首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 11 毫秒
1.
The high resolution He 584 Å photoelectron spectra of fluorine substituted 1,2-diaza-, 1,3-diaza-, 1,4-diaza- and 2,3-diaza-naphthalene are presented. By means of fluorine substitution the analysis of the photoelectron spectra of the parent compounds can be made more definite. Unexpected shifts of the nitrogen “lone-pair” bands can be explained within the through-space and through-bond interaction model. From this explanation one can deduce that fluorine substitution can give experimental evidence about the symmetry character of the “lone-pair” molecular orbitals.  相似文献   

2.
A relationship is established between the average degree of polycondensation of butyl polytitanates and the intensity of the absorption band of the Ti-O-Ti grouping. The infrared spectra of acyl derivatives of alkyl orthotitanates are described for the first time; the data obtained indicate that the bond between the titanium and the acyl group is ionic in nature. The structure of previously synthesized derivatives of alkyl orthotitanates and dibasic acids is confirmed.  相似文献   

3.
4.
5.
6.
7.
8.
9.
The KαL1/KαL0 intensity ratio of fluorine is measured in five fluorine compounds with a crystal spectrometer. An anomalous reduction of this intensity ratio was observed in KF and SrF2, which is attributed to resonance electron transfer from the metal ion to the spectator vacancy in the fluorine ion. KαL2/KαL0 intensity ratio of fluorine is also measured. The measured relative intensities are compared with the theoretical estimates of Aberg. Formerly RSIC  相似文献   

10.
The frequencies and intensities in the IR spectra of silicon allyls are used to show that electronic interactions between widely separated atoms cause deviations from additivity in the parameters for the characteristic modes.  相似文献   

11.
The photoelectron spectra of a number of simple thiones including thiofenchone, thiocarbonates and thioamides have been recorded, and the bands corresponding to ionization energies in the range 7.5–13 eV have been interpreted using vibrational fine structure, comparison of He-I and He-II spectra, and CNDO/S calculations. In all compounds the non-bonded orbital mostly localized on the sulphur atom has the lowest ionization potential. The position of the bonding π and σ orbitals show a marked sensitivity to the nature of the substituents on the thiocarbonyl sulphur atom.  相似文献   

12.
Electron impact energy loss spectra at impact energies of 100 eV and 50 eV and a scattering angle of 2 degrees are presented for alkyl derivatives of H2O and related compounds. Spectra of H2O, CH3OH, CH3OCH3, ethylene oxide, CH3CH2OH, (CH3)2CHOH, (CH3)3C C2H5OC2H5 and tetrahydrofuran are tentatively assigned using derived term values and ionization potentials from photoelectron spectrosc Substituent effects on Rydberg orbital energies are discussed using Taft σ* values.  相似文献   

13.
The infra-red spectra of KH2PO4, NH4H2PO4, NaH2PO4, KH2AsO4, NH2H2AsO4, Ag2H3IO6 and (NH4)2H3IO6 and of their deuterated analogues have been recorded at room temperature and some of them also at low temperature in the ferroelectric phase. The interpretation of the particularly interesting spectral region between 3000 and 1500 cm?1, containing several OH bands, has been made in terms of the tunnelling of the protons between two minima of potential energy. These were taken to be of equal depth in the non-ferroelectric phase and unsymmetrical in the ferroelectric form. A quantum-mechanical treatment of the vibrational problem of the latter type has been carried out and is presented in the Appendix. Good agreement has been found between the theoretically predicted energy levels and the experimental data.  相似文献   

14.
The first197Au Mössbauer spectra for compounds in which gold is bound to boron clusters are reported, and their relation to the structure and bonding involved are discussed.
Au-197 Mössbauer spectra of some gold-boron cluster compounds
  相似文献   

15.
We analyzed TOF-SIMS spectra obtained from three different size of fullerenes (C60, C70 and C84) by using Ga+, Au+ and Au3+ primary ion beams and investigated the fragmentation patterns, the enhancement of secondary ion yields and the restraint of fragmentation by using cluster primary ion beams compared with monoatomic primary ion beams. In the TOS-SIMS spectra from C70 and C84, it was found that a fragment ion, identified as C60+ (m/z = 720), showed a relatively high intensity compared with that of other fragment ions related to C2 depletion. It was also found that the Au3+ bombardment caused intensity enhancement of intact molecules (C60+, C70+ and C84+) and restrained the fragmentation due to C2 depletion.  相似文献   

16.
17.
18.
The spectral distributions of external bremsstrahlung (EB) excited by beta particles from a 90Sr/90Y source in thick target compounds PbCl2, PbF2, Pb(NO3)2 and CdO were measured using a 3.8 cm × 3.8 cm NaI(Tl) crystal. The spectra, unfolded using the Liden-Starfelt procedure, showed fairly good agreement with theory (Tseng and Pratt) at low energies and some deviation (less than 15%) at higher energies. The discrepancy between theory and experiment increases with modified atomic number of the target compound and photon energy. The application of the measured/theoretical spectrum to estimate the bremsstrahlung dose is also discussed.  相似文献   

19.
He(Iα) excited photoelectron spectra, the inferred ionisation energies, and their assignment, are presented for perfluoro-benzene, -naphthalene, -anthracene, -phenanthrene, -pyrene and -acenaphthylene.  相似文献   

20.
The model consisting of the two-spin exchange interaction and the four-spin one is studied. The systematic change of the magnetic structures among MnS2, MnSe2 and MnTe2 is shown to be well-explained by this model. The three types of magnetic structures of EuSe is also discussed.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号