Ag4超原子在超原子分子中的SP3杂化特性

为了研究和原子类似的超原子也能用来组建分子和材料的这一特性,以正四面体的Ag₄团簇为例构建了一系列的超原子分子Ag₄X₄(X=H,Li,Na,K,Cu,Ag,Au以及F,Cl,Br)． 基于超级价键模型,可以将正四面体的Ag₄团簇视为4电子的超原子,通过比较Ag₄和C组成的代表分子Ag₄X₄(X=Au,Cl)和CX₄(X=H,Cl)的成键模式和分子轨道,可以发现Ag₄超原子与sp³杂化的C原子相似．能量计算显示超原子分子是稳定的,大能隙和高芳香性也进一步证实了它们的稳定性．     

DFT investigation on the structures and stabilities of exohedral derivatives for D<Subscript>3</Subscript> C<Subscript>32</Subscript> fullerene: C<Subscript>32</Subscript>X<Subscript>n</Subscript> (X = H and Cl)

A systematic investigation of D₃ C₃₂ fullerene and its derivatives C₃₂X_n (X = H and Cl) has been performed using B3LYP/6-31G(d) method based on the density functional theory. The geometry structures, reaction energies, relative stabilities, and electronic properties have been studied. By investigating the possible C₃₂X_n (X = H and Cl) molecules, C₃₂H₂ and C₃₂Cl₂ behave more thermodynamically accessible with respect to other derivatives. The frontier molecular orbitals and electronic density of states calculations of C₃₂X₂ system indicate that H and Cl passivation have less contribution to the electronic structures, but significantly improve the stability of D₃ C₃₂ fullerene. Finally, the ¹³C NMR chemical shifts of C₃₂H₂ and C₃₂Cl₂ have been simulated to provide helpful information for further experiment identification.     

Conformational equilibria in dihaloheptasilanes X2Si[SiMe(SiMe3)2]2 with X = F,Cl, Br,I: A Raman spectroscopic and quantum chemical DFT study

Equilibrium geometries, stabilities and vibrational wavenumbers for conformers of the dihaloheptasilanes X₂Si[SiMe(SiMe₃)₂]₂ with X = F, Cl, Br and I were calculated at the density functional B3LYP level employing 6‐311G(d) basis sets and SDD pseudopotentials for Br and I. Two spectroscopically distinct low‐energy conformers were located for all four heptasilanes with energy differences of 5.5, 4.7, 1.9 and 1.2 kJ mol⁻¹ for X = F, Cl, Br and I, respectively. Five more conformers were found for difluoroheptasilane and four for X = Cl, Br and I. They all have relative energies larger than 7.5 and up to 17 kJ mol⁻¹ and are negligibly populated at room temperature. Variable temperature solution Raman spectra (−70 to + 100 °C) in a wavenumber range typical for Si Si stretching vibrations (280‐350 cm⁻¹) confirm these results. For X = Br and I, no temperature effects at all could be observed as a very rapid inter‐conversion between the two low‐energy conformers, which is fast even on the time scale of Raman spectroscopy, occurs. For X = Cl, rapid inter‐conversion also occurs, and a third conformer could be detected at higher temperatures (50–100 °C). For X = F, intensity changes with temperature are consistent with the presence of two low‐energy conformers. Copyright © 2007 John Wiley & Sons, Ltd.     

The density functional study of the stabilities,bond characters,static linear polarisabilities,and aromaticities of the ’in-out’ isomerism Hn-60@CnH60（n=70,72,74）

This paper uses the density functional theory to analyse the stabilities,bond characters,static linear polarisabilities,and aromaticities of the ’in-out’ isomerism H n-60 @C n H 60 (n=70,72,74).The binding energies,C-H bond energies,and energy gaps explore that the ’in-out’ isometric perhydrogenation of C n (n=70,72,74) can remarkably improve the stabilities.The static linear polarisabilies of H n-60 @C n H 60 (n=70,72,74) are indeed relative to their shapes,while they show almost nonaromatic character.This study can suggest that the ’in-out’ isometric perhydrogenation of fullerenes could lead to the invention of entirely novel potential hydrogen storage nanomaterials.     

N.M.R. study of internal motion in hexahydrated acid fluorides of cobalt and nickel

A linear relationship between the viscosity B-coefficient of the Jones-Dole equation for aqueous solutions of certain alkali metal salts and the enthalpy of hydration of the gaseous monatomic constituent ions has been established. The assumption that a similar rectilinear law applies to ammonium halides appears justified and the enthalpies of solution of NH₄ ⁺(g)+X^-(g) have been estimated and used to obtain magnitudes for the lattice energies of NH₄X(c) [X=F, Cl, Br, I]. In conjunction with experimental thermochemical data, the latter yield consistent results for the proton affinity of ammonia ΔH ₁ ^?=860·5±2·0 kJ mol^-1 (298·15 K). The lattice energies of the salts are, (in kJ mol^-1) 834 (NH₄F), 708 (NH₄Cl), 682 (NH₄Br) and 637(NH₄I).     

The stability, frontier orbitals, bond character, and static linear polarizability of the fluorinated fullerene H20@C80F60

This paper uses the density functional theory under generalised gradient approximation to analyse the stability,frontier orbitals,bond character,and static linear polarizability of H20@C80F60,which has not been isolated,as well as those of the synthesised H 20 @C 80 H 60.The H20@C80F60 should be considerably stable by analysing its energy and aromaticity.The inside H and outside X will play different role in the chemical reaction involving H 20 @C 80 X 60(X=H and F).The covalence of C-H bond is in the order that the inside C-H bond of H20@C80F60 > the inside C-H bond of H 20 @C 80 H 60 > the outside C-H bond of H 20 @C 80 H 60,whereas the C-F bond of H20@C80F60 have both the covalent and ionic characters.The static linear polarizabilities of C 80 and H 20 @C 80 X 60(X=H and F) are all isotropic.     

The Vibrational Spectra of Complexes with Planar Monothiooxamides. IV. The Copper(II) and Copper(I) Complexes of Neutral Monothiooxamides

The new complexes CuX₂(LH₂), CuX₂ (SH₃) (X = Cl, Br), CuX(LH₂), CuX(SH₃) (X = Cl, Br, I), CuX(H₄MTO)₂ (X = Cl, Br), Cul(H₄MTO) and CuX(H₃MMTO)₂ (X = Cl, Br, I), where LH₂ = N.N′-dimethyl-monothiooxamide, SH₃ = N(s)-methylmonothiooxamide, H₄MTO = monothiooxamide and H₃MMTO = N_(o)-methylmonothiooxamide, have been prepared. The complexes were characterized by elemental analyses, conductivity measurements, magnetic moments and spectroscopic (UV/VIS, FT-IR, Laser-Raman) studies. The vibrational analysis of the complexes has been given using NH/ND, CH₃/CD₃ and ⁶³cu/⁶⁵cu isotopic substitutions. The neutral monothiooxamides behave as monodentate ligands in the Cu(I) complexes coordinating through their thioamide sulfur atom. The ligands LH2 and SH₃ act as bidentate chelating agents in the Cu(II) complexes with ligated atoms being the thioamide sulfur and the amide oxygen.     

Mössbauer spectroscopy evidence for reductive loss of bromine from C60Br24 in reactions of halogenated C60 with ferrocene

Reactions of ferrocene (C₅H₅)₂Fe with halogenated fullerenes C₆₀X _n for X=F, Cl, Br andn = 15–39) yield non-stoichiometric solids with intense singlet Mössbauer spectra characteristic of Cp₂Fe₊ (where Cp=C₅H₅). The material isolated from reaction of Cp₂Fe with C₆₀Br₂₄ exhibits two different iron environments and magnetic ordering temperatures of 14 K and between 4.6 and 1.32 K. These data are seen to be consistent with loss of bromine from the fullerene and formation of ferricenium tetrahaloferrate salts.     

The Vibrational Spectra of Complexes with Planar Monothiooxamides. III. The Palladium(II) Complexes of Neutral Monothiooxamides

The new complexes trans-[PdX₂(H₄MTO)2] (X = Cl, Br, I), trans-[PdX₂(H₃MMTO)2] (X = Cl, Br, I), trans-[PdX₂(SH₃)2] (X = Cl, Br), [Pd(H₄MTO)₄]CI₂ and [Pd(H₃MMTO)₄]CI₂, where H₄MTO = monothiooxamide, H₃MMTO = N(o)-methylmonothiooxamide and SH₃ = N(s)-methylmonothiooxamide, have been prepared. The complexes were characterized by elemental analyses, conductivity measurements, X-ray powder patterns, thermal methods and spectroscopic (UV/VIS, FT-IR, Laser-Raman) studies. The vibrational analysis of the complexes is given using NH/ND and CH₃/CD₃ isotopic substitutions. Monomeric square planar structures are assigned for the complexes in the solid state. The neutral monothiooxamides behave as monodentate ligands coordinating through their thioamide sulfur atom. The complex [Pd(SH2)2] was isolated during the thermal decomposition of trans-[PdCl₂(SH₃)₂].     

Photoelectron spectra of bis-cyclopentadienyl metal dihalides

He(I) and HE(II) photoelectron spectra are reported for (η-C₅H₅)₂MX₂ (M = Ti; X = F, Cl, Br, I: M = Zr, Hf; X = Cl, Br: M = Ta; X = Cl, Br) and (η-MeC₅H₄)₂MX₂ (M = Nb, X = Cl: M = Mo; X = Cl, Br, I). A substantial variation is found in the ordering of the halogen and cyclopentadienyl ionizations, the order being dependent on the metal as well as on the halogen. The compounds may be divided into three classes, namely, those in which the electrons in cyclopentadienyl e₁ orbitals ionize at a lower energy than those occupying halogen pπ orbitals, those in which halogen pπ electrons have lower ionization energy than cyclopentadienyl e₁ electrons and those in which the corresponding electrons arise from extensively delocalized molecular orbitals with significant contributions from both these categories of fragment orbital.     

Vibrational spectra of 2, 4, 6-halogen and aminohalogen derivatives of 1, 3, 5-triazine

The IR (infrared) absorption spectra of the derivatives of symmetrical triazine C₃N₃X₃, C₃N₃X₂NH₂, and C₃N₃X(NH₂)₂ (X = F, Cl, Br) have been obtained; in addition, RS (Raman scattering) has been obtained from C₃N₃F₃ and C₃N₃Cl₃. In the case of the trihalogen triazines, the vibrations are attributed to symmetry types and characterized as to their modes. The spectra of the aminohalogen derivatives are interpreted by analogy with the spectra of C₃N₃X₃ and C₃N₃(NH₂)₃. The characteristic vibrations of the ring, NH₂ group, and C-X bonds are identified.The authors are grateful to Kh. E. Sterin and A. V. Bobrov (Commission on Spectroscopy, AS USSR) for their assistance in obtaining and measuring the RS spectra.     

Ultraviolet photoelectron spectra of gas phase and condensed tin and lead dihalides (MX2 ; M = Sn,Pb; X = Cl,Br, I)

The photoelectron spectra and electronic structures of the methylene dihalides, CH₂X₂ (X = F, Cl, Br and I), have been calculated by the overtapping-spheres SCF-Xα-MS method. The results are in good agreement with experimental data. Calculated assignments of the spectra are also presented and interpreted by assuming interaction between lone-pair and bonding orbitals.     

99Ru Mössbauer spectroscopic study on salts of ruthenocene with halogens

⁹⁹Ru Mössbauer spectra at 5 K have been measured on samples of salts of ruthenocene with halogens, expressed as [Ru(C₅H₅)₂X]Y (X=Cl, Br, Y=PF₆, and X=1, Y=13). The values of both the isomer shift and the quadrupole splitting of these salts with halogens are larger compared to those of ruthenocene. It is concluded that ruthenocene gives salts having direct chemical bonding between Ru and Cl, Br, or I, and that the Ru atom in each salt is in a higher oxidation state than 2+ in ruthenocene.     

Pressure- and photo-induced phase transition in mixed-valence gold complexes

The pressure- and photo-induced phase transition in mixed-valence gold complexes of Cs₂Au₂X₆ (X = Cl, Br, and I) has been investigated by means of the Raman scattering. The Raman-active Au-X stretching modes were deactivated by the pressure, which indicates a pressure-induced phase transition from the mixed-valence (MV) state to the single-valence (SV) state. The electronic phase diagrams of Cs₂Au₂X₆ (X = Cl and Br) as a function of pressure and temperature have been derived. A photoinduced phase transition from the MV state to the SV state has been found for Cs₂Au₂Br₆. The observed time behavior accompanying this phase transition is successfully interpreted by the Avrami model, indicating the three-dimensional character of the MV cluster growth.     

伽马CuX(X=Cl,Br,I)的电子结构和光学性质的第一性原理计算

基于第一性原理赝势平面波方法对伽马晶体CuCl, CuBr, CuI的体模量、体模量对压强的一阶偏导 数、电子结构、折射率等光学性质进行了计算.计算结果表明,广义梯度近似(GGA)下CuX(X = Cl, Br, I) 晶体的晶格常数与体模量的计算值与实验相差较小.与局域密度近似(LDA)相比, GGA更适合于 CuX(X = Cl, Br, I)晶体 的计算.这三者的价带都来源于Cu的3d态,导带部分主要来自Cu和卤素的s电子贡献,很少部分来自卤素的p电子 贡献.计算得到CuCl, CuBr, CuI的折射率分别为1.887, 2.015, 2.199,与应用Gladstone-Dale半经验关系得到 的结果符合得很好.     

The vapor phase Raman spectra,Raman band contour analyses,Coriolis constants,force constants,and values for thermodynamic functions of the trihalides of group V

The vapor phase Raman spectra have been recorded of the molecules PX₃ (X = F, Cl, or Br), AsX₃ (X = F, Cl, Br, or I), and SbX₃ (X = Cl, Br, or I) in sealed tubes at 22–365°C as appropriate. Attempts to record the vapor phase Raman spectra of the molecules PI₃, SbF₃, and BiX₃ (X = F, Cl, Br, or I) were unsuccessful. The infrared and Raman rotational branch separations of the a₁ species fundamentals for these molecules are in agreement with the theoretically calculated values. The Raman band contours of the e-species fundamentals have been analyzed to yield, in favorable cases, values for the corresponding Coriolis constants which have been compared with those obtained from infrared band contour analyses, and which have been employed to constrain the e-species force constants. It is concluded that the Raman contour method for defining Coriolis and thus force constants should be regarded as further, but not necessarily the best, experimental method with which to help to constrain the field. Values for various thermodynamic functions of the molecules have been calculated from the new values for the fundamental frequencies and from the most recent structural data.     

The effect of the hydrogen fluoride chain on the aromaticity of C6H6 in the C6H6···(HF)1–4 complexes

The effect of the hydrogen fluoride chain ((HF)_n) on the aromaticity and π character of C–C bonds of C₆H₆ in the C₆H₆···(HF)_n (n = 1–4) complexes were investigated using density functional theory employing RM05 functional. It was found that the binding energy between C₆H₆ and different (HF)_n chains showed a maximum at n = 3 (C₆H₆···(HF)₃). Also, the π–hydrogen interaction (πHI) and the bifurcated fluorine interaction (BFI) increased and decreased the π character of the C–C bond of C₆H₆, respectively. In addition, the change of aromaticity of the C₆H₆ due to the interaction with the HF chains was also studied using three different aspects such as aromatic fluctuation index (FLU), average two centre index (ATI) and proton nuclear magnetic resonance (HNMR) spectrum. The most change in the aromaticity happens when the C₆H₆ interacts with (HF)₃ chain. The variation of aromaticity with the binding energy and the summation of two-body terms were investigated and very good linear correlations were observed.     

Substituent effects on the 13C NMR chemical shifts of the imine carbon in N‐(4‐X–benzylidene)‐4‐(4‐Y–styryl) anilines

Long‐range electronic substituent effects were targeted using the substituent dependence of δ_C(C═N), and specific cross‐interactions were explored extendedly. A wide set of N‐(4‐X–benzylidene)‐4‐(4‐Y–styryl) anilines, p‐X–C₆H₄CH═NC₆H₄CH═CHC₆H₄–p‐Y (X = NMe₂, OMe, Me, H, Cl, F, CN, or NO₂; Y = NMe₂, OMe, Me, H, Cl, or CN) were prepared for this study, and their ¹³C NMR chemical shifts δ_C(C═N) of C═N bonds were measured. The results show that both the inductive and resonance effects of the substituents Y on the δ_C(C═N) of p‐X–C₆H₄CH═NC₆H₄CH═CHC₆H₄–p‐Y are less than those of the substituents Y in p‐X–C₆H₄CH═NC₆H₄–p‐Y. Moreover, the sensitivity of the electronic character of the C═N function to electron donation/electron withdrawal by the substituent X or Y attenuates as the length of the conjugated chain is elongated. It was confirmed that the substituent cross‐interaction is an important factor influencing δ_C(C═N), not only when both X and Y are varied but also when either X or Y is fixed. The long‐range transmission of the specific cross‐interaction effects on δ_C(C═N) decreases with increasing conjugated distance between X and Y. The results of this study suggest that there is a long‐range transmission of the substituent effects in p‐X–C₆H₄CH═NC₆H₄CH═CHC₆H₄–p‐Y. Copyright © 2012 John Wiley & Sons, Ltd.     

A hydrogen bonded complex C2H2…HBr isolated and characterized in the gas phase using pulsed-jet,Fourier transform microwave spectroscopy

A complex formed from ethyne and hydrogen bromide has been isolated and characterized by using a fast-mixing nozzle in conjunction with a pulsed-jet, Fourier transform microwave spectrometer. Any possible chemical reaction between the two components when mixed in the usual way was thereby precluded. The rotational constants A, B and C, the quartic centrifugal distortion constants δ_J, δ_Jk and δ_J and the Br nuclear hyperfine coupling constants X_aa and X_bb—X_cc (nuclear quadrupole) and M_bb (spin-rotation) were determined for each of the five isotopomers C₂H₂…H⁷⁹Br, C₂H₂…H⁸¹ Br, C₂H₂…D⁷⁹Br, C₂H₂…D⁸¹Br and C₂D₂…H⁷⁹Br. Interpretations of the spectroscopic constants show that the complex is planar and T shaped in the equilibrium conformation, with HCCH internuclear axis forming the cross of the T and the HBr internuclear axis lying along the C₂ axis of C₂H₂. The H of HBr is closer to the centre (?) of the π bond of ethyne, and therefore HBr is involved in a hydrogen bond to the π system, in which the distance of H from ? is r (?…H) = 2.469(1) A. The intermolecular stretching force constant is estimated as kσ = 5.38(2) Nm^?1 for the species involving a hydrogen bond (C₂H₂…H⁷⁹Br, C₂H₂…H⁸¹Br and C₂D₂…H⁷⁹Br) while this quantity increases to kσ = 5.68(2)Nm^?1 for those complexes bound through a deuterium bond (C₂H₂…D⁷⁹Br and C₂H₂…D⁷⁹Br). The opportunity is taken to consider similarities in the properties of complexes within the two series B…HBr and B…HC1 for a range of Lewis bases B, including B = C₂H₂. Some family relationships are identified in the two series.     

The universality of the electron spin relaxation in C60 mono radical anion salts: EPR studies of the model system [P(C6H5)4]2C60X

The C₆₀ radical anion salts [P(C₆H₅)₄]₂C₆₀X (X=Cl, Br, I) are grown via electrocrystallization and used as a model system to study the electron spin and nuclear spin dynamics as well as the molecular dynamics of C₆₀ mono anions in the solid state, which obey universal laws. It is shown that [P(C₆H₅)₄]₂C₆₀X is an exception among the fullerides, since the temperature dependence of the JT distortion, predicted for ionic C₆₀, can be deduced.