Abstract
The synthesis and characterization of the title trisphenolate ligand are described. From its reaction with manganese(III) three complexes were isolated. The crystal structures revealed one pentacoordinate monomer and two similar dimers with different solvents of crystallization. In the dimers the metal ions are hexacoordinate and connected through bridging of two phenolates. A combination of electrochemistry and EPR spectroscopy showed that, in acetonitrile, the isolated batches were all identical and mainly monomeric, indicating that the mononuclear complex is in equilibrium with the dimer and perhaps also with complexes of higher nuclearity, as suggested by the detection of both the trimer and the tetramer by electrospray ionization mass spectrometry (ESI-MS). The successful use of the monomer batch as an epoxidation catalyst indicated that a high-valent manganese-oxo species can be formed, although it is probably short-lived. This is also suggested by EPR studies of the species formed by electrochemical oxidation of the complex. Upon one-electron oxidation, a manganese(IV) species was formed, which was at least partly converted to another species containing a phenoxy radical.
| Original language | English |
|---|---|
| Pages (from-to) | 3757-3768 |
| Number of pages | 12 |
| Journal | Chemistry - A European Journal |
| Volume | 8 |
| Issue number | 16 |
| DOIs | |
| Publication status | Published - Aug 16 2002 |
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Keywords
- EPR spectroscopy
- Manganese
- Redox chemistry
- Structure elucidation
ASJC Scopus subject areas
- Chemistry(all)
Cite this
Synthesis, redox properties, and EPR spectroscopy of manganese(III) complexes of the ligand N,N-bis(2-hydroxybenzyl)-N′-2-hydroxybenzylidene-1,2-diaminoethane : Formation of mononuclear, dinuclear, and even higher nuclearity complexes. / Schmitt, Heimo; Lomoth, Reiner; Magnuson, Ann; Park, Jonathan; Fryxelius, Jacob; Kritikos, Mikael; Mårtensson, Jerker; Hammarström, Leif; Sun, Licheng; Åkermark, Björn.
In: Chemistry - A European Journal, Vol. 8, No. 16, 16.08.2002, p. 3757-3768.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Synthesis, redox properties, and EPR spectroscopy of manganese(III) complexes of the ligand N,N-bis(2-hydroxybenzyl)-N′-2-hydroxybenzylidene-1,2-diaminoethane
T2 - Formation of mononuclear, dinuclear, and even higher nuclearity complexes
AU - Schmitt, Heimo
AU - Lomoth, Reiner
AU - Magnuson, Ann
AU - Park, Jonathan
AU - Fryxelius, Jacob
AU - Kritikos, Mikael
AU - Mårtensson, Jerker
AU - Hammarström, Leif
AU - Sun, Licheng
AU - Åkermark, Björn
PY - 2002/8/16
Y1 - 2002/8/16
N2 - The synthesis and characterization of the title trisphenolate ligand are described. From its reaction with manganese(III) three complexes were isolated. The crystal structures revealed one pentacoordinate monomer and two similar dimers with different solvents of crystallization. In the dimers the metal ions are hexacoordinate and connected through bridging of two phenolates. A combination of electrochemistry and EPR spectroscopy showed that, in acetonitrile, the isolated batches were all identical and mainly monomeric, indicating that the mononuclear complex is in equilibrium with the dimer and perhaps also with complexes of higher nuclearity, as suggested by the detection of both the trimer and the tetramer by electrospray ionization mass spectrometry (ESI-MS). The successful use of the monomer batch as an epoxidation catalyst indicated that a high-valent manganese-oxo species can be formed, although it is probably short-lived. This is also suggested by EPR studies of the species formed by electrochemical oxidation of the complex. Upon one-electron oxidation, a manganese(IV) species was formed, which was at least partly converted to another species containing a phenoxy radical.
AB - The synthesis and characterization of the title trisphenolate ligand are described. From its reaction with manganese(III) three complexes were isolated. The crystal structures revealed one pentacoordinate monomer and two similar dimers with different solvents of crystallization. In the dimers the metal ions are hexacoordinate and connected through bridging of two phenolates. A combination of electrochemistry and EPR spectroscopy showed that, in acetonitrile, the isolated batches were all identical and mainly monomeric, indicating that the mononuclear complex is in equilibrium with the dimer and perhaps also with complexes of higher nuclearity, as suggested by the detection of both the trimer and the tetramer by electrospray ionization mass spectrometry (ESI-MS). The successful use of the monomer batch as an epoxidation catalyst indicated that a high-valent manganese-oxo species can be formed, although it is probably short-lived. This is also suggested by EPR studies of the species formed by electrochemical oxidation of the complex. Upon one-electron oxidation, a manganese(IV) species was formed, which was at least partly converted to another species containing a phenoxy radical.
KW - EPR spectroscopy
KW - Manganese
KW - Redox chemistry
KW - Structure elucidation
UR - http://www.scopus.com/inward/record.url?scp=0037119279&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0037119279&partnerID=8YFLogxK
U2 - 10.1002/1521-3765(20020816)8:16<3757::AID-CHEM3757>3.0.CO;2-8
DO - 10.1002/1521-3765(20020816)8:16<3757::AID-CHEM3757>3.0.CO;2-8
M3 - Article
C2 - 12203302
AN - SCOPUS:0037119279
VL - 8
SP - 3757
EP - 3768
JO - Chemistry - A European Journal
JF - Chemistry - A European Journal
SN - 0947-6539
IS - 16
ER -