Electronic structure of platinum complex/Zn-porphyrinato assembled macrosystems, related precursors and model molecules, as probed by X-ray absorption spectroscopy (NEXAFS): theory and experiment

Polzonetti, Giovanni; Carravetta, Vincenzo; Iucci, Giovanna; Ferri, A.; Paolucci, G.; Goldoni, A.; Parent, P.; Laffon, C.; Russo, Maria Vittoria

doi:10.1016/j.chemphys.2003.09.036

Cited by 51 publications

(54 citation statements)

References 42 publications

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“…[8] At present NEXAFS C1s-and N1s-spectra of H 2 P and ZnTPP molecules are well known both experimentally and theoretically. [9][10][11] NEXAFS 1s-spectra obtained in present work well agree with these researches. The C1s-spectra fine structure elements of studied compounds consist of three groups: low peaks A 1 and A 2 (except molecules), high peaks B 1 and B 2 (except C 6 H 6 ) and wide bands C-E.…”

Section: Resultssupporting

confidence: 82%

“…The chemical shift of 2.25 eV between these atoms ensues of the protonated nitrogen. [11] The NEXAFS N1s-spectrum of ZnTPP consists of peak A (398.4 eV) and doublet band C-D assigned to the transitions to the π* states of the porphyrin macrocycle. In the pyridine spectrum the intensity peak B (398.6 eV), assigned to transitions to the π* state of the pyridine ring, dominates.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

NEXAFS Study of Zinc Porphyrins Intercalated into V2O5 Xerogel

Сивков¹,

Zabrodina²,

Некипелов³

et al. 2011

MHC

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Section: Resultssupporting

confidence: 82%

Section: Discussionmentioning

confidence: 99%

NEXAFS Study of Zinc Porphyrins Intercalated into V2O5 Xerogel

Сивков¹,

Zabrodina²,

Некипелов³

et al. 2011

MHC

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“…However, in the XPS of TSPP used as a reference sample, the only peak appeared with BE of 400.4 eV. Higher and lower energy peaks of TPP corresponded to protonated and nonprotonated nitrogen atoms (denoted as N1 and N2, respectively), as reported by Polzonetti et al 23 On the other hand, only the peak of TSPP corresponded to the higher peak of TPP, indicating that all of the nitrogen atoms in the porphine ring are N1. Hence, the higher and lower peaks of TCPP can be assigned to N1 and N2, respectively.…”

Section: Xpsmentioning

confidence: 79%

Local Structure of Nitrogen Atoms in a Porphine Ring of meso-Phenyl Substituted Porphyrin with an Electron-Withdrawing Group Using X-ray Photoelectron Spectroscopy and X-ray Absorption Spectroscopy

et al. 2005

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Metalloporphyrins with electron-withdrawing substitutes, such as carboxyl groups, at the meso-positions, and those immobilized on inorganic supports act as efficient and selective catalysts for the oxidation of hydrocarbons. [1][2][3][4][5][6][7] Porphyrin ligands with electron-withdrawing substitutes (PPEW) are currently of interest as precursors to stable metalloporphyrin catalysts for a variety of hydrocarbon-oxygenation reactions that are important for future energy development. [8][9][10][11][12][13][14][15][16][17][18][19] The effect of electronwithdrawing groups on the electron states of porphyrin macrocycles, especially of four nitrogen atoms in the porphine ring, is an important issue for studies in not only analytical chemistry, but also in coordination chemistry because it is related to the protonation of nitrogen atoms in the porphine ring and to the stability of metalloporphyrin complexes.Changes of the local structure and electronic states between four nitrogen atoms and protons in the porphine ring in the PPEW ligand have been elucidated using ab initio calculations 20 and ionization potentials. The results of local-density functional calculations and spectroscopic studies show that they are different from the meso and β positions of a variety of multiple substituents (alkyl-, aryl-, fluoro-, chloro-, bromo-, trifluoromethyl cyano-, nitro-, etc.) in the PPEW that were provided. 21 However, information regarding molecular orbitals (MOs), including the atomic orbitals of nitrogen in these literatures was not investigated. On the other hand, because the effect of electron-withdrawing groups strongly affects the energy level of the 1s orbital for nitrogen, it is necessary to reveal the electronic effect. Therefore, X-ray photoelectron spectroscopy (XPS) is a very suitable method because it is possible to observe the atomic orbital with a characteristic energy. In addition, the X-ray absorption near-edge structure (XANES) provides an effective verification of the local structure of an absorbing atom. So far, a correlation between the energy of the 1s orbital for N in a porphine ring and the electron-withdrawing strength of meso-substituents in the PPEW has been reported to be a result of XPS and ab initio calculations. 22 On the other hand, N K XANES measurements of porphyrins have been reported for the orientation and electronic structure of macromolecular arrays containing porphyrins, 23 porphyrin thin film, 24 porphyrins in petroleum asphaltenes, 25 and porphyrins with adsorbed nitrogen monoxide. 26 Nevertheless, few studies have used a combination of XPS and XANES, a correlation between the protonation to nitrogen atoms in a porphine ring, and the strength of electronwithdrawing groups in a meso-substituted porphyrin. To show correlations in this study, the spectra of N 1s XPS and N K XANES for tetrakis(p-carboxyphenyl)porphyrin (TCPP) were measured and analyzed from an electronic state calculation using the discrete variational (DV)-Xα MO method, 27 which is a first-principle calculation that is u...

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“…Considering first the spectra for a thick film of ZnPP, we can see that the molecule is deposited by UHV electrospray deposition in its entirety. The N 1s spectrum exhibits a single nitrogen chemical state, 29 2p spectrum shows the spin-orbit pair with the 2p 3/2 component appearing at 1022.4 eV, characteristic of the Zn 2+ oxidation state. 30 Almost identical spectra are obtained for the multilayer coverage, which again here corresponds to between 2 and 3 MLs.…”

Section: Resultsmentioning

confidence: 99%

X-ray absorption and photoemission spectroscopy of zinc protoporphyrin adsorbed on rutile TiO2(110) prepared by in situ electrospray deposition

Rienzo

Mayor

Magnano

et al. 2010

The Journal of Chemical Physics

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Zinc-protoporphyrin, adsorbed on the rutile TiO(2)(110) surface, has been studied using photoemission spectroscopy and near-edge absorption fine structure spectroscopy to deduce the nature of the molecule-surface bonding and the chemical environment of the central metal atom. To overcome the difficulties associated with sublimation of the porphyrin molecules, samples were prepared in situ using ultrahigh vacuum electrospray deposition, a technique which facilitates the deposition of nonvolatile and fragile molecules. Monolayers of Zn protoporphyrin are found to bond to the surface via the oxygen atoms of the deprotonated carboxyl groups. The molecules initially lie largely parallel to the surface, reorienting to an upright geometry as the coverage is increased up to a monolayer. For those molecules directly chemisorbed to the surface, the interaction is sufficiently strong to pull the central metal atom out of the molecule.

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Electronic structure of platinum complex/Zn-porphyrinato assembled macrosystems, related precursors and model molecules, as probed by X-ray absorption spectroscopy (NEXAFS): theory and experiment

Cited by 51 publications

References 42 publications

NEXAFS Study of Zinc Porphyrins Intercalated into V2O5 Xerogel

NEXAFS Study of Zinc Porphyrins Intercalated into V2O5 Xerogel

Local Structure of Nitrogen Atoms in a Porphine Ring of meso-Phenyl Substituted Porphyrin with an Electron-Withdrawing Group Using X-ray Photoelectron Spectroscopy and X-ray Absorption Spectroscopy

X-ray absorption and photoemission spectroscopy of zinc protoporphyrin adsorbed on rutile TiO2(110) prepared by in situ electrospray deposition

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