Photoelectron Spectroscopy of Bis(2,4-Pentanedione)−Oxovanadium(IV) [VO(acac)₂] and Derivatives:  Substituent Effects on the 2,4-Pentanedione Donor

Abstract

The electronic structure of derivatives of VO(acac)(2) is probed using gas-phase UV-photoelectron spectroscopy [acac = 2,4-pentanedione]. The effect on the metal center of electron-donating and -withdrawing groups on the acac ligands is examined. Ionizations from metal-based, acac-based, and V=O-based orbitals are clearly observed. We find that changes at the ligand periphery lead to equivalent changes in the energies of the metal-based and ligand-based ionizations. Additionally, we find that a linear correlation exists between the ionization energies of the metalated complexes and the pK(a) values of the free ligands, indicating that the pK(a) is a good indication of the overall electron-donating abilities of acac ligands.

Magnetic property and crystal structure of bis [N-(4-chlorophenyl) salicylideneaminato] oxovanadium (IV)

“…While the unpaired electron is essentially localized in the vanadium 3d xy orbital [45][46][47], the significant spin polarization of the other d orbitals is observed as a result of 3d atomic orbital spin population analysis ( Table 2). The isotropic spin polarization of 2p orbitals for axial oxygen atoms is also observed.…”

Application of DFT for the modeling of the valence region photoelectron spectra of boron and d‐element complexes and macromolecules

“…Experimental spectra, together with quantum chemical calculation results, have shown the role of back‐bonding into n ‐orbitals in covalent bonds; influence of the position of two heteroatoms (N and S) in metal–ligand interactions and other details of the electronic structure of the complexes. DFT calculations of transition metal β‐diketonate complexes for the interpretation of UP spectra have been performed elsewhere, but the orbital energies were used without correction for δ value for spectrum analysis, and the MO composition was discussed.…”

Valence electronic structure of sublimated Fe4single-molecule magnets: an experimental and theoretical characterization

“…Indeed, UPS is well known to be a powerful tool in probing the electronic structure of metallo-organic compounds. [16][17][18][19][20][21] For instance, the high volatility of many b-diketonato metal complexes has promoted exhaustive gas-phase UPS studies, which has allowed to investigate the dependence of the electronic structure on the central metal atom and ligand substituents. [19][20][21] UPS investigations of polynuclear systems, where several metal ions are held together by different ligands, are considerably more limited.…”

“…These clusters possess a propeller-like molecular structure, in which two tripodal ligands (L 3À ¼ Ph-C(CH 2 O) 3 3À ) connect the central iron ion to the three peripheral ones through double bridging alkoxide oxygen atoms. [16][17][18][19][20][21] For instance, the high volatility of many b-diketonato metal complexes has promoted exhaustive gas-phase UPS studies, which has allowed to investigate the dependence of the electronic structure on the central metal atom and ligand substituents. Within the Fe 4 family, these two clusters are the only ones that have been successfully sublimated in ultra-high vacuum (UHV) conditions, 13,15 preserving unaltered their magnetic properties.…”