The temp.-dependent intramol. metal/ligand electron transfer equil. (L)CuII(Q2-).dblharw.(L)Cu1(Q·-) was quant. analyzed by EPR as a function of the noninnocent o-quinonoid ligand Q and of the co-ligand L. Suitable co-ligands were 1-methyl-(2-methylthiomethyl)-1H-benzimidazole and 1-diphenylphosphino-2-dimethylaminoethane (dde) which can tolerate both copper oxidn. states. EPR hyperfine data were extd. for a variety of alkyl- and methoxy-substituted o-semiquinones and their copper(I) complexes in soln. A close match of Q and Cu redox orbitals is essential for observing the redox isomer equil. which was similarly reported for aminoxidase enzymes. Efforts to isolate the mixed-ligand compds. from soln. failed due to coordination disproportionation. The new Cu(dde)2(ClO4) was structurally characterized with comparable Cu-N and Cu-P distances of 2.24-2.27 \AA and a P-Cu-P angle of 142.41(5)°, the 2+2 coordination pattern could be reproduced by DFT calcns. on SciFinder(R)
%0 Journal Article
%1 Kaim.2002c
%A Kaim, Wolfgang
%A Wanner, Matthias
%A Knodler, Axel
%A Zalis, Stanislav.
%D 2002
%J Inorganica Chimica Acta
%K EPR;crystal aminoethylphosphine catecholato complex copper electron prepn semiquinonato structure structure;copper transfer
%P 163--172
%R 10.1016/S0020-1693(02)01081-2
%T Copper complexes with non-innocent ligands: Probing CuII/catecholato-CuI/o-semiquinonato redox isomer equilibria with EPR spectroscopy
%V 337
%X The temp.-dependent intramol. metal/ligand electron transfer equil. (L)CuII(Q2-).dblharw.(L)Cu1(Q·-) was quant. analyzed by EPR as a function of the noninnocent o-quinonoid ligand Q and of the co-ligand L. Suitable co-ligands were 1-methyl-(2-methylthiomethyl)-1H-benzimidazole and 1-diphenylphosphino-2-dimethylaminoethane (dde) which can tolerate both copper oxidn. states. EPR hyperfine data were extd. for a variety of alkyl- and methoxy-substituted o-semiquinones and their copper(I) complexes in soln. A close match of Q and Cu redox orbitals is essential for observing the redox isomer equil. which was similarly reported for aminoxidase enzymes. Efforts to isolate the mixed-ligand compds. from soln. failed due to coordination disproportionation. The new Cu(dde)2(ClO4) was structurally characterized with comparable Cu-N and Cu-P distances of 2.24-2.27 \AA and a P-Cu-P angle of 142.41(5)°, the 2+2 coordination pattern could be reproduced by DFT calcns. on SciFinder(R)
@article{Kaim.2002c,
abstract = {The temp.-dependent intramol. metal/ligand electron transfer equil. (L)CuII(Q2-).dblharw.(L)Cu1(Q·-) was quant. analyzed by EPR as a function of the noninnocent o-quinonoid ligand Q and of the co-ligand L. Suitable co-ligands were 1-methyl-(2-methylthiomethyl)-1H-benzimidazole and 1-diphenylphosphino-2-dimethylaminoethane (dde) which can tolerate both copper oxidn. states. EPR hyperfine data were extd. for a variety of alkyl- and methoxy-substituted o-semiquinones and their copper(I) complexes in soln. A close match of Q and Cu redox orbitals is essential for observing the redox isomer equil. which was similarly reported for aminoxidase enzymes. Efforts to isolate the mixed-ligand compds. from soln. failed due to coordination disproportionation. The new [Cu(dde)2](ClO4) was structurally characterized with comparable Cu-N and Cu-P distances of 2.24-2.27 {\AA} and a P-Cu-P angle of 142.41(5)°, the 2+2 coordination pattern could be reproduced by DFT calcns. [on SciFinder(R)]},
added-at = {2022-06-15T11:26:56.000+0200},
author = {Kaim, Wolfgang and Wanner, Matthias and Knodler, Axel and Zalis, Stanislav.},
biburl = {https://puma.ub.uni-stuttgart.de/bibtex/2e473b59c8007f94ce232c0dac70e1e00/huebleriac},
doi = {10.1016/S0020-1693(02)01081-2},
interhash = {0f69f897905b527867e5d74d2bbf0314},
intrahash = {e473b59c8007f94ce232c0dac70e1e00},
issn = {0020-1693},
journal = {Inorganica Chimica Acta},
keywords = {EPR;crystal aminoethylphosphine catecholato complex copper electron prepn semiquinonato structure structure;copper transfer},
pages = {163--172},
timestamp = {2022-06-15T09:26:56.000+0200},
title = {Copper complexes with non-innocent ligands: Probing CuII/catecholato-CuI/o-semiquinonato redox isomer equilibria with EPR spectroscopy},
volume = 337,
year = 2002
}