| Autor: |
Kaupp, M., Gress, T., Reviakine, R., Malkina, O. L., Malkin, V. G. |
| Zdroj: |
The Journal of Physical Chemistry - Part B; January 2003, Vol. 107 Issue: 1 p331-337, 7p |
| Abstrakt: |
The influence of ortho sulfur substitution in the modified tyrosyl radical in apo-galactose oxidase on the g tensor and the spin-density distribution has been studied by calculations on various model systems using an accurate DFT approach. Computed g tensors agree well with experimental observation, and they are intermediate between the extremely large substituent effect found in a previous DFT study and the very small changes found in MCSCF calculations. The origin of the substituent effects has been studied by fragment analyses of the spin−orbit/orbital-Zeeman g-tensor contributions, and it is discussed in relation to the spin-density distributions. The influence of hydrogen bonding on g tensors is studied by appropriate model complexes with water. Further calculations on radicals including heavier chalcogen substituents XH (X = O, S, Se, Te) predict very large gx and gy components with selenium- and tellurium-substituted systems due to large, direct substituent spin−orbit contributions. In view of an unexpectedly large gauge dependence of the g-tensor orientation in several cases, a recently developed implementation of gauge-including atomic orbitals (GIAO) has been applied. |
| Databáze: |
Supplemental Index |
| Externí odkaz: |
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