC(CN)2TiCp2]2 (2), which is centrosymmetric dimer in the solid state, containing nearly planar 12-member metallocycle. Solution of 2 (200 K) exhibits anisotropic EPR spectrum; every spectral component contains splitting on a single phosphorus nucleus.  相似文献   

6.
The title dimanganese complexes react with NO (5% in N2) at room temperature to give as major products the corresponding hexanitrosyl derivatives [Mn2(NO)6(μ-L2)] in moderate yields, and they react rapidly with NO2 to give the corresponding hydride derivatives [Mn2(μ-H)(μ-NO2)(CO)6(μ-L2)], these having a nitrite ligand bridging the dimetal centre through the N and O atoms. The dppm-bridged dihydride also reacts selectively at 273 K with (PPN)NO2 to give first the nitro derivative (PPN)[Mn2(μ-H)(H)(NO2)(CO)6(μ-dppm)], which then transforms into the nitrosyl complex (PPN)[Mn2(μ-CO)(CO)5(NO)(μ-dppm)] at room temperature or above (dppm = Ph2PCH2PPh2; PPN+ = [N(PPh3)2]+). The latter anion reacts with (NH4)PF6 to give the hydride-bridged nitrosyl complex [Mn2(μ-H)(μ-NO)(CO)6(μ-dppm)] and with [AuCl(PPh3)] to give the trinuclear cluster [AuMn2(μ-NO)(CO)6(μ-dppm)(PPh3)] (Mn-Au = ca. 2.68 Å; Mn-Mn = 2.879(2) Å). Both products are derived from the addition of the added electrophile at the intermetallic bond and rearrangement of the nitrosyl ligand into a bridging position. In contrast, methylation of the anion with CF3SO3Me takes place at the nitrosyl ligand to yield the unstable methoxylimide derivative [Mn2(μ-NOMe)(CO)6(μ-dppm)]. Analogous reactions at the nitrosyl ligand take place upon the addition of HBF4·OEt2 to the nitrosyl-bridged hydrides [Mn2(μ-H)(μ-NO)(CO)n(μ-dppm)m] (n = 6, m = 1; n = 4, m = 2) to give the corresponding hydroxylimide derivatives [Mn2(μ-H)(μ-NOH)(CO)n(μ-dppm)m]BF4, which were also thermally unstable and could not be isolated nor fully characterized.  相似文献   

7.
Reaction of tin tetrachloride with the appropriate Grignard reagent gave Sn[C6H4-CH(OCH2)2]4 (2), which was transformed to Sn[C6H4-CHO]4 (3) and its hydrazido and amino derivatives Sn[C6H4-CHN-NH-C6H3-2,4-(NO2)2]4 (5) and Sn{C6H4-CH[N(C2H4)2O]2}4 (8). Oxidation of (3) produced Sn[C6H4-COOH]4 (4) while reduction of (3) gave Sn[C6H4-CH2-OH]4 (6). From the acid 4, an amino acid Sn[C6H4-CO-NH-CH2-CO-OCH3]4 (7) could be obtained by reaction with the methyl ester of glycine. All compounds were isolated in pure form with yields of 40-64% and were characterised by spectroscopic means (heteronuclear NMR) or by X-ray structure determination (3).  相似文献   

8.
Preparation of the following new m-SF5CF2CF2C6H4X derivatives has been achieved: X=N3(2), Br(3), OC(O)CHCH2(4), CHCH2(5). The compounds were characterized by their respective IR, NMR, mass spectra (MS) and high resolution mass spectrometry (HRMS). An improved yield of SF5(CF2)2C6H5 (1) is also reported along with the synthesis of the polyacrylate (6) and polystyrene (7) from their respective monomers.  相似文献   

9.
A procedure for the synthesis of the heteropolymetallic germanium(IV) and copper(II) complex with trihydroxyglutaric acid (H5Thgl) [Cu(H2O)6][Ge(μ3-Thgl)2{Cu(H2O)2}2] · 2H2O (I) was developed and the complex was isolated for the first time in the solid state. The product was characterized by elemental analysis, powder X-ray diffraction, thermogravimetry, and IR spectroscopy. Compound I was studied by X-ray crystallography. The crystals are monoclinic, a = 10.216(2)?, b = 12.272(3)?, c = 10.679(2)?, β = 93.13(3)°, V = 1336.9(5)?3, Z = 2, space group P21/n, R1 = 0.0261 for 3616 reflections with I > 2σ(I). Compound I is composed of bimetallic [Ge(μ3-Thgl)2{Cu(H2O)2}2]2− anions, [Cu(H2O)6]2+ cations, and water molecules of crystallization. In the centrosymmetric trinuclear complex anion, the Ge(1) atom is bound by two fully deprotonated bridging ligands to two Cu atoms. The Ge(1) atom is coordinated at distorted octahedron vertices by six hydroxyl oxygen atoms of two Thgl5− ligands (average Ge(1)-O distance is 1.8874(13)?). The Cu coordination polyhedron in the anion is an extended square pyramid (4 + 1) formed by the bridging hydroxyl oxygen atom (Cu(1)-O(3), 2.0039(12) ?), two carboxyl oxygen atoms (average CU(1)-O distance is 1.9674(14)?) of two Thgl5− ligands, and two water oxygen atoms in equatorial and axial positions (Cu(1)-O, 1.9761(13) and 2.3643(14)?, respectively). In the centrosymmetric cation, the Cu coordination polyhedron is an extended square bipyramid (4 + 2). The equatorial Cu-O bond length is 1.9428(14) ? (average), the axial Cu-O bond is elongated to 2.5151(14)?. The cations and anions are combined by H-bonds.  相似文献   

10.
The complex compound of copper(II) nitrate with 1ethyltetrazole (ettz), Cu( C3H6N4)2(NO3)(NO3)2/2] is studied by Xray diffraction analysis (“Syntex P21” automatic diffractometer, CuKa radiation, graphite monochromator, 6/26 scan mode with Vmin = 3.91 deg/min, the total number of data collected 3544 lhkb including 3141 nonextinct lhkl > 0, a correction for absorption (Μ = 25.08 cm-1) applied by integrating over the crystal faces). The parameters of the orthorhombic unit cell (space group Pccn) are a = 15.436(3), b = 20.198(5), c = 19.587(3) Å, Vcell = 6107(2) Å3, Z = 16, dcalc = 1.670 g/cm3. The two crystallographically independent copper atoms have a distorted octahedral environment (coordination node is CuN2O4), coordination number (CN) is 6 = 4 + t2. In the equatorial plane, two nitrogen atoms of ettz and two oxygen atoms of NO 3 ? groups are trans to each other; Cu-N = 1.983(8), C-ONO 3 ? = 1.978(7) Å (average). The nitrato groups fulfill chelate and bridging functions, complementing the coordination polyhedra of the copper atoms to distorted octahedra, where Cu-ONO 3 ? = 2.517(7) Å (average). The compound has a chain structure; the chains stretching along [001] are packed pairwise according to the hexagonal law.  相似文献   

11.
用密度泛函B3LYP/6-311+G**和高级电子相关的组态相互作用QCISD(T)/6-311+G**方法研究了OXO与X (2P3/2)双自由基反应的微观机理.研究结果表明该反应存在两个反应通道,产物分别为XO和X2+O2.由于形成产物XO的活化势垒较低,因而是主要反应通道,这与实验观察到的结果是一致的.而形成X2+O2的通道从动力学上看是不利的.  相似文献   

12.
A systematic investigation on the SN2 displacement reactions of nine carbene radical anions toward the substrate CH3Cl has been theoretically carried out using the popular density functional theory functional BHandHLYP level with different basis sets 6‐31+G (d, p)/relativistic effective core potential (RECP), 6‐311++G (d, p)/RECP, and aug‐cc‐pVTZ/RECP. The studied models are CX1X2?? + CH3Cl → X2X1CH3C? + Cl?, with CX1X2?? = CH2??, CHF??, CHCl??, CHBr??, CHI??, CF2??, CCl2??, CBr2??, and CI2??. The main results are proposed as follows: (a) Based on natural bond orbital (NBO), proton affinity (PA), and ionization energy (IE) analysis, reactant CH2?? should be a strongest base among the anion‐containing species (CX1X2??) and so more favorable nucleophile. (b) Regardless of frontside attacking pathway or backside one, the SN2 reaction starts at an identical precomplex whose formation with no barrier. (c) The back‐SN2 pathway is much more preferred than the front‐SN2 one in terms of the energy gaps [ΔE(front)?ΔE(back)], steric demand, NBO population analysis. Thus, the back‐SN2 reaction was discussed in detail. On the one hand, based on the energy barriers (ΔE and ΔE) analysis, we have strongly affirmed that the stabilization of back attacking transition states (b‐TSs) presents increase in the order: b‐TS‐CI2 < b‐TS‐CBr2 < b‐TS‐CCl2 < b‐TS‐CHI < b‐TS‐CHBr < b‐TS‐CHCl < b‐TS‐CF2 < b‐TS‐CHF < b‐TS‐CH2. On the other hand, depended on discussions of the correlations of ΔE with influence factors (PA, IE, bond order, and ΔE), we have explored how and to what extent they affect the reactions. Moreover, we have predicted that the less size of substitution (α‐atom) required for the gas‐phase reaction with α‐nucleophile is related to the α‐effect and estimated that the reaction with the stronger PA nucleophile, holding the lighter substituted atom, corresponds to the greater exothermicity given out from reactants to products. © 2012 Wiley Periodicals, Inc. J Comput Chem, 2012  相似文献   

13.
将CdS纳米粒子复合成TiO2纳米多孔膜上,用染料Ru(bpy)2(NCS)2对此复合半导体纳米膜电极进行每化,测量了不同CdS复合量的ITO/TiO2/CdS/Ru(bpy)2(NCS)2光阳极组成光电池的能量转换效率,实验证明,ITO/TiO2/CdS/Ru(bpy)2(NCS)2作为太阳电池光阳极的能量转换效率与TiO2/CdS复合半导体中CdS的含量有关,当CdS复合时间为5min的电池的短路电流为5.23A/m^2,开路电压为0.716V,能量转换效率为0.77%。  相似文献   

14.
Compound [Ni(hmt)2(SCN)2(H2O)2][Ni(SCN)2(H2O)4](H2O)2 (hmt=hexamethylenetetramine) was pre-pared and structurally characterized by means of X-ray single crystal diffraction. The two neutral units [Ni(hmt)2(SCN)2(H2O)2] and [Ni(SCN)2(H2O)4] are joined together through hydrogen bonds N…H-O, O…H-O and S…H-O. In the solid state, the compound has three-dimensional network structure. The determination of its variable-temperature magnetic susceptibilities (5~300K) shows that the magnetic behavior obeys the Curie-Weiss law over the whole temperature ranges.  相似文献   

15.
The novel catena-poly-μ-orotatobis(butylamine)copper(II), [Cu(μ-HOr)(ba)2]n (1), and diaqua(orotato)copper(II), [Cu2(HOr)2(H2O)4] (2), complexes have been prepared and characterized by elemental analysis, magnetic measurements, FT-IR spectroscopy, EPR spectroscopy, thermal analysis and X-ray diffraction. Both complexes crystallize in the monoclinic space group, C2/c in 1 and P21/n in 2. In the complexes, the copper(II) ion is chelated by a deprotonated pyrimidine nitrogen atom and a carboxylate oxygen atom of the orotate. While the coordination sphere around Cu(II) is completed by two N atoms from butylamine groups and a carboxylic O atom in the axial position from a neighboring molecule in 1, the square-planar environment of Cu(II) is completed by two water atoms and one axial position is occupied by the carbonyl oxygen atom from the symmetry related molecule in 2. The coordination sphere should be described as a square pyramid and (4+1)-geometry in 1 and 2, respectively. While complex 1 shows a polymeric arrangement, compound 2 has a dimeric arrangement. The non-covalent Cu(II)-π binding force is very important for stabilizing the crystal structure of 2. The thermal decomposition of the complexes has been predicted by the help of thermal analysis (TG, DTG and DTA).  相似文献   

16.
Alkylation of PdCl2(dotpm) (dotpm = bis(di-ortho-tolylphosphino)methane) with n-butyllithium produces the binuclear Pd(0) complex Pd2(μ-dotpm)2 and the elimination byproducts 1-butene, cis-2-butene, trans-2-butene, butane, and octane. The dibutyl complex, Pd(dotpm)(n-Bu)2, is presumed to be the reaction intermediate. The crystal structure of Pd2(μ-dotpm)2 reveals that the methylene groups of the bridging dotpm ligands are located on opposite sides of the Pd2P4 unit, forming an 8-membered ring that is in an elongated chair conformation. The four phosphorus atoms are not coplanar, and the P1-P2-P3-P4 ring has a torsion angle of 13.8°, which minimizes the spatial interactions among the o-tolyl rings. The Pd-Pd bond distance is 2.8560(6) Å, which indicates that there is a weak “closed-shell” bonding interaction between the d10-d10 metal centers. Each palladium atom has a nearly linear geometry, and the eight methyl groups of the dotpm ligands shield the open coordination sites on the metal centers. Four methyl groups shield the metal atoms above and below the Pd2P4 ring cavity, and four methyl groups block the open metal sites outside of the Pd2P4 ring. The Pd2(μ-dotpm)2 complex readily undergoes oxidative addition of dichloromethane to form the rigid A-frame complex Pd2Cl2(μ-CH2)(μ-dotpm)2.  相似文献   

17.
用密度泛函B3LYP/6-311+G**和高级电子相关的组态相互作用QCISD(T)/6-311+G**方法研究了OXO与X(2P3/2)双自由基反应的微观机理.研究结果表明:该反应存在两个反应通道,产物分别为XO和X2+O2.由于形成产物XO的活化势垒较低,因而是主要反应通道,这与实验观察到的结果是一致的.而形成X2+O2的通道从动力学上看是不利的.  相似文献   

18.
Two new Mo(V) and Mo(V)/Mo(VI) phosphates, β-Ba(MoO)2(P2O7)2 and Ba(MoO)2O(P2O7)PO4, with original tunnel structures have been synthesized. The first one crystallizes in the space group P21/n with , , , β=91.67°, and the second one in the space group Cc with , , , β=99.50°. β-Ba(MoO)2(P2O7)2 shows close relationships with the α-form, i.e., it consists of similar MoP2O11 units sharing their apices and forming [MoP2O10] chains. It differs from the latter by the configuration of the chains, so that one chain is linked to four other identical chains, instead of six chains in the α-form. Like the α-form, the β-form exhibits intersecting tunnels running along [010] and [011] direction where the Ba2+ cations sit. The 3D-framework of the second phosphate Ba(MoO)2O(P2O7)PO4, is built up of MoO6 octahedra, P2O7 groups, and PO4 tetrahedra, can be described by the assemblage of zig-zag [Mo2P2O14] chains through PO4 tetrahedra, forming large tunnels running along , occupied by Ba2+ cations. In this framework one observes that adjacent tunnels communicate through large six-sided windows, showing the opened character of this structure. The magnetic behaviour of these phosphates is discussed with respect to the results previously obtained by Canadell et al. [Chem. Mater. 9 (1997) 68].  相似文献   

19.
Rotationally resolved absorption spectra of I(2) (+) were recorded in 12 065-13 062 cm(-1) region by employing optical heterodyne velocity modulation absorption spectroscopy. In total, 4054 lines were assigned to 24 bands in the A(2)Π(3∕2,u)-X(2)Π(3∕2,g) system spanning the vibrational levels υ(') = 1-4 and υ(n) (') = 11-19. The assigned lines were globally fitted and an error of 0.003 cm(-1) was obtained. Rotational constants, B(υ), were used to derive equilibrium parameters B(e) (') = 0.03977725(77) cm(-1), a(e) (') = 1.1819(24)×10(-4) cm(-1), r(e) (') = 2.584386(25) A? of the X(2)Π(3∕2,g) state, and B(e) (') = 0.0305787(37) cm(-1), a(e) (') = 1.2353(23)×10(-4) cm(-1), r(e) (') = 2.94758(18) A? of the A(2)Π(3∕2,u) state. Vibrational energies were used to derive ω(e) (') = 239.0397(55) cm(-1), ω(e)x(e) (') = 0.64951(87) cm(-1) of the X(2)Π(3∕2,g) state and ω(e) (') = 138.103(11) cm(-1), ω(e)x(e) (') = 0.45027(34) cm(-1) of the A(2)Π(3∕2,u) state. The A(2)Π(3∕2,u) (υ(n) = 13) state was found to be rotationally perturbed by the a(4)Σ(1/2,u) (-) (υ(n) = 17) state through second-order spin-orbit coupling.  相似文献   

20.
丁二酸、戊二酸和己二酸分别与μ-氧-双[三(2-甲基-2-苯基)丙基]锡反应, 合成了3个二[三(2-甲基-2-苯基)丙基锡]二元酸酯(CH2)n[CO2Sn(CH2CMe2Ph)3]2(n=2 (1), 3 (2), 4 (3))。对化合物1~3进行了元素分析、红外光谱及核磁共振(1H, 13C)表征, 并通过X-射线晶体衍射分析测定晶体结构。化合物中锡与配基原子构成畸型四面体构型。试验表明, 化合物23均对人癌细胞Colo205、HepG2、MCF-7、Hela、NCI-H460的增殖具有较强的抑制作用。  相似文献   

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