He (I) and He (II) photoelectron spectra of ozone

The he I (21.2 eV) and He II (40.8 eV) photoelectron spectra of ozone have been recorded under high resolution. Ionization potentials are identified at 12.75 eV, 13.02 eV, 13.57 eV, and two broad bands are centered at 17.7 eV and 20.1 eV. The experimental results and the orbital assignment are not completely in accord with those given recently in the literature.     

He(I) and He(II) photoelectron spectra of some mixed sandwich compounds of titanium,zirconium and hafnium

The He(I) and He(II) photoelectron spectra are reported for two series of transition metal mixed sandwich complexes of general formula L_aML_b (M = Ti, L_a = η⁵-C₅H₅, η⁵-CH₃C₅H₄, η⁵-C₅(CH₃)₅; M = Zr, Hf, L_a = η⁵-C₅(CH₃)₅; L_b = η⁷-C₇H₇ (series I); M = Ti, L_a = η⁵-CH₃C₅H₄, η⁵-C₅(CH₃)₅; M = Zr, L_a = η⁵-C₅(CH₃)₅; L_b = η⁸-C₈H₈ (series II)). Assignments were made of the metal d, cyclopentadienyl and carbocyclic π orbitals on the basis of He(I)/He(II) intensity ratios and shift effects and by comparison with UP data for related compounds. For series I no influence of the central metal upon the IEs of the highest occupied molecular orbital e₂ was observed. The IE of the non-bonding metal d_z2 orbital of Ti or Zr (5.28 and 4.70 eV, respectively) in the complexes of series II (L_a = η⁵-C₅(CH₃)₅) is very low.     

He I photoelectron spectra of some camphor derivatives

He I photoelectron spectra of several camphor derivatives have been measured and assigned.     

He I and Ne I photoelectron spectra of dichloro- and dibromomalononitrile

He I and Ne I photoelectron spectra are reported for the densely populated valence regions of gaseous malononitrile, H₂C(CN)₂, dichloromalononitrile, Cl₂C(CN)₂, and dibromomalononitrile, Br₂C(CN)₂. A minor reassessment of the H₂C(CN)₂ assignments is extended to permit plausible assignments for the previously unreported dihalodicyano species. Semiempirical calculations, HAM/3 and MNDO for H₂C(CN)₂, and MNDO for the X₂C(CN)₂ molecules, are shown to be of limited value for the location of strongly localised nitrogen orbitals.     

The surface activity of p-aminotriphenylmethane dyes in organic solvents - He(I) photoelectron spectra

At 0.23 M, the superficial layer of a solution of malachite green hydroxide or of brilliant green hydroxide in hydroxy-propionitrile consists entirely of the dye (as measured by He (I) photoelectron spectroscopy). This surface activity is weak or non-existent in the chloride and oxalate of malachite green, in some related dyes like brilliant green bisulphate and in the hydroxides and salts of both p-rosaniline and crystal violet.     

He(I) photoelectron studies of liquids and gases

He(I)photoelectron spectra of tetramethyl-p-phenylenediamine, phenol, benzyl alcohol and formamide in gaseous and liquid forms have been measured. The structure underlying these spectra is enhanced by plotting them in the form of their second derivatives. Comparison of the spectra of the gas phase and liquid surface reveals the effects of intermolecular interaction and sometimes enables the determination of the molecular form of the surface layer.     

He(I) photoelectron spectroscopy of halogen atoms

High concentrations of fluorine, chlorine and bromine atoms can be obtained in the ionization chamber of a photoelectron spectrometer if appropriate wall coatings are used in the sample inlet system. The potential of halogen atom-molecule reactions is demonstrated by the observation of the photoelectron spectrum of iodine atoms.     

Photoionization cross sections: He I and He II photoelectron spectra of saturated three-membered rings

The relative band intensities in the He I and He II photoelectron spectra of cyclopropane, oxirane, and thirane are interpreted by means of a recent theoretical approach. For each compound, the assignment of the two bands in the 15–18 eV range derived from our intensity arguments is opposite to the sequence of the respective ab initio eigenvalues.     

Measurement and calibration of the He(I) photoelectron spectra of gaseous and liquid ethanediol,propanediol and formamide

The He(I) photoelectron spectra of gaseous and liquid ethane-1,2-diol, propane-1,3-diol and formamide have been measured in a new instrument with a Bessel box analyser. Both phases were studied at ambient temperature or a little above with a resolution of 0.1 eV. A simple method of calibration is described. The addition of NaI to formamide (0.3 M) does not result in the appearance of the characteristic peaks of I^? in the spectrum but it causes the appearance of bands characteristic of water in the gas-phase spectrum.     

He I (584 Å) photoelectron spectra and photoionization cross sections of atomic chlorine and bromine

Well-resolved He I photoelectron spectra of atomic chlorine and bromine have been obtained without serious background electrons, giving rise to relative photoelectron intensities associated with differential photoionization cross sections at an angle of 90° with respect to the incident 584 Å radiation.     

He I photoelectron spectra and valence synchrotron photoionization for XC(O)SCl (X = F, Cl) compounds

Small penta-atomic molecules like FC(O)SCl and ClC(O)SCl have been analyzed by using both photoelectron spectroscopy (PES) and results derived from the use of synchrotron radiation in the same energy range. For this second experiment total ion yield (TIY), photoelectron photoion coincidence (PEPICO), and partial ion yield (PIY) spectra have been recorded. This set of data together with results obtained by computational chemistry allow us to study electronic properties and the ionization channels of both species. Thus, whereas the photodissociation behavior of FC(O)SCl can be divided into three well-defined energy regions, the fragmentation dynamics of ClC(O)SCl seems to be more complex. Nevertheless, simultaneous evaluation of the PES and valence synchrotron photoionization studies helps to clarify the molecular ionization processes.     

AM1 studies of photoelectron spectra

Five ionization potentials for thesp,ac andsp, sp conformers of (acetylthiomethyl)trifluorosilane MeC(O)SCH₂SiE₃ and six ionization potentials for the same conformers of (benzoylthiomethyl)trifluorosilane PhC(O)CH₂SiF₃ were calculated by the semiempirical AM1 method. The resulting values are in good agreement with the data of photoelectron spectroscopy only for thesp.ac conformers. The structure of the preferred conformer of (acetylthiomethyl)trifluorosilane was confirmed by measurement of its dipole moment in the gas phase. The influence of the long-range inductive effect (field effect) on the energy of nonbonding electrons of the carbonyl oxygen atom in the series of acetic acid derivatives was observed. For Part 9, see Ref. 1. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 236–241, February, 1998.     

AM1 study of photoelectron spectra

A correlation was found between the group dipole moments of substituents determined from the dipole moments of ethylene derivatives and the second ionization potentials of allene derivatives corresponding to the -MO of the C()-C() bond. It was shown that the concept of the effect of the substituent field cannot completely explain the observed phenomena, and the energies of the second ionic states of bromoallene and alkoxyallenes are lowered because of the interaction between nonbonded fragments through the systems of the compounds. It has been found that, in terms of orbital approximation, this interaction causes electronic destabilization of theanti-planar (trans) conformers of methoxyallene and methyl vinyl ether compared to theirsin-planar (cis) forms.For Part 5, see Ref. 1.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 48–54, January, 1995.     

AM1 studies of photoelectron spectra

Deep-lying π- and σ-orbitals of 10-alkylphenothiazines were studied by photoelectron spectroscopy and quantum-chemical AM1 calculations. It was demonstrated that in 10-ethylphenothiazine the lone electron pair of the S atom interacts with the π-system of the aromatic fragments. The π-MOs, whose energies are a function of the dihedral angle between the planes of the benzene rings of phenothiazines and are independent of the degree of pyramidality of the N atom, were found. The differences in the energy of these MOs were used for estimating equilibrium dihedral angles of tricyclic molecules in the gaseous phase. These values differ only slightly from those observed in the solid phase. The replacement of the hydrogen atom at position 10 by the methyl group leads to a decrease in the dihedral angle, leaving the orientation of the substituent unchanged. The orbital energies of phenothiazines, which were calculated by the AM1 method, adequately reflect the order of changes in the ionization potential. However, contributions of the two highest occupied π-MOs to the total charges on the N and S atoms are inconsistent with the experimental data. For Part 10, see Ref. 1. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1542–1548, August, 1998.     

X-ray photoelectron spectra of Rh(III) trifluoroacetate

A study was made of the x-ray photoelectron spectra of Rh(I) and Rh(III) trifluoroacetate complexes. It was shown by using the Cls bond energies of the carboxylate carbon atom as a basis that bridging and monodentate coordination of the trifluoroacetate group could be distinguished with high resolution.Institute of Chemical Physics, Russian Academy of Sciences, 142432 Chernogolovka. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 7, pp. 1549–1551, July, 1992.     

X-ray photoelectron spectra of ruthenium(II) phthalocyanines

Summary The Ru 3d_5/2 and 3p_3/2 x-ray photoelectron spectra of mono-and non-chlorinated ruthenium phthalocyanines were measured and the collected data on the core-level binding energies of ruthenium have been used to assess the oxidation state of the metal and the composition of the macrocyclic ligands.     

The He(I) photoelectron spectra of OsO4, and RuO4

The photoelectron spectra of ruthenium tetroxide and osmium tetroxide excited by He(I) radiation are reported. From their interpretation it follows that the first two strong low energy transitions in the electronic absorption spectra of OsO₄, RuO₄, TcO^?₄, ReO^?₄, MoO^2?₄ and WO^2?₄ can be assigned to t₁ → 2e and 3t₂ → 2e respectively.