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Title: Copper(I) Complex O(2)-Reactivity With a N(3)S Thioether Ligand: a Copper-Dioxygen Adduct Including Sulfur Ligation, Ligand Oxygenation, And Comparisons With All Nitrogen Ligand Analogues

Abstract

In order to contribute to an understanding of the effects of thioether sulfur ligation in copper-O(2) reactivity, the tetradentate ligands L(N3S) (2-ethylthio-N,N-bis(pyridin-2-yl)methylethanamine) and L(N3S')(2-ethylthio-N,N-bis(pyridin-2-yl)ethylethanamine) have been synthesized. Corresponding copper(I) complexes, [CuI(L(N3S))]ClO(4) (1-ClO(4)), [CuI(L(N3S))]B(C(6)F(5))(4) (1-B(C(6)F(5))(4)), and [CuI(L(N3S'))]ClO(4) (2), were generated, and their redox properties, CO binding, and O(2)-reactivity were compared to the situation with analogous compounds having all nitrogen donor ligands, [CuI(TMPA)(MeCN)](+) and [Cu(I)(PMAP)](+) (TMPA = tris(2-pyridylmethyl)amine; PMAP = bis[2-(2-pyridyl)ethyl]-(2-pyridyl)methylamine). X-ray structures of 1-B(C(6)F(5))(4), a dimer, and copper(II) complex [Cu(II)(L(N3S))(MeOH)](ClO(4))(2) (3) were obtained; the latter possesses axial thioether coordination. At low temperature in CH(2)Cl(2), acetone, or 2-methyltetrahydrofuran (MeTHF), 1 reacts with O(2) and generates an adduct formulated as an end-on peroxodicopper(II) complex [{l_brace}Cu(II)(L(N3S)){r_brace}(2)(mu-1,2-O(2)(2-))](2+) (4){lambda}(max) = 530 (epsilon approximately 9200 M(-1) cm(-1)) and 605 nm (epsilon approximately 11,800 M(-1) cm(-1)); the number and relative intensity of LMCT UV-vis bands vary from those for [{l_brace}Cu(II)(TMPA){r_brace}(2)(O(2)(2-))](2+) {lambda}(max) = 524 nm (epsilon = 11,300 M(-1) cm(-1)) and 615 nm (epsilon = 5800 M(-1) cm(-1)) and are ascribed to electronic structure variation due to coordination geometry changes with the L(N3S) ligand. Resonance Raman spectroscopy confirms the end-on peroxo-formulation {nu}(O-O) = 817 cm(-1) (16-18O(2) Delta = 46 cm(-1)) and nu(Cu-O) = 545 cm(-1) (16-18O(2) Delta = 26more » cm(-1)); these values are lower in energy than those for [{l_brace}Cu(II)(TMPA){r_brace}(2)(O(2)(2-))](2+) {nu}(Cu-O) = 561 cm(-1) and nu(O-O) = 827 cm(-1) and can be attributed to less electron density donation from the peroxide pi* orbitals to the Cu(II) ion. Complex 4 is the first copper-dioxygen adduct with thioether ligation; direct evidence comes from EXAFS spectroscopy {l_brace}Cu K-edge; Cu-S = 2.4 Angstrom{r_brace}. Following a [Cu(I)(L(N3S))](+)/O(2) reaction and warming, the L(N3S) thioether ligand is oxidized to the sulfoxide in a reaction modeling copper monooxygenase activity. By contrast, 2 is unreactive toward dioxygen probably due to its significantly increased Cu(II)/Cu(I) redox potential, an effect of ligand chelate ring size (in comparison to 1). Discussion of the relevance of the chemistry to copper enzyme O(2)-activation, and situations of biological stress involving methionine oxidation, is provided.« less

Authors:
; ; ; ; ; ; ; ; ; ; ;
Publication Date:
Research Org.:
Stanford Linear Accelerator Center (SLAC)
Sponsoring Org.:
USDOE
OSTI Identifier:
953935
Report Number(s):
SLAC-REPRINT-2009-457
Journal ID: ISSN 0020-1669; INOCAJ; TRN: US201004%%672
DOE Contract Number:  
AC02-76SF00515
Resource Type:
Journal Article
Journal Name:
Inorg. Chem. 46:6056,2007
Additional Journal Information:
Journal Volume: 46; Journal Issue: 15; Journal ID: ISSN 0020-1669
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; ACETONE; ADDUCTS; BIOLOGICAL STRESS; CHELATES; CHEMISTRY; COPPER COMPLEXES; COPPER; ELECTRON DENSITY; ELECTRONIC STRUCTURE; ENZYMES; LIGANDS; METHIONINE; NITROGEN; ORGANIC SULFUR COMPOUNDS; OXIDATION; PEROXIDES; RAMAN SPECTROSCOPY; REACTIVITY; REDOX POTENTIAL; RESONANCE; SIMULATION; SPECTROSCOPY; SULFOXIDES; SULFUR; TEMPERATURE RANGE 0065-0273 K; VARIATIONS; Other,OTHER, CHEM

Citation Formats

Lee, D -H, Hatcher, L Q, Vance, M A, Sarangi, R, Milligan, A E, Sarjeant, A A Narducci, Incarvito, C D, Rheingold, A L, Hodgson, K O, Hedman, B, Solomon, E I, and Karlin, K D. Copper(I) Complex O(2)-Reactivity With a N(3)S Thioether Ligand: a Copper-Dioxygen Adduct Including Sulfur Ligation, Ligand Oxygenation, And Comparisons With All Nitrogen Ligand Analogues. United States: N. p., 2009. Web.
Lee, D -H, Hatcher, L Q, Vance, M A, Sarangi, R, Milligan, A E, Sarjeant, A A Narducci, Incarvito, C D, Rheingold, A L, Hodgson, K O, Hedman, B, Solomon, E I, & Karlin, K D. Copper(I) Complex O(2)-Reactivity With a N(3)S Thioether Ligand: a Copper-Dioxygen Adduct Including Sulfur Ligation, Ligand Oxygenation, And Comparisons With All Nitrogen Ligand Analogues. United States.
Lee, D -H, Hatcher, L Q, Vance, M A, Sarangi, R, Milligan, A E, Sarjeant, A A Narducci, Incarvito, C D, Rheingold, A L, Hodgson, K O, Hedman, B, Solomon, E I, and Karlin, K D. Wed . "Copper(I) Complex O(2)-Reactivity With a N(3)S Thioether Ligand: a Copper-Dioxygen Adduct Including Sulfur Ligation, Ligand Oxygenation, And Comparisons With All Nitrogen Ligand Analogues". United States.
@article{osti_953935,
title = {Copper(I) Complex O(2)-Reactivity With a N(3)S Thioether Ligand: a Copper-Dioxygen Adduct Including Sulfur Ligation, Ligand Oxygenation, And Comparisons With All Nitrogen Ligand Analogues},
author = {Lee, D -H and Hatcher, L Q and Vance, M A and Sarangi, R and Milligan, A E and Sarjeant, A A Narducci and Incarvito, C D and Rheingold, A L and Hodgson, K O and Hedman, B and Solomon, E I and Karlin, K D},
abstractNote = {In order to contribute to an understanding of the effects of thioether sulfur ligation in copper-O(2) reactivity, the tetradentate ligands L(N3S) (2-ethylthio-N,N-bis(pyridin-2-yl)methylethanamine) and L(N3S')(2-ethylthio-N,N-bis(pyridin-2-yl)ethylethanamine) have been synthesized. Corresponding copper(I) complexes, [CuI(L(N3S))]ClO(4) (1-ClO(4)), [CuI(L(N3S))]B(C(6)F(5))(4) (1-B(C(6)F(5))(4)), and [CuI(L(N3S'))]ClO(4) (2), were generated, and their redox properties, CO binding, and O(2)-reactivity were compared to the situation with analogous compounds having all nitrogen donor ligands, [CuI(TMPA)(MeCN)](+) and [Cu(I)(PMAP)](+) (TMPA = tris(2-pyridylmethyl)amine; PMAP = bis[2-(2-pyridyl)ethyl]-(2-pyridyl)methylamine). X-ray structures of 1-B(C(6)F(5))(4), a dimer, and copper(II) complex [Cu(II)(L(N3S))(MeOH)](ClO(4))(2) (3) were obtained; the latter possesses axial thioether coordination. At low temperature in CH(2)Cl(2), acetone, or 2-methyltetrahydrofuran (MeTHF), 1 reacts with O(2) and generates an adduct formulated as an end-on peroxodicopper(II) complex [{l_brace}Cu(II)(L(N3S)){r_brace}(2)(mu-1,2-O(2)(2-))](2+) (4){lambda}(max) = 530 (epsilon approximately 9200 M(-1) cm(-1)) and 605 nm (epsilon approximately 11,800 M(-1) cm(-1)); the number and relative intensity of LMCT UV-vis bands vary from those for [{l_brace}Cu(II)(TMPA){r_brace}(2)(O(2)(2-))](2+) {lambda}(max) = 524 nm (epsilon = 11,300 M(-1) cm(-1)) and 615 nm (epsilon = 5800 M(-1) cm(-1)) and are ascribed to electronic structure variation due to coordination geometry changes with the L(N3S) ligand. Resonance Raman spectroscopy confirms the end-on peroxo-formulation {nu}(O-O) = 817 cm(-1) (16-18O(2) Delta = 46 cm(-1)) and nu(Cu-O) = 545 cm(-1) (16-18O(2) Delta = 26 cm(-1)); these values are lower in energy than those for [{l_brace}Cu(II)(TMPA){r_brace}(2)(O(2)(2-))](2+) {nu}(Cu-O) = 561 cm(-1) and nu(O-O) = 827 cm(-1) and can be attributed to less electron density donation from the peroxide pi* orbitals to the Cu(II) ion. Complex 4 is the first copper-dioxygen adduct with thioether ligation; direct evidence comes from EXAFS spectroscopy {l_brace}Cu K-edge; Cu-S = 2.4 Angstrom{r_brace}. Following a [Cu(I)(L(N3S))](+)/O(2) reaction and warming, the L(N3S) thioether ligand is oxidized to the sulfoxide in a reaction modeling copper monooxygenase activity. By contrast, 2 is unreactive toward dioxygen probably due to its significantly increased Cu(II)/Cu(I) redox potential, an effect of ligand chelate ring size (in comparison to 1). Discussion of the relevance of the chemistry to copper enzyme O(2)-activation, and situations of biological stress involving methionine oxidation, is provided.},
doi = {},
url = {https://www.osti.gov/biblio/953935}, journal = {Inorg. Chem. 46:6056,2007},
issn = {0020-1669},
number = 15,
volume = 46,
place = {United States},
year = {2009},
month = {6}
}