Abstract
Four manganese complexes of pentadentate ligands have been studied for their ability to act as oxygen evolution catalysts in the presence of Oxone or hydrogen peroxide. The complexes [Mn(PaPy3)(NO3)](ClO 4) (1) (PaPy3H = N,N-bis(2-pyridylmethyl)-amine-N-ethyl-2- pyridine-2-carboxamide) and [Mn(PaPy3)(μ-O)(PaPy 3)Mn](ClO4)2 (2) feature an anionic carboxamido ligand trans to the labile sixth coordination site, while [Mn(N4Py)OTf](OTf) (3) (N4Py = N,N-bis(2-pyridylmethyl)-N-bis(2-pyridyl)methylamine) and [Mn(PY5)(OH2)](ClO4)2 (4) (PY5 = 2,6-bis(bis(2-pyridyl)methoxymethane)-pyridine) have neutral ligands of varying flexibility. 1 and 2 are shown to evolve oxygen in the presence of either Oxone or hydrogen peroxide, but 3 evolves oxygen only in the presence of hydrogen peroxide. 4 is inactive. The activity of 1 and 2 with Oxone suggests that the presence of an anionic N-donor ligand plays a role in stabilizing putative high-valent intermediates. Anionic N-donor ligands may be viewed as alternatives to μ-oxo ligands that are prone to protonation in low-valent Mn species formed during a catalytic cycle, resulting in loss of catalyst structure.
| Original language | English |
|---|---|
| Pages (from-to) | 7615-7622 |
| Number of pages | 8 |
| Journal | Inorganic Chemistry |
| Volume | 52 |
| Issue number | 13 |
| DOIs | |
| Publication status | Published - Jul 1 2013 |
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ASJC Scopus subject areas
- Inorganic Chemistry
- Physical and Theoretical Chemistry
Cite this
An anionic N-donor ligand promotes manganese-catalyzed water oxidation. / Young, Karin J.; Takase, Michael K.; Brudvig, Gary W.
In: Inorganic Chemistry, Vol. 52, No. 13, 01.07.2013, p. 7615-7622.Research output: Contribution to journal › Article
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TY - JOUR
T1 - An anionic N-donor ligand promotes manganese-catalyzed water oxidation
AU - Young, Karin J.
AU - Takase, Michael K.
AU - Brudvig, Gary W
PY - 2013/7/1
Y1 - 2013/7/1
N2 - Four manganese complexes of pentadentate ligands have been studied for their ability to act as oxygen evolution catalysts in the presence of Oxone or hydrogen peroxide. The complexes [Mn(PaPy3)(NO3)](ClO 4) (1) (PaPy3H = N,N-bis(2-pyridylmethyl)-amine-N-ethyl-2- pyridine-2-carboxamide) and [Mn(PaPy3)(μ-O)(PaPy 3)Mn](ClO4)2 (2) feature an anionic carboxamido ligand trans to the labile sixth coordination site, while [Mn(N4Py)OTf](OTf) (3) (N4Py = N,N-bis(2-pyridylmethyl)-N-bis(2-pyridyl)methylamine) and [Mn(PY5)(OH2)](ClO4)2 (4) (PY5 = 2,6-bis(bis(2-pyridyl)methoxymethane)-pyridine) have neutral ligands of varying flexibility. 1 and 2 are shown to evolve oxygen in the presence of either Oxone or hydrogen peroxide, but 3 evolves oxygen only in the presence of hydrogen peroxide. 4 is inactive. The activity of 1 and 2 with Oxone suggests that the presence of an anionic N-donor ligand plays a role in stabilizing putative high-valent intermediates. Anionic N-donor ligands may be viewed as alternatives to μ-oxo ligands that are prone to protonation in low-valent Mn species formed during a catalytic cycle, resulting in loss of catalyst structure.
AB - Four manganese complexes of pentadentate ligands have been studied for their ability to act as oxygen evolution catalysts in the presence of Oxone or hydrogen peroxide. The complexes [Mn(PaPy3)(NO3)](ClO 4) (1) (PaPy3H = N,N-bis(2-pyridylmethyl)-amine-N-ethyl-2- pyridine-2-carboxamide) and [Mn(PaPy3)(μ-O)(PaPy 3)Mn](ClO4)2 (2) feature an anionic carboxamido ligand trans to the labile sixth coordination site, while [Mn(N4Py)OTf](OTf) (3) (N4Py = N,N-bis(2-pyridylmethyl)-N-bis(2-pyridyl)methylamine) and [Mn(PY5)(OH2)](ClO4)2 (4) (PY5 = 2,6-bis(bis(2-pyridyl)methoxymethane)-pyridine) have neutral ligands of varying flexibility. 1 and 2 are shown to evolve oxygen in the presence of either Oxone or hydrogen peroxide, but 3 evolves oxygen only in the presence of hydrogen peroxide. 4 is inactive. The activity of 1 and 2 with Oxone suggests that the presence of an anionic N-donor ligand plays a role in stabilizing putative high-valent intermediates. Anionic N-donor ligands may be viewed as alternatives to μ-oxo ligands that are prone to protonation in low-valent Mn species formed during a catalytic cycle, resulting in loss of catalyst structure.
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U2 - 10.1021/ic400691e
DO - 10.1021/ic400691e
M3 - Article
VL - 52
SP - 7615
EP - 7622
JO - Inorganic Chemistry
JF - Inorganic Chemistry
SN - 0020-1669
IS - 13
ER -