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1.
The reactions of the group 15 trihalides, MX(3) (M = As, Sb, Bi; X = Cl, Br), with the phosphine selenide SeP(p-FC(6)H(4))(3) result in the formation of co-crystals of formula MX(3)·SeP(p-FC(6)H(4))(3). No reaction was observed with MI(3) (M = As, Sb, Bi). The structures of MX(3)·SeP(p-FC(6)H(4))(3) (M = As, X = Br 2; M = Sb, X = Cl 3; M = Bi, X = Cl 5; M = Bi, X = Br 6) have been established, and are isomorphous, crystallising in the cubic I23 space group. All the structures feature a primary MX(3) unit, which has three weak secondary MSe interactions to SeP(p-FC(6)H(4))(3) molecules. However, each of these SeP(p-FC(6)H(4))(3) molecules bridges three MX(3) molecules, resulting in the generation of an M(4)Se(4) (M = As, Sb, Bi) distorted cuboid linked by the pnictogen-chalcogen interactions. Four opposing corners of the cuboid are occupied by the M atom (M = As, Sb, Bi) of an MX(3) pyramid, and the other four by the selenium atom of the phosphine selenide.  相似文献   

2.
We make the first application of semiclassical (SC) techniques to the plane-wavepacket formulation of time-domain (T-domain) scattering. The angular scattering of the state-to-state reaction, H + D(2)(v(i) = 0, j(i) = 0) → HD(v(f) = 3, j(f) = 0) + D, is analysed, where v and j are vibrational and rotational quantum numbers, respectively. It is proved that the forward-angle scattering in the T-domain, which arises from a delayed mechanism, is an example of a glory. The SC techniques used in the T-domain are: An integral transitional approximation, a semiclassical transitional approximation, a uniform semiclassical approximation (USA), a primitive semiclassical approximation and a classical semiclassical approximation. Nearside-farside (NF) scattering theory is also employed, both partial wave and SC, since a NF analysis provides valuable insights into oscillatory structures present in the full scattering pattern. In addition, we incorporate techniques into the SC theory called "one linear fit" and "two linear fits", which allow the derivative of the quantum deflection function, Θ?(')(J), to be estimated when Θ?J exhibits undulations as a function of J, the total angular momentum variable. The input to our SC analyses is numerical scattering (S) matrix data, calculated from accurate quantum collisional calculations for the Boothroyd-Keogh-Martin-Peterson potential energy surface No. 2, in the energy domain (E-domain), from which accurate S matrix elements in the T-domain are generated. In the E-domain, we introduce a new technique, called "T-to-E domain SC analysis." It half-Fourier transforms the E-domain accurate quantum scattering amplitude to the T-domain, where we carry out a SC analysis; this is followed by an inverse half-Fourier transform of the T-domain SC scattering amplitude back to the E-domain. We demonstrate that T-to-E USA differential cross sections (DCSs) agree well with exact quantum DCSs at forward angles, for energies where a direct USA analysis in the E-domain fails.  相似文献   

3.
Ag(PPh3)nX(n=1,2,3;X=Cl,Br,I)的电化学合成   总被引:3,自引:0,他引:3  
银配合物;;三苯基膦;电合成;Ag(PPh3)nX(n=1;2;3;X=Cl;Br;I)的电化学合成  相似文献   

4.
Following the alkane-elimination route, the reaction between tetravalent aryl tintrihydride Ar*SnH3 and trivalent rare-earth-metallocene alkyls [Cp*2Ln(CH{SiMe3}2)] gave complexes [Cp*2Ln(μ-H)2SnAr*] implementing a low-valent tin hydride (Ln=Y, Lu; Ar*=2,6-Trip2C6H3, Trip=2,4,6-triisopropylphenyl). The homologous complexes of germanium and lead, [Cp*2Ln(μ-H)2EAr*] (E = Ge, Pb), were accessed via addition of low-valent [(Ar*EH)2] to the rare-earth-metal hydrides [(Cp*2LnH)2]. The lead compounds [Cp*2Ln(μ-H)2PbAr*] exhibit H/D exchange in reactions with deuterated solvents or dihydrogen.  相似文献   

5.
The synthesis, IR spectra, and the temperatures of the transition into a ferromagnetic state (T c) of layered ferromagnetics [R3RX[MCr(C2O4)3 (M = Mn, Fe, Co, Cu, and Ni) with the [Ph3BuP]+, [Bu3RN]+ (R = Pr, Et, and Me) cations capable of subsequently changing the distances between metallooxalate layers have been considered. The temperatureT c has been found to be independent of the size of the organic cation. It is believed that the determining factors in the transition to a ferromagnetic state are exchange interactions inside the metallooxalate layer.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 2327–2330, September, 1996.  相似文献   

6.
The coupled cluster singles and doubles method with perturbative treatment of triple excitations is applied to calculate the potentials of M(z)-X complexes (M = Cu, Ag, and Au; X = He, Ne, and Ar; and z = ±1). The bond functions and the basis set superposition errors are considered to obtain accurate interaction energies. The potential energy curves of all complexes are obtained. The vibrational energy levels and the spectroscopic parameters for these complexes are determined. The analytical potential energy functions are also fitted based on the potential energies.  相似文献   

7.
Reactions of lanthanoid trichlorides with sodium cyclopentylcyclopentadienyl in THFafford bis(cyclopentylcyclopentadienyl) lanthanoid chloride complexes (C_5H_9C_5H_4)_2LnCl(THF)_n (Ln=Nd, Sm, n=1; Ln= Er, Yb, n= 0). The compound [CP'_2SmCl(THF)]_2 (2) (Cp' =cyclopentylcy-clopentadienyl) crystallizes from mixed solvent of hexane and THF in monoclinic space group P_2_1/cwith a = 11.583 (3), b = 23.019(6), c = 8.227 (2), β= 90.26 (2)°, V= 2194 (1)~3, D_c= 1.59 g/cm~3.μ= 28.6 cm~(-1), F(000) = 1060, Z= 2 (dimers). Its crystal molecule is a dimer with a crystallographicsymmetry center. The central metal atom Sm is coordinated to two Cp' rings, two bridging chlorineatoms and one THF forming a distorted trigonal bipyramid. The crystal of [Cp'_2ErCl]_2 (3) belongs tothe triclinic space group P with a = 11.264 (2), b= 13.296(5), c = 14.296(6), a = 96.99 (3), β=112.47(2), γ= 102.78(2)°, V= 1865(1)~3, D_c= 1.67 g /cm~3, μ= 48.0 cm~(-1), F(000) = 924, Z = 2 (dimers).The molecule is a dimer consisting of two Cp'_2 ErCl species bridged by two Cl atoms. The centralmetal atom Er is coordinated to two Cp' rings and two bridging chlorine atoms forming a pseudo-tetrahedron. All these complexes are soluble in THF, DME, Et_2O, toluene and hexane.  相似文献   

8.
采用密度泛函理论(DFT)的B3LYP方法, 在6-31G**和Lanl2dz水平上分别对(MN)nHm(M=Ga, In; n=1-4; m=1, 2)进行了优化和振动频率计算. 得到了上述团簇的最稳定构型、H原子的结合能以及它们的能隙. 结果表明, (MN)nH(M=Ga, In; n=1-4)的基态构型均为双重态, (MN)nH2(M=Ga, In; n=1-4)的基态构型均为单重态; 当氢的个数为1时, 加在N原子上比加在M(M=Ga, In)原子上稳定, 如有N3单元, 那么加在N3单元两侧的构型是相同的, 且它是最稳定的; 当氢的个数为2时, 除n=1外, 分别加在两个N原子上的构型是最稳定的, 如有N3单元, 那么分别加在N3单元分离最远的两个N原子的构型是最稳定的. GaNH、(GaN)3H 和InNH的结合能和能隙都很大, 说明这些团簇都有很高的稳定性.  相似文献   

9.
(XY)12(X=B,Al;Y=P)团簇的结构与稳定性   总被引:1,自引:0,他引:1  
张竹霞  武海顺 《化学学报》2005,63(1):60-64,F008
采用B3LYP/6031G*方法,对(XY)12(X=B,Al;Y=P)笼状团簇的同分异构体进行优化,筛选出能量最低的构型.讨论它们的几何构型、HOMO-LUMO能隙、生成焓、核独立化学位移(NICS)和自由能.得到(BP)12和(AlP)12团簇的最稳定构型均为具有Th对称性的四、六元环组成的笼,亚稳态结构中含有五元环。  相似文献   

10.
《Chemical physics》1987,118(3):437-444
Fluorescence decay profiles of NO excited levels slightly above the dissociation limit have been measured by a single-photon counting technique with nanosecond pulse excitation using an iodine flash lamp. Three iodine atomic lines in the vicinity of 180 nm are found to bring NO molecules into the levels A2Σ+(ν = 5, N = 9), B22Π32(ν = 8, J = 8.5), C2Π32(ν = 1, J = 8.5), D2Σ+(ν = 0, N = 5) and D2Σ+(ν = 1, N = 9). Extrapolated zero-pressure lifetimes for single rotational levels are obtained, except for the C state where only a lifetime of ⩽0.4 ns was obtained. Self-quenching rate constants are also determined under higher-pressure conditions. Helium was found to quench the NO A2Σ+(ν′ = 5) fluorescence very efficiently.  相似文献   

11.
The photo-induced decarbonylation of CpCr(NO)(CO)2 (1a) in MeCN solution in the presence of R2E2 (E = S, Se; R = Me, Ph) leads to the formation of chalcogenolato-bridged binuclear complexes Cp2Cr2(NO)2(-ER)2 [E = S; R = Me (2a), Ph (3a); E = Se, R = Me (4a), Ph (5a)] while reactions between CpM(NO)(CO)2 [M = Mo (1b), W (1c)] and Ph2E2 (E = S, Se) result in mononuclear complexes CpM(NO)(EPh)2 [M = Mo; E = S (9b), Se (10b); M = W, E = S (11c), Se (12c)]. The corresponding reactions of (1b) with Me2E2 (E = S, Se) yielded both mono and binuclear complexes: CpMo(NO)(SeMe)2 (8b), Cp2Mo2(NO)2(-EMe)2 [E = S (6b), Se (7b)]. The new complexes have been characterized by i.r., 1H-, 13C-n.m.r. spectra and by electron-impact mass spectrometry.  相似文献   

12.
用水杨酸和吡啶与Ni(ClO4)26H2O 合成了一个新颖配位聚合物[Ni(Hsal)2(Py)2]n。对配合物进行了X射线衍射结构表征, C24H20N2NiO6, Mr = 491.13, 晶体属三斜晶系, P 空间群, 晶胞参数: a = 7.372(2), b =10.852(2), c = 14.728(3) ? a = 108.36(3), b = 93.83(3), g = 103.67(3), V = 1073.7(4) ?。F(000) = 508, m = 0.949mm-1, Z = 2, Dc = 1.519 g/cm3。最后修正到R = 0.0390, wR = 0.0772。配合物中Ni为五配位, 呈四方锥构型。配合物中2个水杨酸根的配位方式不一样, 其中一个水杨酸根作为双齿桥连配体, 使配合物呈一维链状结构。水杨酸苯环的-堆积作用和分子间的氢键作用, 又使配合物呈二维网络结构。  相似文献   

13.
利用溶剂热法合成了2种新的有机杂化锑硒化合物[Ni(dap)3]2(Sb2Se5)].2H2O(1)和[Zn(dap)3]2(Sb2Se5)](2)(dap=1,2-丙二胺),单晶X射线衍射分析结果表明,1属于三方晶系,P3121空间群,晶胞参数为a=10.7574(14),b=10.7574(14),c=31.672(4),γ=120.00°,z=4。2属于单斜晶系,P21空间群,晶胞参数为a=10.772(2),b=16.391(3),c=11.704(2),β=100.912(4)°,z=4。在2种化合物中,Ni2 与Zn2 离子分别与3个dap配体螯合形成畸变八面体几何构型,其中dap配体的N原子是无序的,而二聚[Sb2Se5]2-阴离子是由2个SbSe3三角锥共用1个Se原子连接而成。  相似文献   

14.
黄小璇  许旋 《物理化学学报》2009,25(7):1362-1366
应用密度泛函理论(DFT)的PBE0方法, 金属原子采用SDD基组, H、C、O和N原子采用6-31G*基组, P和Cl原子采用6-311G*基组, 对单核配合物Ir(CO)Cl(Ph2Ppy)2(1), 双核配合物Ir(CO)(Cl)2(Ph2Ppy)2HgCl(2)、Ir(CO)Cl(Ph2Ppy)2HgCl2(3)和Ir(CO)(Cl)2(HgCl2)(Ph2Ppy)2HgCl(4)进行结构优化, 并在优化的基础上采用基组重叠误差(BSSE)校正计算相互作用能, 通过自然键轨道(NBO)和前线轨道分析研究Ir-Hg相互作用和氧化还原反应的实质. 通过计算发现, Ir(CO)Cl(Ph2Ppy)2与HgCl2发生氧化还原反应得到的产物2和4比非氧化还原产物3稳定. Ir-Hg相互作用强度顺序为3<4<2, 且随着Ir-Hg相互作用强度增大, HOMO轨道中Ir和Hg成分逐渐趋于接近. 配合物2和4都具有一对Ir-Hg成键与反键轨道, 其成键轨道的组成分别为0.5985sd0.06Hg+0.8012sd2.48Ir和0.5794sd0.05Hg+0.8151sd2.48Ir, 但3中Ir与Hg的相互作用较弱, 只存在弱相互作用(电荷转移作用), 表现为nIr→nHg的直接作用和σIr—P(1)→nHg、σIr—C(1)→nHg的间接作用.  相似文献   

15.
A neglected topic in the theory of reactive scattering is the use of parameterized scattering (S) matrix elements to calculate differential cross sections (DCSs). We construct four simple parameterizations, whose moduli are smooth step-functions and whose phases are quadratic functions of the total angular momentum quantum number. Application is made to forward glory scattering in the DCS of the H + D(2)(v(i) = 0, j(i) = 0) → HD(v(f) = 3, j(f) = 0) + D reaction at a translational energy of 1.81 eV, where v and j are vibrational and rotational quantum numbers respectively. The parameterized S matrix elements can reproduce the forward scattering for centre-of-mass reactive scattering angles up to 30° and can identify the total angular momenta (equivalently, impact parameters) that contribute to the glory. The theoretical techniques employed to analyze structure in the DCS include: nearside-farside theory, local angular momentum theory--in both cases incorporating resummations of the partial wave series representation of the scattering amplitude--and the uniform semiclassical theory of forward glory scattering. Our approach is an example of Heisenberg's S matrix programme, in which no potential energy surface is used. Our calculations for the DCS using the four parameterized S matrix elements are counterexamples to the following universal statements often found in the chemical physics literature: "every molecular scattering investigation needs detailed information about the interaction potential," and "an accurate potential energy surface is an essential element in carrying out simulations of a chemical reaction". Both these statements are false.  相似文献   

16.
刘文剑  黎乐民 《化学学报》1995,53(5):431-437
本文利用单电子非相对论Hartree-Fock-Slater和完全相对论Dirac-Fock-Slater两种离散变分局域密度泛函方法(DV-Xα), 对MX~4(M=Ti,Zr,Hf;X=Cl,Br)的电子基态和相应于低能UV光谱的激发态进行了计算, 结果与实验符合得较好。用Mulliken布居分析方法研究了分子的共价性质, 发现除HfBr~4外,相对论效应对金属与配体之间的键级影响很小。  相似文献   

17.
Three new tin coordination compounds (4,4'-Hbipy)2[Sn2(C2O4)3] ( 1 ), (4,4'-H2bipy)[Sn(C2O4)2] ( 2 ), and SnCl2(4,4'-bipy) ( 3 ) were synthesized under hydro-(solvo-)thermal conditions and their crystal structures were determined by single-crystal X-ray diffraction. Compound 1 exhibits a ionic structure based on discrete [4,4'-Hbipy]+ cations and [Sn2(C2O4)3]2– anions. These two units are linked via N–H ··· O hydrogen bonds to form a pseudo-one-dimensional zigzag hydrogen-bonded chain. In compound 2 , four-coordinate Sn atoms form monomeric tin dioxalato complexes, which are connected to the doubly protonated [4,4'-H2bipy]2+ cations through N–H ··· O hydrogen bonded to give a one-dimensional zigzag hydrogen-bonded chain. Compound 3 forms a three-dimensional hydrogen-bonded network, in which 1[SnCl2(4,4'-bipy)] linear chains are interconnected to each other by C–H ··· Cl hydrogen bonding. The solid-state UV/Vis/NIR diffuse reflectance spectroscopy shows that three compounds are broadband semiconductors. The thermogravimetric analysis evidences the thermal stability of the three compounds up to 175, 201, and 246 °C, respectively.  相似文献   

18.
蔡淑惠  李隽 《结构化学》1993,12(3):224-228
本文采用EHT近似下的紧束缚能带方法,计算了NbX(X=C,N,O)的能带结构。结果表明,它们的能带结构相近,Nb—X间存在较强的成键作用,传导电子主要具有Nb的4d特征,Nb—Nb键与超导电性相关,从C到N,Nb—Nb键共价性削弱,Tc提高。尽管计算所得NbO中Nb—Nb键强度介于NbC和NbN之间,但其实际Tc却比NbC和NbN的都低,这是NbO的空位效应所致,这一结果可从我们对有序缺陷的Nb_(0.75)O_(0.75)晶体能带结构的计算得到验证。  相似文献   

19.
Two new supramolecular compounds,2C 10 H 9 N 2 + ·C 8 HF 4 O 4 2-·C 8 H 2 F 4 O 4 /(H 2 tfbdc)· (tfbdc)·(Hbipy) 2 (1) and C 4 H 6 N 2 2+ ·C 8 HF 4 O 4 2-/(tfbdc)·(H 2 pz) (2),were synthesized and characterized by elemental analysis,IR spectra,and single-crystal X-ray diffraction.Compound 1 crystallizes in the triclinic system,space group P1,with a=8.3453(12),b=10.1798(15),c=10.6626(16),α=87.591(2),β=74.047(2),γ=69.006(2)°,V=834.53(12) 3,D c=1.614 g/cm 3,F(000)=400,u=1.45 cm-1,Z=2,the final R=0.0353 and wR=0.1005 for 5882 observed reflections with I > 2σ(I);and compound 2 crystallizes in the monoclinic system,space group P2 1 /c,with a=10.471(4),b=5.4419(19),c=12.249(4),β=114.909(6)°,V=633(4)3,D c=1.669 g/cm 3,F(000)=320,u=1.63 cm-1,Z=2,the final R=0.0794 and wR=0.2923 for 3213 observed reflections with I > 2σ(I).Both compounds 1 and 2 crystallize as charge-transfer organic salts with the dianionic or neutral acid components lying at the inversion centers.Hbipy + cations and anionic acid in compound 1 are linked to form a chain by means of C-H···O hydrogen bonds.Adjacent chains are further extended into a two-dimensional layer network via N-H···O and O-H···N hydrogen bonds.In compound 2,the acid and base subunits are arranged alternately to generate a linear tape motif via N-H O hydrogen bonds;these tapes are further combined into a three-dimensional array with CdSO 4 topology via C-H O intermolecular hydrogen bonds.  相似文献   

20.
采用密度泛函方法(B3LYP)优化了MX2(AsH3)2[M=Pd;X=Cl(1),Br(2),I(3)和M=Pt;X=Cl(4),Br(5),I(6)]的基态结构,得到的几何参数与实验结果符合.以基态几何为基础,将TD-DFT方法用于计算标题配合物的电子吸收光谱.研究结果表明,金属的dx2-y2与配体所组成的反键轨道为LUMO轨道,从而该类配合物具有d-d跃迁属性的吸收带;在多数跃迁过程中,配体也有较大的贡献.  相似文献   

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