Ab initiostudy of the Cu2pand3score-level XPS spectra of copper phthalocyanine

Abstract

The x-ray photoelectron spectra ͑XPS͒ of copper tetraazaporphyrin ͑CuTAP͒, used as a model of copper phthalocyanine͑CuPc͒ are studied by theoretical simulations. The nature of the main and satellite features observed in the XPS Cu 2p and Cu 3s photoelectron spectra are discussed based on the results of the charge-transfer ͑CT͒ model and of ab initio calculations in the sudden approximation limit. It is shown that the two descriptions of the core level final states can be derived from the two types of approaches. The final-state wave functions given by the CT model are described in a shakedown scenario. This process produces a ''well-screened'' final 2p 5 3d 10 L configuration (L denotes a ligand hole͒ on the Cu atom together with the core hole, resulting in the main spectral peak. On the other hand, the process where the outer electron stays on the ligand corresponds to the satellite with a poorly-screened 2p 5 3d 9 character. The ab initio calculations, performed on an isolated copper tetraazaporphyrin molecule at the Hartree-Fock ͑HF͒ level, the multiconfiguration self-consistent field level, and the hybrid density-functional-theory levels show that the core hole final states ͑satellite/main peak͒ can be attributed to valence-valence transitions. We show that a correct intensity distribution of the different features, including the so-called white line and the satellite structures, can be obtained when the electronic relaxation and correlation and the overlap between the ground-state and final-state Slater determinants are explicitly taken into account. It is found that the nature of the main peak is strongly depending on the Ligand-to-Metal charge transfer, on the exchange interaction and on the core-hole3d-hole interaction energies.

Catalytic oxidation of ascorbic acid via copper–polypyridyl complex immobilized on glass

“…1c), highlighting the expected presence of copper. 58,59 Finally, the I 3d XP spectrum of the 1-based monolayer in Fig. 1d was dominated by the 3d 5/2,3/2 doublet at 620.13 eV (I 3d 5/2 ) which can be assigned to ionic iodine, 60,61 in agreement with the expected composition of the monolayer (Fig.…”

Quaternary Germanide Arsenides ZrCuGeAs and HfCuGeAs

“…It has been well recognized that the BE shifts in Cu XPS spectra are unreliable for assigning Cu oxidation states 19. Instead, we make note of the line broadening in the Cu 2p 3/2 peak (FWHM of 1.1 eV, similar to 1.1–1.2 eV in Cu I halides but narrower than 3.0 eV in CuO)20–23 and the absence of a diagnostic satellite peak between the two main core‐lines as evidence for Cu 1+ (3d 10 configuration) 24,25. The As 3d spectrum reveals a broad envelope that was fitted to 3d 5/2 (41.2(1) eV) and 3d 3/2 peaks (41.9(1) eV) in an intensity ratio of 3:2 and FWHMs of 1.1 eV.…”

Synthesis, characterization and electrical properties of novel steric phthalocyanine polymers

“…The Cu 2p 2/3 peak of CuPPc can be split into two peaks by software simulation; the peak at 931.4 eV is assiged to Cu 2+ coordinating with CN groups or O atoms, 22 934.3 eV to Cu-N bond for CuPc. 23 It indicates that copper ions coordinate with end groups CN and bridge to oxygen atom in addition to the ordinary binding with N in phthalocyanine. The coordinative effect appears to be weaker than chemical binding since the peaks of CN-Cu and O-Cu shift to the direction of lower binding energy than Cu(CN) 2 and CuO (932.0-933.5 eV).…”