X-ray photoelectron spectra of heterometallic 3d-metal carboxylate complexes

The electronic structure and magnetic states in the heterometallic hexanuclear complex Mn 4 II Fe 2 III (μ4-O)2(Piv)10 • MeCN4 have been studied by X-ray photoelectron spectroscopy (XPS). The substitution of two Mn atoms for two Fe atoms in the hexanuclear complex was found to have an effect on the patterns of iron and manganese X-ray photoelectron spectra. XPS data are evidence of the high-spin paramagnetic state of MnII and FeIII atoms, as well as of the ligand-metal charge transfer upon complex formation. In the heteroatomic complex, the degree of bond covalence increased for both the manganese and iron atoms. The results obtained are in good agreement with X-ray diffraction data. © 2011 Pleiades Publishing, Ltd

Study of the electronic structure of polynuclear cobalt trimethylacetate complexes by Co3s and Co3p X-Ray photoelectron spectroscopy

The electronic structure of mono-, hexa-, and nonanuclear cobalt trimethylacetate complexes was studied by XPS. The Co3s- and Co3p X-ray photoelectron spectra of the complexes were recorded. The Co3p spectrum of bivalent cobalt was calculated in the isolated-ion intermediate-coupling approximation. Spectrum analysis showed that the [Co(N-Phobsqdi) 2(η'-N-Ph-opda)(OOCCMe3)] complex is a strong-field complex with Co(III) in the diamagnetic state; the [Co(dipy) 2(OOCCMe3)2], [Co(dipyam)(OOCCMe 3)2], and [Co9(μ3-OH) 6(μ-OOCCMe3)12(OCMe2) 4] are high-spin weak-field Co(II) complexes; and the [Co 6(μ4- O)2(OOCCMe3) 10(THF)4] complex contains both the Co(II) and Co(III) atoms. The energy position of major Co3s- and Co3p spectral maxima were found to be sensitive to the nature of the nearest environment of cobalt atoms. The data correlate well with X-ray crystallographic data. © Pleiades Publishing, Ltd., 2011

Study of the electronic structure of polynuclear cobalt trimethylacetate complexes by Co3s and Co3p X-Ray photoelectron spectroscopy

The electronic structure of mono-, hexa-, and nonanuclear cobalt trimethylacetate complexes was studied by XPS. The Co3s- and Co3p X-ray photoelectron spectra of the complexes were recorded. The Co3p spectrum of bivalent cobalt was calculated in the isolated-ion intermediate-coupling approximation. Spectrum analysis showed that the [Co(N-Phobsqdi) 2(η'-N-Ph-opda)(OOCCMe3)] complex is a strong-field complex with Co(III) in the diamagnetic state; the [Co(dipy) 2(OOCCMe3)2], [Co(dipyam)(OOCCMe 3)2], and [Co9(μ3-OH) 6(μ-OOCCMe3)12(OCMe2) 4] are high-spin weak-field Co(II) complexes; and the [Co 6(μ4- O)2(OOCCMe3) 10(THF)4] complex contains both the Co(II) and Co(III) atoms. The energy position of major Co3s- and Co3p spectral maxima were found to be sensitive to the nature of the nearest environment of cobalt atoms. The data correlate well with X-ray crystallographic data. © Pleiades Publishing, Ltd., 2011

X-ray photoelectron Fe3s and Fe3p spectra of polynuclear trimethylacetate iron complexes

X-ray photoelectron Fe3s and Fe3p spectra are employed to study the electron structure and the spin magnetic state of bi-, tri-, and hexa-nuclear trimethylacetate iron complexes. Assignment of the spectra is performed based on an isolated-ion Pauli-Fock calculation of Fe3s and Fe3p spectra of the Fe atoms in bi-and tri-valent states. Nonequivalent FeIII and FeII atoms are detected in tri-and hexa-nuclear complexes. Paramagnetic-limit molecular magnetic moments are calculated using effective atomic magnetic moments obtained from spin-sensitive spectral characteristics. Comparison of those values with the magnetic measurements data demonstrates antiferromagnetic interaction within the complexes. © 2010 Elsevier B.V. All rights reserved

X-ray photoelectron spectra of heterometallic 3d-metal carboxylate complexes

The electronic structure and magnetic states in the heterometallic hexanuclear complex Mn 4 II Fe 2 III (μ4-O)2(Piv)10 • MeCN4 have been studied by X-ray photoelectron spectroscopy (XPS). The substitution of two Mn atoms for two Fe atoms in the hexanuclear complex was found to have an effect on the patterns of iron and manganese X-ray photoelectron spectra. XPS data are evidence of the high-spin paramagnetic state of MnII and FeIII atoms, as well as of the ligand-metal charge transfer upon complex formation. In the heteroatomic complex, the degree of bond covalence increased for both the manganese and iron atoms. The results obtained are in good agreement with X-ray diffraction data. © 2011 Pleiades Publishing, Ltd

X-ray photoelectron Fe3s and Fe3p spectra of polynuclear trimethylacetate iron complexes

X-ray photoelectron Fe3s and Fe3p spectra are employed to study the electron structure and the spin magnetic state of bi-, tri-, and hexa-nuclear trimethylacetate iron complexes. Assignment of the spectra is performed based on an isolated-ion Pauli-Fock calculation of Fe3s and Fe3p spectra of the Fe atoms in bi-and tri-valent states. Nonequivalent FeIII and FeII atoms are detected in tri-and hexa-nuclear complexes. Paramagnetic-limit molecular magnetic moments are calculated using effective atomic magnetic moments obtained from spin-sensitive spectral characteristics. Comparison of those values with the magnetic measurements data demonstrates antiferromagnetic interaction within the complexes. © 2010 Elsevier B.V. All rights reserved

XPs study of the electronic structure of binuclear 3d transition metal pivalate complexes

Binuclear pivalate complexes of 3d transition metals (manganese, iron, cobalt, and nickel) with the same ligand environment and a lantern structure have been studied by X-ray photoelectron spectroscopy. The M2p, M3s, C1s, O1s, and N1s X-ray photoelectron spectra have been examined. A redistribution of elec- tron density in the OCO group has been revealed. It has been shown that the theory fits the experimental data on the energy separation between the high- and low-spin components in the M3s spectra and between the spin doublet components in the M2p spectra. It has been demonstrated that the iron, cobalt, and nickel com- plexes are paramagnetic at room temperature, whereas the manganese complex exhibits antiferromagnetic properties. There is a correlation between the size of the 3d subshell of the transition metal atom and the M- O and M-N bond lengths. © Pleiades Publishing, Ltd., 2012

XPs study of the electronic structure of binuclear 3d transition metal pivalate complexes

Binuclear pivalate complexes of 3d transition metals (manganese, iron, cobalt, and nickel) with the same ligand environment and a lantern structure have been studied by X-ray photoelectron spectroscopy. The M2p, M3s, C1s, O1s, and N1s X-ray photoelectron spectra have been examined. A redistribution of elec- tron density in the OCO group has been revealed. It has been shown that the theory fits the experimental data on the energy separation between the high- and low-spin components in the M3s spectra and between the spin doublet components in the M2p spectra. It has been demonstrated that the iron, cobalt, and nickel com- plexes are paramagnetic at room temperature, whereas the manganese complex exhibits antiferromagnetic properties. There is a correlation between the size of the 3d subshell of the transition metal atom and the M- O and M-N bond lengths. © Pleiades Publishing, Ltd., 2012