X-ray photoelectron spectra of polynuclear manganese complexes

Manganese trimethylacetate complexes with different ligand environments were studied by X-ray photoelectron spectroscopy (XPS). Changes in the Mn 2p, C 1s, O 1s, and N 1s X-ray photoelectron spectra caused by the substitution of Mn → N coordination bonds for Mn → O coordination bonds were examined. In the spectra of manganese trimethylacetate complexes, the satellite component was identified, which is evidence of the high-spin state of manganese atoms. An increase in the magnetic moment of the manganese complexes, both with the oxygen and mixed oxygen-nitrogen environment, is accompanied by an increase in the spin-orbit splitting, the difference in E _b between the satellite and the Mn 2p _3/2 line, and the ratio between the integrated intensities of the satellite and the Mn 2p _3/2 line (I sat_3/2/I Mn 2p _3/2). The XPS data made it possible to determine the measure of covalence of the metal-ligand bond. The XPS results are consistent with X-ray crystallography data.     

X-ray photoelectron spectra and structure of polynuclear nickel complexes

Mono- and binuclear nickel complexes of different stoichiometry have been studied by X-ray photoelectron spectroscopy (XPS). The Ni2p, Ni3p, and N1s X-ray photoelectron spectra have been examined, and the role of a ligand in their formation has been determined. As distinct from a low-spin Ni(II) complex, the Ni2p spectra of high-spin Ni(II) compounds show strong satellite lines. For high-spin Ni(II) complexes, which have unpaired 3d electrons, the Ni2p _1/2-Ni2p _3/2 spin-orbit splitting is larger than that for a low-spin Ni(II) compound. The presence or absence of the satellite structure has made it possible to classify these complexes with regard to their magnetic properties. The difference between the Ni2p _3/2 and N1s binding energies has made it possible to estimate the covalence of the metal-ligand bond. The XPS results are consistent with X-ray crystallography data.     

X-ray photoelectron spectroscopic investigation of conducting polymer blends

Electrochemically prepared films of conducting polymers of polypyrrole and polythiophene and their blends with polyamide have been investigated by X-ray photoelectron spectroscopy. In the N1s region of the spectra of films containing polypyrrole the peak corresponding to N(+) at 402.0 eV is separated from that of neutral N. The intensity of the N(+) peak can be correlated with the electrical conductivity of the films and the spectroscopically derived ratio of F/N(+) is close to 4 indicating that one BF(-)(4) dopant ion is incorporated for every oxidized nitrogen center. In the spectra of films of polythiophene and its blends peaks corresponding to S and S(+) can not be resolved but again the F/C ratio correlates with the electrical conductivity.     

X-ray photoelectron spectroscopic investigation of conducting polymer blends

Electrochemically prepared films of conducting polymers of polypyrrole and polythiophene and their blends with polyamide have been investigated by X-ray photoelectron spectroscopy. In the N1s region of the spectra of films containing polypyrrole the peak corresponding to N⁺ at 402.0 eV is separated from that of neutral N. The intensity of the N⁺ peak can be correlated with the electrical conductivity of the films and the spectroscopically derived ratio of F/N⁺ is close to 4 indicating that one BF^-₄ dopant ion is incorporated for every oxidized nitrogen center. In the spectra of films of polythiophene and its blends peaks corresponding to S and S⁺ can not be resolved but again the F/C ratio correlates with the electrical conductivity.     

X-ray photoelectron spectra of polyhydrido complexes of tungsten and molybdenum

X-Ray photoelectron spectroscopy has been applied to study MH₄L₄(M = or Mo, L = PHPh₂, PMePh₂, PEtPh₂, PBuPh₂, PEt₂Ph, P(OPr-i)₃ or $\text{1}\text{2}$ dppe). It has been shown that tungsten in these compounds has a negative charge whereas the charge of molybdenum is almost zero.     

X-ray photoelectron investigation of the surface of diamond and graphite

X-ray photoelectron spectroscopy was used to investigate the surface functional groups of natural diamond and graphite. An analysis of the spectra of the core shells made it possible to establish the presence of hydroxyl (ether), carbonyl, and carboxyl-like groups. It is shown that it is possible to identify acid oxyfunctional groups within the framework of a cluster approach.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 25, No. 4, pp. 490–495, July–August, 1989.     

X-ray photoelectron spectra of ylide—TCNQ charge-transfer complexes

Charge-transfer complexes of TCNQ with ylides, new-type donors, were synthesized and the X-ray photoelectron spectra of these complexes were measured. A broad satellite caused by TCNQ radicals observed.     

Theoretical and experimental X-ray photoelectron spectroscopy investigation of ion-implanted nafion

The membrane properties of a Nafion surface can be modified by ion implantation with N⁺ or F⁺. The results are presented of an X-ray photoelectron spectroscopy (XPS) study of implanted surfaces. For the interpretation of the XPS spectra, calculations using a semiempirical quantum chemical formalism (AM1) have been applied, in conjunction with a charge-potential model, to predict the C_1s core electron binding energies. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 551–556, 2004     

X-ray photoelectron spectroscopy of alkaline earth metal uranate complexes

Summary X-ray photoelectron spectra for MgUO_4–x, MgU₃O_8.9, CaUO_4–x, Ca₂UO₅, Ca₃UO₆, Ca₂U₃O₁₁, CaU₂O₇, CaU₄O₁₂, SrUO₄, SrUO_3.67, Sr₂U₃O₁₁, SrU₄O_12.8, Sr₂UO₅, Sr₃UO₆, BaUO₄, Ba₃UO₆, BaU₂O₇, Ba₂U₂O₇ and Ba₂U₃O₁₁ have been recorded.Recorded O(1s) peak positions range from 529.5 to 533.4 eV and certain trends can be related to data obtained from other studies. By contrast, the range of U(4f) peak positions is much smaller totalling 0.7 eV. All compounds show satellite structure to the high binding energy side of the U(4f) peaks. Satellites separated byca. 10 eV from the main peaks are assigned to a transition from the uranium-oxygen bonding band to the U(6d) conduction band.     

X-ray photoelectron spectra of metal complexes of substituted 2,4-pentanediones

The X-ray photoelectron spectra of 14 complexes of Al³⁺, Cr ³⁺, Fe³⁺, Co³⁺ and Cu²⁺ with 3-X-2,4-pentanedione (X = H, Cl, Br) were determined to analyse the nature of metal-ligand bonding in these complexes. The trend in the position of np photoelectron lines of X-group with a change of metal ion was decided by the relative contribution of metal-toligand and ligand-to-metal charge transfer. The analysis of the satellites in the M(2p_3/2) and M(2p_1/2) spectra suggested that the metal-ligand bond in the chromium(III) complex had higher covalent character than that in the iron(III) complex. The satellite separations in the O(1s) spectra of M(3-Xptdn)₃ were in the range 4.0-4.8 eV: these satellites were assigned to a shake-up transition of Lπ → Lπ^* character. The O(1s) spectra of Fe(3-Xptdn)₃ and A1(3-Xptdn)₃ displayed an additional strong peak to higher energy than that of the main peak (δE = 2.1–3.1 eV) when the samples of complexes were bombarded with argon ions for a longer time.     

Boron chelate complexes: X-ray and UV photoelectron spectra and electronic structure

Published data on the electronic structure of boron chelates are summarized for the first time. Ultraviolet photoelectron spectra of vapors, X-ray photoelectron spectra of molecular crystals, and results of modeling within the framework of the density functional theory are analyzed. Data on the effect of substituents on the electronic structure of complexes are systematized.     

X-ray photoelectron and quantum-chemical investigation of the electronic structure of palladium chloride

The results of an x-ray photoelectron investigation of the core levels and valence band of PdCl₂ have been presented. A theoretical interpretation has been formulated on the basis of calculations of the expanded Pd₆Cl₈ ⁴⁺ and Pd₆Cl₁₂ clusters by the X-scattered wave method and a band calculation of a one-dimensional [PdCl₂]_n crystal. The proposed scheme for the electronic structure of PdCl₂ satisfactorily accounts for the features of the x-ray photoelectron spectra, including the presence of satellite lines due to many-electron excitation. The inadequacy of the single-sphere approximation in the framework of the model of PdCl₄ ^2– for the theoretical interpretation of the electronic structure has been noted, and the significant role of the covalent component of the Pd-Cl bonds in the formation of palladium chloride has been demonstrated. The results of the XPS investigation in conjunction with the quantum-chemical calculations makes it possible to examine the optical spectra and the x-ray absorption and emission spectra of PdCl₂ on a single basis.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 22, No. 4, pp. 409–418, July–August, 1986.     

X-ray photoelectron spectra of tetraaza macrocyclic complexes of cobalt with molecular oxygen

X-ray photoelectron spectroscopy has been used to determine the electronic state of the cobalt-molecular-oxygen fragment, the type of coordination, and, in some cases, the nature of the bond between the central ion and the axial ligand in the complexes [Co^II(htd)(NCS))C10₄, [-O₂{Co(htd((X)}₂](ClO₄)₂ (X=NCS^–, N₃ ^–, NCO^–, OH^–), and [O₂{Co(htd)(Im)}₂](ClO₄)₄. It has been established that the NCO^– and NCS^– ligands are coordinated as electron donors in an axial position by means of their nitrogen atoms. A conclusion regarding the electronic structure of the Co^III-O₂ ^2–-Co^III fragment has been drawn on the basis of an analysis of the binding energy (E_b) of the Co 2p_3/2 electrons in the oxygenated complexes and in the corresponding low-spin cobalt(II) compounds and cobalt(III) compounds.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 26, No. 4, pp. 437–442, July–August, 1990.     

Fe3s X-ray photoelectron spectra of polynuclear iron complexes

Specific features of the electronic structure and spin magnetic state of iron atoms in bi-, tri-, and hexanuclear iron trimethylacetate complexes were studied by X-ray photoelectron spectroscopy. A correlation was found between the ionicity (of the spin state of iron atoms) and Fe3s binding energies, exchange splitting of the final photoionization state, and the energy position and intensity of charge-transfer satellites. Nonequivalent iron states were identified in tri- and hexanuclear complexes. The overall magnetic moment of the complexes was found to decrease with an increase of the individual magnetic moments of iron atoms, which is evidence of complicated mutual orientation of atomic magnetic moments in the complexes.     

X-ray photoelectron spectra of inorganic molecules XXlX. The characterization of mixed phosphido-phosphine and phosphido-phosphite complexes of transition metal carbonyl clusters using X-ray photoelectron spectroscopy

X-ray photoelectron spectroscopy has been found to provide a useful means of studying the electronic structure of the phosphorus atoms in PPh, PPh₂, PPh₃, PHPh and P(OMe)₃ ligands in a number of polynuclear cobalt and iron complexes.     

Spectroscopic investigation of uranium sorption on soil surface using X-ray photoelectron spectroscopy

A study was carried out to understand the sorption of uranium (U) onto soil surface and identify the species of U on soil surface using X-Ray Photoelectron Spectroscopy (XPS). For the study soil was amended with uranyl nitrate and surface speciation study was carried out by investigating the energy region for U in spectrum. Analysis of spectrum revealed that U is present in U(VI) state. Deconvolution of XPS spectrum of U(VI) sorbed on soil surface revealed that U(VI) species such as, UO₂ ²⁺ and (UO₂)_x(OH) _y ^(2x?y)+ form complex with silanol, aluminol and goethite sites. The possible surface complexation is: ≡Al(OH)₂UO₂ ²⁺, ≡SiO₂UO₂, ≡SiO₂(UO₂)₃(OH)₅ and ≡Fe(OH)₂UO₂.     

An X-ray photoelectron spectroscopic study of some copper(II) tetraaza complexes

A selected series of copper(II) tetraaza complexes, involving open-chain and macrocyclic ligands, has been studied by X-ray photoelectron spectroscopy. The binding energy data obtained are interpreted in terms of the structures of these complexes with particular reference to the existence of π-electron delocalisation over metal and ligand, peripheral ring substituents, cation-anion interaction and hydration water. It is apparent that the degree of cation-anion interaction and photoreduction is a function of the existing experimental conditions.     

X-ray photoelectron and X-ray emission study of the electronic structure of hexanuclear Mn(II,III) pivalate complexes

The electronic structure of hexanuclear Mn(II,III) pivalate complexes with tetrahydrofuran and isonicotinamide are studied by X-ray photoelectron spectroscopy and X-ray emission spectroscopy. It is shown that when isonicotinamide substitutes for tetrahydrofuran the spin state of manganese ions is retained; the electron density increases on the manganese and oxygen atoms of the [Mn₆(O)₂Piv₁₀] core.