Bis(acetylacetonato)ruthenium complexes of noninnocent 1,2-dioxolene ligands: Qualitatively different bonding in relation to monoimino and diimino analogues
Coordination compounds Ru(acac)(2)(Q) (acac=acetylacetonate; Q=o-benzoquinone) were prepared as complexes 1 (Q=o-benzoquinone), 2 (Q=3-methoxy-o-benzoquinone), 3 (Q=4-methyl-o-benzoquinone), and 4 (Q=3,5-di-tert-butyl-o-benzoquinone). The structures of 1 and 2 were determined to reveal a Ru(III)/o-benzosemiquinone formulation, supported by analysis of experimental data (spectroscopy, magnetism of 1) and by DFT calculations. The S=1 ground state calculated for 1 stands in contrast to the spin-paired analogues with arylimino-o-benzosemiquinonato and diimino-o-benzoquinone ligands. The close contacts of about 5.3 \AAA possible between semiquinone O atoms of different molecules in the crystal allow for intermolecular spin-spin interactions and an overall complex magnetic behavior. One quasireversible oxidation and two reversible one-electron reductions yielded the corresponding molecular ions, which were characterized by UV-visible-NIR and EPR spectroelectrochemistry in terms of Ru(III)(acac)(2)(Q(0))(+) , Ru(III)(acac)(2)(Q(2-))(-), and Ru(II)(acac)(2)(Q(2-))(2-) descriptions in agreement with DFT results. The use of acceptor-substituted 1,2-dioxolenes resulted in the isolation of ionic species NaRu(acac)(2)(Q) (Na(5); Q=4-chloro-o-benzoquinone) and Na(6) (Q=4-nitro-o-benzoquinone), which were similarly investigated as compounds 1-4. Magnetic susceptibility and EPR results confirm an S=1/2 ground state based on ruthenium(III). The combined studies reveal a remarkable substituent sensitivity, and in comparison to recently analyzed Ru(acac)(2) complexes with o-benzoquinone monoimine and diimine ligands, the all-O-donor-containing new systems are distinguished by a qualitatively different metal-ligand interaction based on closer intermolecular radical-radical contacts and on weaker intramolecular dp-p* interactions.on SciFinder (R)
%0 Journal Article
%1 Das.2011b
%A Das, Dipanwita
%A Sarkar, Biprajit
%A Kumbhakar, Doyel
%A Mondal, Tapan Kumar
%A Mobin, Shaikh M.
%A Fiedler, Jan
%A Urbanos, Francisco A.
%A Jimenez-Aparicio, Reyes
%A Kaim, Wolfgang
%A Lahiri, Goutam Kumar
%D 2011
%J Chemistry (Weinheim an der Bergstrasse, Germany)
%K imported
%N 39
%P 11030--11040
%T Bis(acetylacetonato)ruthenium complexes of noninnocent 1,2-dioxolene ligands: Qualitatively different bonding in relation to monoimino and diimino analogues
%V 17
%X Coordination compounds Ru(acac)(2)(Q) (acac=acetylacetonate; Q=o-benzoquinone) were prepared as complexes 1 (Q=o-benzoquinone), 2 (Q=3-methoxy-o-benzoquinone), 3 (Q=4-methyl-o-benzoquinone), and 4 (Q=3,5-di-tert-butyl-o-benzoquinone). The structures of 1 and 2 were determined to reveal a Ru(III)/o-benzosemiquinone formulation, supported by analysis of experimental data (spectroscopy, magnetism of 1) and by DFT calculations. The S=1 ground state calculated for 1 stands in contrast to the spin-paired analogues with arylimino-o-benzosemiquinonato and diimino-o-benzoquinone ligands. The close contacts of about 5.3 \AAA possible between semiquinone O atoms of different molecules in the crystal allow for intermolecular spin-spin interactions and an overall complex magnetic behavior. One quasireversible oxidation and two reversible one-electron reductions yielded the corresponding molecular ions, which were characterized by UV-visible-NIR and EPR spectroelectrochemistry in terms of Ru(III)(acac)(2)(Q(0))(+) , Ru(III)(acac)(2)(Q(2-))(-), and Ru(II)(acac)(2)(Q(2-))(2-) descriptions in agreement with DFT results. The use of acceptor-substituted 1,2-dioxolenes resulted in the isolation of ionic species NaRu(acac)(2)(Q) (Na(5); Q=4-chloro-o-benzoquinone) and Na(6) (Q=4-nitro-o-benzoquinone), which were similarly investigated as compounds 1-4. Magnetic susceptibility and EPR results confirm an S=1/2 ground state based on ruthenium(III). The combined studies reveal a remarkable substituent sensitivity, and in comparison to recently analyzed Ru(acac)(2) complexes with o-benzoquinone monoimine and diimine ligands, the all-O-donor-containing new systems are distinguished by a qualitatively different metal-ligand interaction based on closer intermolecular radical-radical contacts and on weaker intramolecular dp-p* interactions.on SciFinder (R)
@article{Das.2011b,
abstract = {Coordination compounds [Ru(acac)(2)(Q)] (acac=acetylacetonate; Q=o-benzoquinone) were prepared as complexes 1 (Q=o-benzoquinone), 2 (Q=3-methoxy-o-benzoquinone), 3 (Q=4-methyl-o-benzoquinone), and 4 (Q=3,5-di-tert-butyl-o-benzoquinone). The structures of 1 and 2 were determined to reveal a Ru(III)/o-benzosemiquinone formulation, supported by analysis of experimental data (spectroscopy, magnetism of 1) and by DFT calculations. The S=1 ground state calculated for 1 stands in contrast to the spin-paired analogues with arylimino-o-benzosemiquinonato and diimino-o-benzoquinone ligands. The close contacts of about 5.3 {\AA}A possible between semiquinone O atoms of different molecules in the crystal allow for intermolecular spin-spin interactions and an overall complex magnetic behavior. One quasireversible oxidation and two reversible one-electron reductions yielded the corresponding molecular ions, which were characterized by UV-visible-NIR and EPR spectroelectrochemistry in terms of [Ru(III)(acac)(2)(Q(0))](+) , [Ru(III)(acac)(2)(Q(2-))](-), and [Ru(II)(acac)(2)(Q(2-))](2-) descriptions in agreement with DFT results. The use of acceptor-substituted 1,2-dioxolenes resulted in the isolation of ionic species Na[Ru(acac)(2)(Q)] (Na(5); Q=4-chloro-o-benzoquinone) and Na(6) (Q=4-nitro-o-benzoquinone), which were similarly investigated as compounds 1-4. Magnetic susceptibility and EPR results confirm an S=1/2 ground state based on ruthenium(III). The combined studies reveal a remarkable substituent sensitivity, and in comparison to recently analyzed Ru(acac)(2) complexes with o-benzoquinone monoimine and diimine ligands, the all-O-donor-containing new systems are distinguished by a qualitatively different metal-ligand interaction based on closer intermolecular radical-radical contacts and on weaker intramolecular d\textgreek{p}-\textgreek{p}* interactions.[on SciFinder (R)]},
added-at = {2019-07-15T13:41:23.000+0200},
author = {Das, Dipanwita and Sarkar, Biprajit and Kumbhakar, Doyel and Mondal, Tapan Kumar and Mobin, Shaikh M. and Fiedler, Jan and Urbanos, Francisco A. and Jimenez-Aparicio, Reyes and Kaim, Wolfgang and Lahiri, Goutam Kumar},
biburl = {https://puma.ub.uni-stuttgart.de/bibtex/238c70498ed79bdb7e0e6aa034d1d521a/b_schwederski},
interhash = {efe6ef8ac72511339908c345b5cf6773},
intrahash = {38c70498ed79bdb7e0e6aa034d1d521a},
issn = {1521-3765},
journal = {Chemistry (Weinheim an der Bergstrasse, Germany)},
keywords = {imported},
number = 39,
pages = {11030--11040},
timestamp = {2019-07-15T11:42:10.000+0200},
title = {Bis(acetylacetonato)ruthenium complexes of noninnocent 1,2-dioxolene ligands: Qualitatively different bonding in relation to monoimino and diimino analogues},
volume = 17,
year = 2011
}