EPR/ENDOR detection of stable titanium(III) and titanium(IV) radical products generated by single electron transfer from (iso-PrO)3TiCH3
M. Moscherosch, and W. Kaim. Journal of the Chemical Society, Perkin Transactions 2: Physical Organic Chemistry, (1992)
Abstract
Single-electron-transfer reactions between the stereoselective carbanion source methyltriisopropoxytitanium(IV) as donor and a-diimines, ketones, or a-dicarbonyls as p acceptor substrates exhibit a dichotomy with respect to the ESR-detectable paramagnetic 'escape' products. Substrates with very neg. redn. potentials such as 2,2'-bipyridine yield Ti(III) species, whereas more easily reducible mols. such as dinucleating 3,6-bis(2-pyridyl)-1,2,4,5-tetrazine react to yield ESR-detectable Ti(IV) complexes of the corresponding anion radicals. A very stable paramagnetic product was isolated from the reaction between 3,5-di-tert-butyl-o-quinone (dtbq) and (Me2CHO)3TiMe; this first thermally stable, but apparently configurationally labile, Ti(IV) semiquinone complex (dtbq-1)Ti(OCHMe2)3.bul. was studied by UV-VIS-NIR absorption and ESR/ENDOR spectroscopy. on SciFinder(R)
%0 Journal Article
%1 Moscherosch.1992
%A Moscherosch, Michael
%A Kaim, Wolfgang.
%D 1992
%J Journal of the Chemical Society, Perkin Transactions 2: Physical Organic Chemistry
%K ENDOR ESR ESR;titanium complex dicarbonyl donor;semiquinone electron methyltriisopropoxytitanium;diimine methyltriisopropoxytitanium;ketone methyltriisopropoxytitanium;methyltriisopropoxytitanium prepn radical single stable titanium transfer
%N 9
%P 1493--1496
%T EPR/ENDOR detection of stable titanium(III) and titanium(IV) radical products generated by single electron transfer from (iso-PrO)3TiCH3
%X Single-electron-transfer reactions between the stereoselective carbanion source methyltriisopropoxytitanium(IV) as donor and a-diimines, ketones, or a-dicarbonyls as p acceptor substrates exhibit a dichotomy with respect to the ESR-detectable paramagnetic 'escape' products. Substrates with very neg. redn. potentials such as 2,2'-bipyridine yield Ti(III) species, whereas more easily reducible mols. such as dinucleating 3,6-bis(2-pyridyl)-1,2,4,5-tetrazine react to yield ESR-detectable Ti(IV) complexes of the corresponding anion radicals. A very stable paramagnetic product was isolated from the reaction between 3,5-di-tert-butyl-o-quinone (dtbq) and (Me2CHO)3TiMe; this first thermally stable, but apparently configurationally labile, Ti(IV) semiquinone complex (dtbq-1)Ti(OCHMe2)3.bul. was studied by UV-VIS-NIR absorption and ESR/ENDOR spectroscopy. on SciFinder(R)
@article{Moscherosch.1992,
abstract = {Single-electron-transfer reactions between the stereoselective carbanion source methyltriisopropoxytitanium(IV) as donor and \textgreek{a}-diimines, ketones, or \textgreek{a}-dicarbonyls as \textgreek{p} acceptor substrates exhibit a dichotomy with respect to the ESR-detectable paramagnetic 'escape' products. Substrates with very neg. redn. potentials such as 2,2'-bipyridine yield Ti(III) species, whereas more easily reducible mols. such as dinucleating 3,6-bis(2-pyridyl)-1,2,4,5-tetrazine react to yield ESR-detectable Ti(IV) complexes of the corresponding anion radicals. A very stable paramagnetic product was isolated from the reaction between 3,5-di-tert-butyl-o-quinone (dtbq) and (Me2CHO)3TiMe; this first thermally stable, but apparently configurationally labile, Ti(IV) semiquinone complex [(dtbq-1)Ti(OCHMe2)3].bul. was studied by UV-VIS-NIR absorption and ESR/ENDOR spectroscopy. [on SciFinder(R)]},
added-at = {2022-06-15T11:26:56.000+0200},
author = {Moscherosch, Michael and Kaim, Wolfgang.},
biburl = {https://puma.ub.uni-stuttgart.de/bibtex/2e60562648ed6280a92f3b4ce06c07f90/huebleriac},
interhash = {5efee7c4ab383bb0c2eea5c54716beb3},
intrahash = {e60562648ed6280a92f3b4ce06c07f90},
issn = {0300-9580},
journal = {Journal of the Chemical Society, Perkin Transactions 2: Physical Organic Chemistry},
keywords = {ENDOR ESR ESR;titanium complex dicarbonyl donor;semiquinone electron methyltriisopropoxytitanium;diimine methyltriisopropoxytitanium;ketone methyltriisopropoxytitanium;methyltriisopropoxytitanium prepn radical single stable titanium transfer},
number = 9,
pages = {1493--1496},
timestamp = {2022-06-15T09:26:56.000+0200},
title = {EPR/ENDOR detection of stable titanium(III) and titanium(IV) radical products generated by single electron transfer from (iso-PrO)3TiCH3},
year = 1992
}