Advanced

Synthesis of a Tetradentate Pyridyl/Quinoline Ligand and its Iron(II) Complex

Kugler, Benedikt LU (2016) KEMP32 20152
Department of Chemistry
Abstract
High-spin oxoiron(IV) complexes are often postulated as intermediates in the catalytic cycle of nonheme iron oxygenases. Their C−H bond cleaving ability is attributed to the highly reactive quintet (S = 2) spin state. However, as of today, there are very few synthetic complexes that enforce the high spin state and even fewer that retain a high reactivity.
In this study, a new tripodal tetradentate {N4} donor ligand has been synthesized, based on the TPA (TPA = tris(2-pyridylmethyl)amine) framework, 2-(Pyridin-2-yl)-N-(pyridin-2-ylmethyl)-N-(quinolin-2-ylmethyl)ethane-1-amine (L1 (5)), where one pyridyl arm has been substituted by a corresponding quinoline-containing moiety and a methylene linker was introduced to another. The ligand was... (More)
High-spin oxoiron(IV) complexes are often postulated as intermediates in the catalytic cycle of nonheme iron oxygenases. Their C−H bond cleaving ability is attributed to the highly reactive quintet (S = 2) spin state. However, as of today, there are very few synthetic complexes that enforce the high spin state and even fewer that retain a high reactivity.
In this study, a new tripodal tetradentate {N4} donor ligand has been synthesized, based on the TPA (TPA = tris(2-pyridylmethyl)amine) framework, 2-(Pyridin-2-yl)-N-(pyridin-2-ylmethyl)-N-(quinolin-2-ylmethyl)ethane-1-amine (L1 (5)), where one pyridyl arm has been substituted by a corresponding quinoline-containing moiety and a methylene linker was introduced to another. The ligand was analyzed by 1H and
13C NMR, as well as high resolution mass spectrometry.
The complex [FeII(CH3CN)(L1)]2+ was synthesized and characterized by 1H NMR, UV-vis spectroscopy and high resolution mass spectrometry. The corresponding ruthenium complex [RuII(CH3CN)(L1)]2+ was synthesized and characterized by
1H NMR to gain further insight into the metal-ligand binding. An attempt was made to obtain the ferryl complex [FeIV(O)(L)]2+ by oxidation with iodosylbenzene, but the desired species could not be observed by spectroscopic means. (Less)
Popular Abstract
Metal centers play an important role in biological systems. As parts of enzymes, they catalyze (i.e. speed up) a number of essential reactions. These reactions are often accompanied by various changes at the metal center. Therefore, an analysis of the sub-steps may grant further insight into the biological process. Because these snapshots cannot be isolated from nature, it is the task of Bioinorganic Chemistry to create model systems. The goal of this project work was to synthesize one such model system of a crucial intermediate found in nonheme iron oxygenases, namely an iron(IV) complex with a terminally bound oxido (O2-) ligand, and to assess its electronic state.
Please use this url to cite or link to this publication:
author
Kugler, Benedikt LU
supervisor
organization
course
KEMP32 20152
year
type
L3 - Miscellaneous, Projetcs etc.
subject
keywords
inorganic chemistry, oxygenases, high spin, oorganisk kemi, iron, KEMP32, bioinorganic chemistry
language
English
id
8521229
date added to LUP
2016-02-01 16:23:24
date last changed
2016-02-01 16:23:24
@misc{8521229,
  abstract     = {High-spin oxoiron(IV) complexes are often postulated as intermediates in the catalytic cycle of nonheme iron oxygenases. Their C−H bond cleaving ability is attributed to the highly reactive quintet (S = 2) spin state. However, as of today, there are very few synthetic complexes that enforce the high spin state and even fewer that retain a high reactivity. 
In this study, a new tripodal tetradentate {N4} donor ligand has been synthesized, based on the TPA (TPA = tris(2-pyridylmethyl)amine) framework, 2-(Pyridin-2-yl)-N-(pyridin-2-ylmethyl)-N-(quinolin-2-ylmethyl)ethane-1-amine (L1 (5)), where one pyridyl arm has been substituted by a corresponding quinoline-containing moiety and a methylene linker was introduced to another. The ligand was analyzed by 1H and 
13C NMR, as well as high resolution mass spectrometry.
The complex [FeII(CH3CN)(L1)]2+ was synthesized and characterized by 1H NMR, UV-vis spectroscopy and high resolution mass spectrometry. The corresponding ruthenium complex [RuII(CH3CN)(L1)]2+ was synthesized and characterized by 
1H NMR to gain further insight into the metal-ligand binding. An attempt was made to obtain the ferryl complex [FeIV(O)(L)]2+ by oxidation with iodosylbenzene, but the desired species could not be observed by spectroscopic means.},
  author       = {Kugler, Benedikt},
  keyword      = {inorganic chemistry,oxygenases,high spin,oorganisk kemi,iron,KEMP32,bioinorganic chemistry},
  language     = {eng},
  note         = {Student Paper},
  title        = {Synthesis of a Tetradentate Pyridyl/Quinoline Ligand and its Iron(II) Complex},
  year         = {2016},
}