Structural Characterization of a Series of N5-Ligated MnIV-Oxo Species
(2020) In Chemistry - A European Journal 26(4). p.900-912- Abstract
Analysis of extended X-ray absorption fine structure (EXAFS) data for the MnIV-oxo complexes [MnIV(O)(DMMN4py)]2+, [MnIV(O)(2pyN2B)]2+, and [MnIV(O)(2pyN2Q)]2+ (DMMN4py=N,N-bis(4-methoxy-3,5-dimethyl-2-pyridylmethyl)-N-bis(2-pyridyl)methylamine; 2pyN2B=(N-bis(1-methyl-2-benzimidazolyl)methyl-N-(bis-2-pyridylmethyl)amine, and 2pyN2Q=N,N-bis(2-pyridyl)-N,N-bis(2-quinolylmethyl)methanamine) afforded Mn=O and Mn−N bond lengths. The Mn=O distances for [MnIV(O)(DMMN4py)]2+ and [MnIV(O)(2pyN2B)]2+ are 1.72 and 1.70 Å, respectively. In contrast, the Mn=O distance for... (More)
Analysis of extended X-ray absorption fine structure (EXAFS) data for the MnIV-oxo complexes [MnIV(O)(DMMN4py)]2+, [MnIV(O)(2pyN2B)]2+, and [MnIV(O)(2pyN2Q)]2+ (DMMN4py=N,N-bis(4-methoxy-3,5-dimethyl-2-pyridylmethyl)-N-bis(2-pyridyl)methylamine; 2pyN2B=(N-bis(1-methyl-2-benzimidazolyl)methyl-N-(bis-2-pyridylmethyl)amine, and 2pyN2Q=N,N-bis(2-pyridyl)-N,N-bis(2-quinolylmethyl)methanamine) afforded Mn=O and Mn−N bond lengths. The Mn=O distances for [MnIV(O)(DMMN4py)]2+ and [MnIV(O)(2pyN2B)]2+ are 1.72 and 1.70 Å, respectively. In contrast, the Mn=O distance for [MnIV(O)(2pyN2Q)]2+ was significantly longer (1.76 Å). We attribute this long distance to sample heterogeneity, which is reasonable given the reduced stability of [MnIV(O)(2pyN2Q)]2+. The Mn=O distances for [MnIV(O)(DMMN4py)]2+ and [MnIV(O)(2pyN2B)]2+ could only be well-reproduced using DFT-derived models that included strong hydrogen-bonds between second-sphere solvent 2,2,2-trifluoroethanol molecules and the oxo ligand. These results suggest an important role for the 2,2,2-trifluoroethanol solvent in stabilizing MnIV-oxo adducts. The DFT methods were extended to investigate the structure of the putative [MnIV(O)(N4py)]2+⋅(HOTf)2 adduct. These computations suggest that a MnIV-hydroxo species is most consistent with the available experimental data.
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- author
- Massie, Allyssa A. ; Denler, Melissa C. ; Singh, Reena LU ; Sinha, Arup LU ; Nordlander, Ebbe LU and Jackson, Timothy A.
- organization
- publishing date
- 2020-01-16
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- DFT calculations, electronic structure, oxido ligands, spectroscopy, X-ray absorption spectroscopy
- in
- Chemistry - A European Journal
- volume
- 26
- issue
- 4
- pages
- 13 pages
- publisher
- Wiley-Blackwell
- external identifiers
-
- pmid:31693757
- scopus:85076723841
- ISSN
- 0947-6539
- DOI
- 10.1002/chem.201904434
- language
- English
- LU publication?
- yes
- id
- 7ae4edb5-c845-43cc-9fb6-899419f763c5
- date added to LUP
- 2020-01-10 12:03:02
- date last changed
- 2024-03-20 02:31:12
@article{7ae4edb5-c845-43cc-9fb6-899419f763c5, abstract = {{<p>Analysis of extended X-ray absorption fine structure (EXAFS) data for the Mn<sup>IV</sup>-oxo complexes [Mn<sup>IV</sup>(O)(<sup>DMM</sup>N4py)]<sup>2+</sup>, [Mn<sup>IV</sup>(O)(2pyN2B)]<sup>2+</sup>, and [Mn<sup>IV</sup>(O)(2pyN2Q)]<sup>2+</sup> (<sup>DMM</sup>N4py=N,N-bis(4-methoxy-3,5-dimethyl-2-pyridylmethyl)-N-bis(2-pyridyl)methylamine; 2pyN2B=(N-bis(1-methyl-2-benzimidazolyl)methyl-N-(bis-2-pyridylmethyl)amine, and 2pyN2Q=N,N-bis(2-pyridyl)-N,N-bis(2-quinolylmethyl)methanamine) afforded Mn=O and Mn−N bond lengths. The Mn=O distances for [Mn<sup>IV</sup>(O)(<sup>DMM</sup>N4py)]<sup>2+</sup> and [Mn<sup>IV</sup>(O)(2pyN2B)]<sup>2+</sup> are 1.72 and 1.70 Å, respectively. In contrast, the Mn=O distance for [Mn<sup>IV</sup>(O)(2pyN2Q)]<sup>2+</sup> was significantly longer (1.76 Å). We attribute this long distance to sample heterogeneity, which is reasonable given the reduced stability of [Mn<sup>IV</sup>(O)(2pyN2Q)]<sup>2+</sup>. The Mn=O distances for [Mn<sup>IV</sup>(O)(<sup>DMM</sup>N4py)]<sup>2+</sup> and [Mn<sup>IV</sup>(O)(2pyN2B)]<sup>2+</sup> could only be well-reproduced using DFT-derived models that included strong hydrogen-bonds between second-sphere solvent 2,2,2-trifluoroethanol molecules and the oxo ligand. These results suggest an important role for the 2,2,2-trifluoroethanol solvent in stabilizing Mn<sup>IV</sup>-oxo adducts. The DFT methods were extended to investigate the structure of the putative [Mn<sup>IV</sup>(O)(N4py)]<sup>2+</sup>⋅(HOTf)<sub>2</sub> adduct. These computations suggest that a Mn<sup>IV</sup>-hydroxo species is most consistent with the available experimental data.</p>}}, author = {{Massie, Allyssa A. and Denler, Melissa C. and Singh, Reena and Sinha, Arup and Nordlander, Ebbe and Jackson, Timothy A.}}, issn = {{0947-6539}}, keywords = {{DFT calculations; electronic structure; oxido ligands; spectroscopy; X-ray absorption spectroscopy}}, language = {{eng}}, month = {{01}}, number = {{4}}, pages = {{900--912}}, publisher = {{Wiley-Blackwell}}, series = {{Chemistry - A European Journal}}, title = {{Structural Characterization of a Series of N5-Ligated Mn<sup>IV</sup>-Oxo Species}}, url = {{http://dx.doi.org/10.1002/chem.201904434}}, doi = {{10.1002/chem.201904434}}, volume = {{26}}, year = {{2020}}, }