Journal
INORGANIC CHEMISTRY
Volume 47, Issue 21, Pages 10090-10099Publisher
AMER CHEMICAL SOC
DOI: 10.1021/ic8013706
Keywords
-
Categories
Funding
- CNRS
- Ministre de I'Enseignement Superieur et de la Recherche
- Institut Charles Gerhardt Montpellier
- Sanofi-Aventis
- NSF [0614403]
- Division Of Chemistry
- Direct For Mathematical & Physical Scien [0614403] Funding Source: National Science Foundation
Ask authors/readers for more resources
Oxyl radical character in the Mn = O, group of the title system is shown from a density functional theory study to be essential for efficient C-H cleavage, which is a key step in C-H oxidation. Since oxyl species have elongated Mn-O bonds relative to the more usual oxo species of type Mn=O, the normal expectation would be that high trans-influence ligands X should facilitate oxyl character by elongating the Mn-O bond and thus enhance both oxyl character and reactivity. Contrary to this expectation, but in line with the experimental data (Jin, N.; Ibrahim, M.; Spiro, T. G.; Groves, J. T. J. Am. Chem. Soc. 2007, 129, 12416), we find that reactivity increases along the series X = O-2(-) < OH- < H2O for the following reasons. The ground-state singlet (S) is unreactive for all X, and only the higher-energy triplet (T) and quintet (Q) states have the oxyl character needed for reactivity, but the higher trans-influence X ligands are also shown to increase the S/T and S/Q gaps, thus making attainment of the needed T and Q states harder. The latter effect is dominant, and high trans-influence X ligands thus disfavor reaction. The higher reactivity in the presence of acid noted by Groves and co-workers is thus rationalized by the preference for having X = H2O over OH- or O-2(-).
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available