Skip to main content

Lund University Publications

LUND UNIVERSITY LIBRARIES

Enhanced Understanding of Structure-Function Relationships for Oxomanganese(IV) Complexes

Singh, Priya ; Lee, Yuri ; Mayfield, Jaycee R. ; Singh, Reena LU ; Denler, Melissa C. ; Jones, Shannon D. ; Day, Victor W. ; Nordlander, Ebbe LU and Jackson, Timothy A. (2023) In Inorganic Chemistry 62(45). p.18357-18374
Abstract

A series of manganese(II) and oxomanganese(IV) complexes supported by neutral, pentadentate ligands with varied equatorial ligand-field strength (N3pyQ, N2py2I, and N4pyMe2) were synthesized and then characterized using structural and spectroscopic methods. On the basis of electronic absorption spectroscopy, the [MnIV(O)(N4pyMe2)]2+ complex has the weakest equatorial ligand field among a set of similar MnIV-oxo species. In contrast, [MnIV(O)(N2py2I)]2+ shows the strongest equatorial ligand-field strength for this same series. We examined the influence of these changes in electronic structure on the reactivity of the oxomanganese(IV) complexes using hydrocarbons and thioanisole as substrates. The [MnIV(O)(N3pyQ)]2+ complex, which... (More)

A series of manganese(II) and oxomanganese(IV) complexes supported by neutral, pentadentate ligands with varied equatorial ligand-field strength (N3pyQ, N2py2I, and N4pyMe2) were synthesized and then characterized using structural and spectroscopic methods. On the basis of electronic absorption spectroscopy, the [MnIV(O)(N4pyMe2)]2+ complex has the weakest equatorial ligand field among a set of similar MnIV-oxo species. In contrast, [MnIV(O)(N2py2I)]2+ shows the strongest equatorial ligand-field strength for this same series. We examined the influence of these changes in electronic structure on the reactivity of the oxomanganese(IV) complexes using hydrocarbons and thioanisole as substrates. The [MnIV(O)(N3pyQ)]2+ complex, which contains one quinoline and three pyridine donors in the equatorial plane, ranks among the fastest MnIV-oxo complexes in C-H bond and thioanisole oxidation. While a weak equatorial ligand field has been associated with high reactivity, the [MnIV(O)(N4pyMe2)]2+ complex is only a modest oxidant. Buried volume plots suggest that steric factors dampen the reactivity of this complex. Trends in reactivity were examined using density functional theory (DFT)-computed bond dissociation free energies (BDFEs) of the MnIIIO-H and MnIV ≡ O bonds. We observe an excellent correlation between MnIV≡O BDFEs and rates of thioanisole oxidation, but more scatter is observed between hydrocarbon oxidation rates and the MnIIIO-H BDFEs.

(Less)
Please use this url to cite or link to this publication:
author
; ; ; ; ; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Inorganic Chemistry
volume
62
issue
45
pages
18357 - 18374
publisher
The American Chemical Society (ACS)
external identifiers
  • pmid:37314463
  • scopus:85163834233
ISSN
0020-1669
DOI
10.1021/acs.inorgchem.3c00600
language
English
LU publication?
yes
id
cf560361-f1da-431e-994d-4f15c6624501
date added to LUP
2023-10-10 13:29:19
date last changed
2024-04-19 02:11:33
@article{cf560361-f1da-431e-994d-4f15c6624501,
  abstract     = {{<p>A series of manganese(II) and oxomanganese(IV) complexes supported by neutral, pentadentate ligands with varied equatorial ligand-field strength (N3pyQ, N2py2I, and N4pyMe2) were synthesized and then characterized using structural and spectroscopic methods. On the basis of electronic absorption spectroscopy, the [MnIV(O)(N4pyMe2)]2+ complex has the weakest equatorial ligand field among a set of similar MnIV-oxo species. In contrast, [MnIV(O)(N2py2I)]2+ shows the strongest equatorial ligand-field strength for this same series. We examined the influence of these changes in electronic structure on the reactivity of the oxomanganese(IV) complexes using hydrocarbons and thioanisole as substrates. The [MnIV(O)(N3pyQ)]2+ complex, which contains one quinoline and three pyridine donors in the equatorial plane, ranks among the fastest MnIV-oxo complexes in C-H bond and thioanisole oxidation. While a weak equatorial ligand field has been associated with high reactivity, the [MnIV(O)(N4pyMe2)]2+ complex is only a modest oxidant. Buried volume plots suggest that steric factors dampen the reactivity of this complex. Trends in reactivity were examined using density functional theory (DFT)-computed bond dissociation free energies (BDFEs) of the MnIIIO-H and MnIV ≡ O bonds. We observe an excellent correlation between MnIV≡O BDFEs and rates of thioanisole oxidation, but more scatter is observed between hydrocarbon oxidation rates and the MnIIIO-H BDFEs.</p>}},
  author       = {{Singh, Priya and Lee, Yuri and Mayfield, Jaycee R. and Singh, Reena and Denler, Melissa C. and Jones, Shannon D. and Day, Victor W. and Nordlander, Ebbe and Jackson, Timothy A.}},
  issn         = {{0020-1669}},
  language     = {{eng}},
  number       = {{45}},
  pages        = {{18357--18374}},
  publisher    = {{The American Chemical Society (ACS)}},
  series       = {{Inorganic Chemistry}},
  title        = {{Enhanced Understanding of Structure-Function Relationships for Oxomanganese(IV) Complexes}},
  url          = {{http://dx.doi.org/10.1021/acs.inorgchem.3c00600}},
  doi          = {{10.1021/acs.inorgchem.3c00600}},
  volume       = {{62}},
  year         = {{2023}},
}