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1.
The electronic structure of free radicals and Cu(II) complexes with the nitronyl nitroxide radical and aminonitrone is studied by X-ray photoelectron spectroscopy (XPS). N1s XPS spectra of nitrogen atoms of Cu(II) complexes with aminonitrones confirm the diamagnetic nature of the ligands. The binding energies of the main peak and the intense satellite structure in the Cu2p 3/2,1/2 spectra of the complexes under study correspond to the Cu(II) state. The structure of the satellite in the Cu2p 3/2,1/2 spectrum depends on the environment of the metal ion.  相似文献   

2.
Disubstituted iron phthalocyanine complexes were studied by X-ray photoelectron spectroscopy (XPS). Fe2p 3/2, N1s, and C1s XPS spectra were analyzed, and the role of the ligand in their generation was determined. Assignment of the magnetic properties of phthalocyanine iron complexes was done. Covalence of the metal-ligand bond was determined. The nature of the axial ligand in PctFe affects the electronic state of the central iron atom.  相似文献   

3.
The electronic structures of complexes of cobalt(II) halides with 2-(1H-pyrazol-1-yl)-4(3H)-pyrimidinone have been studied by X-ray photoelectron spectroscopy. The Co2p 3/2 lines of cobalt atoms, N1s lines of nitrogen atoms, and O1s lines of oxygen atoms in the X-ray photoelectron spectra have been analyzed. Based on these data for the free and coordinated ligands, the atoms of the ligand coordinated to the central metal atom are determined. The coordinated organic compound serves as an electron-donating ligand. The results obtained are consistent with IR and UV-Vis spectroscopic data.  相似文献   

4.
The electronic structure of cobalt complexes with bi-, tri-, and tetradentate ligands and the mutual influence of ligands in them have been studied by X-ray photoelectron spectroscopy. The Co2p, N1s, and O1s photoelectron spectra have been studied. Unlike low-spin Co(III) complexes, the high-spin Co(II) compound exhibits a strong satellite line in the Co2p spectrum. For the high-spin Co(II) compound having unpaired 3d electrons, the Co2p 1/2-Co2p 3/2 spin-orbit splitting is larger than that in the low-spin Co(III) complexes. All cobalt complexes under consideration contain strongly bound dioxygen, which can be considered an inherent structural unit.  相似文献   

5.
Bi-, tri-, and hexanuclear iron(II,III) trimethylacetate complexes were studied by X-ray photoelectron spectroscopy. The compounds differed in the number of Fe-O and Fe-N coordination bonds. The Fe 2p, Fe 3p, and N 1s X-ray photoelectron spectra were examined and the role of the ligand in their formation was elucidated. Based on the calculated multiplet splittings, numerous states were discerned in the Fe 2p spectra. This made it possible to reveal a correlation between the magnetic moment and some spectral parameters, such as the relative intensity and energy position of the satellites.  相似文献   

6.
Two Ni(II) adamantane complexes, [Ni(bqad)Cl2] (1) and [Ni(bpad)(dmbp)(H2O)](ClO4)2·CH3OH H2O (2) (bqad = N,N′-bis(2-quinolinylmethyl) amantadine, bpad = N,N′-bis(2-pyridylmethyl)amantadine, dmbp = 5,5′-dimethyl-2,2′-bipyridine) have been synthesized and characterized by elemental analysis, infrared spectroscopy and single crystal X-ray diffraction. The nickel centers in complex 1 have a distorted tetragonal pyramidal geometry, while the coordination polyhedron of 2 can be described as a distorted octahedron. The reaction kinetics for reduction of p-nitrophenol to p-aminophenol catalyzed by these complexes has been investigated by UV–visible spectrophotometry. Complex 1 exhibits a higher turnover frequency of 1.4 min?1 for the reduction of p-nitrophenol.  相似文献   

7.
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 sat3/2/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.  相似文献   

8.
The Mn3s X-ray photoelectron spectra of manganites were studied. It was shown that for the formal valence of manganese from 3+ to 3.3+, the doping holes are O2p in character; as the valence of manganese increases further, the Mn3d states acquire holes. For La0.7Sr0.3MnO3, the Mn3p-3d resonance spectra provided information about the occupied and unoccupied Mn3d states, and the correlation energy U = 6.7 eV was determined experimentally. An analysis of X-ray dichroism on the L absorption spectra of three-dimensional La7/8Sr1/8MnO3 showed that the cooperative Jahn Teller distortion of the orthorhombic phase at 240 K was related to (x 2 ? z 2)/(y 2 ? z 2) type orbital ordering.  相似文献   

9.
A Cu1O1.7 oxide film containing a large amout of superstoichiometric oxygen was obtained by low-temperature oxidation of metallic copper in the oxygen plasma. An STM study of the film structure showed that ~10 nm planar copper oxide nanocrystallites with particles packed parallel to the starting metal surface. In an XPS study, the spectral characteristics of the Cu2p and O1s lines indicated that particles with a CuO lattice formed (E bnd(Cu2p 3/2) = 933.3 eV and a shake-up satellite, E bnd(O1s) = 529.3 eV). The additional superstoichiometric oxygen is localized at the sites of contact of nanoparticles in the interunit space and is characterized by a state with the binding energy E bnd(O1s) = 531.2 eV. Due to the formation of a nanostructure in the films during low-temperature plasma oxidation, the resulting copper oxide has a much lower thermal stability than crystalline oxide CuO.  相似文献   

10.
Gas-phase electron diffractometry was used to study the molecular structure of N,N′-ethylenebis(salicylaldiminato)nickel(II), NiO2N2C16H14, [hereinafter Ni(salen)] at 583(5) K. The molecule has C 2 symmetry with a practically planar structure of the NiN2O2 coordination unit and with internuclear distances r α (Ni-O) = 1.882(21) Å and r α (Ni-N) = 1.889(22) Å. The results of B3LYP/CEP-31G molecular structure calculations are in good agreement with experimental data, whereas the RHF/CEP-31G method significantly overestimates the Ni-N internuclear distance and gives worse results for other structural parameters. According to 3LYP/CEP-31G calculations, the 1 A low-spin state is 28 kJ/mole lower in energy than the 3 B high-spin state.  相似文献   

11.
The influence of pressure on the high spin-low spin phase transition (HL transition) in a model Fe(phen)2(NCS)2 (polymorph II) compound at room temperature was studied by optical spectroscopy. An increase in pressure from atmospheric to 1.814 hPa caused the complete conversion of the low-spin to high-spin phase with the transition pressure p 1/2 ↑ = 0.567 hPa at the equilibrium concentration of the high- and low-spin phases. Pressure drop caused the reverse HL transition with p 1/2 ↓ = 0.543 hPa. The HL reversible transition took place with the transition pressure p 1/2 = 0.555 hPa and hysteresis with width Δp 1/2 = 0.024 hPa. The p 1/2 value for the pressure-induced HL transition corresponded to the T 1/2 value under pressure for the temperature-induced HL transition. The pressure dependences of the fraction of the high-spin phase determined from four independent measurements of the influence of pressure on the temperature-induced HL transition and the pressure-induced HL transition obtained in this work were compared. The experimental data were used to calculate the interaction and elastic energy parameters for temperature- and pressure-induced HL transitions. The qualitative coincidence of the interaction parameters for pressure- and temperature-induced HL transitions and the equality of the interaction parameter to elastic energy under pressure led us to conclude that the influence of pressure in two experiments well corresponds to the interaction energy and does not correspond the Gibbs potential.  相似文献   

12.
X-ray photoelectron and Mössbauer spectroscopy were used to study the composition and structure of 57Fe-Pd bimetallic black and 57Fe-Pd/SiO2 nanocomposites prepared by metal-vapor synthesis. The main parameters of the core level photoelectron spectra of 57Fe-Pd systems were determined. The bimetallic system was shown to be a disordered amorphous structure consisting of Pd particles, superparamagnetic γ-Fe2O3 nanoparticles with size 8–10 nm, and a Fe-O-Pd solid solution. Considerable broadening of Pd 3d peaks in 57Fe-Pd/SiO2 and an increase in the O 1s-Si 2p energy interval by 0.4 eV with respect to the spectrum of initial SiO2 were observed; this was evidence of the interaction of Pd with the support. The binding energy of Fe 2p 3/2 peak in the nanocomposite spectrum was close to that of Fe2O3, but had a smaller width of the satellite peak and a larger spin-orbit splitting, which was indicative of a considerable amount of FeOOH on the surface compared with the other iron oxides.  相似文献   

13.
The complexes of precursor with pentadentate Salten ligand has been shown to have high-spin state (S = 5/2) in a single crystal and polycrystalline phase and contain both high-spin and low-spin (S = 1/2) fractions in vitrified acetonitrile solutions. A correlation between ESR spectrum shape and crystallinity degree has been tracked for polycrystalline phase. The majority of complexes in crystals has been found to form exchange-coupled clusters. The ESR spectra of vitrified solutions have shown several types of high-spin centers and two kinds of low-spin complexes with different g-factors. On the basis of quantum chemical calculations, conclusion was drawn for the most likely structural form of the precursor in single crystal and polycrystalline samples and possible supramolecular associates in frozen solutions.  相似文献   

14.
The ligand 1,2-dimorpholinoethane (DME) was used to prepare Zn(II) and Ni(II) complexes of the general formulation MLX2 (L = DME, X = Cl or NO3). Zinc(II) complex exhibits spectral properties indicative of a distorted tetrahedral geometry, with DME coordinating through two nitrogen atoms and two chlorides completing the tetrahedron. This is in contrast to the six-coordinated, distorted octahedral geometry exhibited by nickel(II) complex of DME when NO3 was used as counter ions. The X-ray diffraction confirms the structures of two complexes and shows that the ligand coordinates through two nitrogen atoms while the two ether linkages are not involved in complexation, which would have been the case if the morpholine rings were in the boat form. The ligand and related complexes have antibacterial activity against the five Gram-positive bacteria: Bacillus subtilis ATCC 6633, Staphylococcus aureus ATCC 6538, Bacillus cereus NRRL-B-3711, Enterococcus faecalis ATCC 29212 and Streptococcus pyogenes and also against the three Gram-negative bacteria: Escherichia coli ATCC 11230, Pseudomonas aeruginosa ATCC 15442 and Klebsiella pneumonia ATCC 70063. The results showed that in some cases the antibacterial activity of the complexes exceeded the one of sulfisoxazole used as a standard.  相似文献   

15.
The nickel(II) complexes dichlorobis(1-tert-butylimidazole-2-thione)nickel(II) [Ni(tm t-Bu)2Cl2] (1), dinitratobis(1-tert-butylimidazole-2-thione)nickel(II) [Ni(tm t-Bu)2(NO3)2] (2), dichloro-bis(3-phenyl-5-methyl-pyrazole)(1-tert-butylimidazole-2-thione)nickel(II) [Ni(pzPh,MeH)2(tm t-Bu)Cl2] (3) and dinitratobis(3-phenyl-5-methyl-pyrazole)(1-tert-butylimidazole-2-thione)nickel(II) [Ni(pzPh,MeH)2(tm t-Bu)(NO3)2] (4) have been synthesized and studied. The single crystal X-ray diffraction analysis was carried out for 1 and 4 {Bruker Kappa Apex-II CCD diffractometer, MoK α radiation}. Crystal data for 1: monoclinic C2/c, a = 16.949(2) Å, b = 8.6647(10) Å, c = 15.461(3) Å, β = 117.662(4)°, V = 2011.1(5) Å3, Z = 4, D calc = 1.460 g/cm3. Crystal data for 4: triclinic P-1, a = 9.9775(7) Å, b = 11.2254(8) Å, c = 14.8068(10) Å, α = 75.401(4)°, β = 87.422(4)°, γ = 74.874(4)°, V = 1548.86(19) Å3, Z = 2, D calc = 1.405 g/cm3. Coordination core of complex 1 adopts distorted tetrahedral geometry whereas core 4 has distorted octahedral geometry. The bonded nitrates are of two types coordinating as monodentate and bidentate ligands.  相似文献   

16.
Two nickel(II) complexes [Ni(NIT-l′-MeBzlrn)2(Dca)2] (I, II) (NIT-l′-MeBzIm = 2-{2′-[(l′methyl)benzimidazolyl]}-4,4,5,5-tetramethylimidazoline-l-oxyl-3-oxide) have been prepared and structurally characterized by single-crystal X-ray diffraction. They are structural epimers. The complexe crystallizes in monoclinic, space group P21/n, Z = 4. Crystal data: C34H38N14NiO4, M r = 765.49, a = 15.019(3), b = 18.803(4), c = 15.756(3) Å, β = 109.399(3)°, γ = 90° (I); a = 13.934(3), b = 11.046(2), c = 24.570(5) Å, β = 90.024(2)° (II). The X-ray analysis reveals that Ni2+ ion resides in a distorted octahedral center. The complex was linked by intermolecular hydrogen bonds, resulting in a ID chain structure for I and a 2D network configuration for II.  相似文献   

17.
The Cu3p and Cu2p resonance photoelectron spectra of the valence bands and core levels as well as Ti and CuL 2,3 absorption spectra for monocrystals 1T-Cu x TiSe2 were studied. The valence spectra obtained at Cu3p and Cu2p resonance drastically differ from each other. For Cu 3p-3d resonance, there are several bands corresponding to different channels of excited state decay. Spectra of the valence bands at Cu 2p-3d resonance are virtually identical to the spectra of pure TiSe2. As follows from the absorption spectra, titanium atoms have the oxidation state 4+, whereas copper atoms are close to the free ion state.  相似文献   

18.
The reactions of the platinum and rhodium model catalysts applied to aluminum oxide with NOx (10 Torr NO + 10 Torr O2) were studied by X-ray photoelectron spectroscopy. The reaction conducted at room temperature formed on the surface of the oxide support the NO 3,s ? nitrate ions characterized by the N1s line at 407.4 eV and O1s line at 533.1 eV and the NO 2,s ? nitrite ions characterized by the N1s line with a binding energy of 404.7 eV. At the same time, the Pt4f and Rh3d lines of the supported platinum particles are shifted toward higher binding energies by 0.5–1.0 eV and 0.7–1.2 eV, respectively. It is assumed that the binding energies increase due to changes in the chemical state of the platinum metal in which oxygen is dissolved. The reaction of NOx with Pt/Al2O3 at 200°C forms platinum oxide defined by the Pt4f 7/2 line with a binding energy of 72.3 eV.  相似文献   

19.
A mononuclear coordination complex, quinidinum-zinc(II)-trichloride (I), and a multi-component ionic complex, quinidinum iron(III) tetrachloride hydrogen chloride hydrate (II), have been synthesized and characterized by elemental analyses, IR spectra, and single crystal X-ray diffraction (CIF files nos. 1497628 (I) and 1497629 (II)). The weak hydrogen-bonding interactions exist in both complexes I and II. Both complexes crystallize in the chiral space groups with the absolute configuration. Complex I crystallizes in the orthorhombic space group P212121 with a = 7.6651(6), b = 11.4923(9), c = 24.653(2) Å, and Z = 4. Complex II crystallizes in the monoclinic space group P21 with a = 6.6425(15), b = 18.660(4), c = 10.958(3) Å, β = 104.973(3), and Z = 2.  相似文献   

20.
Two new square planar complexes with the formula Co(L)2 · CH3OH (1) and Ni(L)2 · CH3OH (2) (HL = HN{C(Me)=NH}2 = N-acetimidoylacetamidine) have been synthesized by solvothermal reactions in methanol/acetonitrile. N-acetimidoylacetamidine ligand was derived from the self-condensation reaction of acetonitrile, and the reaction was promoted by the cooperation of M(II) (M = Co in 1 and M = Ni in 2) with diphenylcarbazide. 1 and 2 are characterized by single crystal X-ray diffraction, elemental analysis and infrared spectrum. Both complexes crystallize in the monoclinic space group P21/c with a = 9.329(6) Å, b = 11.494(7) Å, c = 13.040(8) Å, β = 92.945(11)°, V = 1396.3(16) Å3 and Z = 4 for 1, and a = 9.323(4)Å, b = 11.512(5) Å, c = 13.020(6)Å, β = 92.819(7)°, V = 1395.7(10)Å3 and Z = 4 for 2.  相似文献   

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