ChemInform Abstract: OXIDATION OF PENTAAMMINECARBONYLOSMIUM(2+) TO μ‐DINITROGEN‐BIS(CIS‐TETRAAMMINECARBONYLOSMIUM)(4+)

BUHR, J. D.; Taube, Henry

doi:10.1002/chin.197945310

Cited by 1 publication

(3 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…5 Because only limited experimental EPR and NMR data for compounds 1-2 were available, we selected compound 3 for the methodological testing as it has the most complete set of data (Table 3) and the most challenging bonding situation. Solvent (Δ sol ) and spin−orbit (Δ SO ) corrections to the g-factor and ligand HF coupling constants (A) and their effects on the hyperfine 1 H and 13 C NMR shifts were analyzed using the DKS approach, and the results are summarized in Table 4.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

“…We will now investigate how these different bonding situations are reflected in the magnetic resonance parameters. "Long-Range" Fermi-Contact (FC) Contributions to Hyperfine 1 H and 13…”

Section: Calculation Of Epr and Nmr Parametersmentioning

confidence: 99%

“…[8][9][10] Other transformations involve complexes with chemisorbed nitrogen atoms 11 as intermediate species in the production of nitric oxide (NO) and in nitrogen-based fuel cells. 12 Nitrido complexes [13][14][15][16][17][18][19] have been specifically designed for oxidative N-N coupling reactions. Open-shell square-planar iridium amido complexes based on the PNP pincer and containing terminal −Cl, −N3, or ≡N ligands are particularly promising candidates (Figure 1), and have been prepared and structurally characterized by diffraction experiments, EPR, and 1 H NMR spectroscopy.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Electron-Spin Structure and Metal–Ligand Bonding in Open-Shell Systems from Relativistic EPR and NMR: A Case Study of Square-Planar Iridium Catalysts

Bora

Novotný

Ruud

et al. 2018

J. Chem. Theory Comput.

View full text Add to dashboard Cite

Electron and nuclear magnetic resonance spectroscopies are indispensable and powerful methods for investigating the molecular and electronic structures of open-shell systems. We demonstrate that the NMR and EPR parameters are extremely sensitive quantitative probes for the electronic spin density around heavy-metal atoms and the metal-ligand bonding. Using relativistic density-functional theory, we have analyzed the relation between the spin density and the EPR and NMR parameters in paramagnetic iridium(II/IV) complexes with a PNP pincer ligand. As the magnetic-response parameters for compounds containing 5d transition metal(s) are heavily affected by spin-orbit coupling, relativistic effects must be included in the calculations. We have used a recent implementation of the fully-relativistic Dirac-Kohn-Sham (DKS) method employing the hybrid PBE0 functional and an implicit solvent model to calculate EPR parameters and hyperfine NMR shifts. The modulation of the metal-ligand bond by the trans substituent (−Cl or ≡N) and the electronic spin structure around the central metal atom and ligands are shown to be reflected in the "long-range" through-bond Fermi-contact (FC) contributions to the ligand 13 C and 1 H hyperfine couplings. Interestingly, the hyperfine coupling constant of the ligand atom L () bonded directly to the iridium center changes its sign because of the dominating role of the paramagnetic spin-orbit (PSO) term. Furthermore, the electronic g-shift and the PSO contribution to the ligand are shown to invert their signs when nitrogen is substituted for chlorine, reflecting the different formal metal oxidation states and the change in metal-ligand bond character. A full understanding of the substituent effects is provided by using chemical bond concepts in combination with a molecular-orbital (MO) theory analysis of the second-order perturbation theory expression for the EPR parameters. Our findings are easily transferable to other systems containing d-block elements and beyond. Relativistic DFT calculations of magnetic-resonance parameters are expected to frequently assist in future experimental observations and the characterization of hitherto unknown unstable or exotic species.

show abstract

Section: ■ Results and Discussionmentioning

confidence: 99%

“…We will now investigate how these different bonding situations are reflected in the magnetic resonance parameters. "Long-Range" Fermi-Contact (FC) Contributions to Hyperfine 1 H and 13…”

Section: Calculation Of Epr and Nmr Parametersmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Electron-Spin Structure and Metal–Ligand Bonding in Open-Shell Systems from Relativistic EPR and NMR: A Case Study of Square-Planar Iridium Catalysts

Bora

Novotný

Ruud

et al. 2018

J. Chem. Theory Comput.

View full text Add to dashboard Cite

show abstract

ChemInform Abstract: OXIDATION OF PENTAAMMINECARBONYLOSMIUM(2+) TO μ‐DINITROGEN‐BIS(CIS‐TETRAAMMINECARBONYLOSMIUM)(4+)

Abstract: Die Oxidation von [Os(NH3)5(CO)](2+) durch Ce(IV) in saurer Lösung bei einem Molverhältnis der Reaktionspartner von 1.0 oder etwas weniger liefert beinahe quantitativ den zweikernigen μ‐Distickstoff‐Titelkomplex mit cis‐Struktur.

Cited by 1 publication

References 1 publication

Electron-Spin Structure and Metal–Ligand Bonding in Open-Shell Systems from Relativistic EPR and NMR: A Case Study of Square-Planar Iridium Catalysts

Electron-Spin Structure and Metal–Ligand Bonding in Open-Shell Systems from Relativistic EPR and NMR: A Case Study of Square-Planar Iridium Catalysts

Contact Info

Product

Resources

About