Theoretical studies of the magnetic couplings and the chemical indices of the biomimetic models of oxyhemocyanin and oxytyrosinase
Magnetic couplings and chemical indices of the Cu 2(μ–η 2:η 2–O 2) complexes have been investigated by DFT calculations. Distortion of the Cu 2O 2 core causes the reduction of orbital interactions between the d xy ± d xy orbitals of dicopper site and the σ∗ and π∗ orbitals of peroxide, weakening the...
Saved in:
Published in | Inorganica Chimica Acta Vol. 362; no. 12; pp. 4578 - 4584 |
---|---|
Main Authors | , , |
Format | Journal Article |
Language | English |
Published |
Elsevier B.V
15.09.2009
|
Subjects | |
Online Access | Get full text |
Cover
Loading…
Summary: | Magnetic couplings and chemical indices of the Cu
2(μ–η
2:η
2–O
2) complexes have been investigated by DFT calculations. Distortion of the Cu
2O
2 core causes the reduction of orbital interactions between the d
xy
±
d
xy
orbitals of dicopper site and the σ∗ and π∗ orbitals of peroxide, weakening the magnetic couplings.
Magnetic interactions and the nature of the chemical bonds of the biomimetic Cu
2(μ–η
2:η
2–O
2) complexes of oxyhemocyanin and oxytyrosinase have been investigated with hybrid density functional theory. The Cu
2(μ–η
2:η
2–O
2) species has drawn attention in type III copper proteins because this structure is suggested as an important motif in biological systems. Many synthetic modeling approaches have been performed and greatly developed our understanding of the character of the Cu
2(μ–η
2:η
2–O
2) species. Natural orbital analysis clearly shows that the superexchange interaction of the d
xy
orbitals of the Cu ions through the π
∗ orbitals of μ–η
2:η
2 peroxide is responsible for the antiferromagnetic couplings of these Cu
2O
2 system and that the distortion of the Cu
2O
2 core from a planar structure to a butterfly structure and elongation of the Cu–O bonds cause the reduction of orbital interactions between the d
xy
±
d
xy
orbitals of the dicopper site and the σ
∗ and π
∗ orbitals of peroxide, weakening the magnetic coupling between the Cu sites via μ–η
2:η
2-peroxide. |
---|---|
ISSN: | 0020-1693 1873-3255 |
DOI: | 10.1016/j.ica.2009.04.012 |