Where is the unpaired electron density? A combined experimental and theoretical finding on the geometric and electronic structures of the Co(III) and Mn(IV) complexes of the unsymmetrical non-innocent pincer ONS ligand
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61388963%3A_____%2F22%3A00563490" target="_blank" >RIV/61388963:_____/22:00563490 - isvavai.cz</a>
Alternative codes found
RIV/61989592:15640/22:73618727
Result on the web
<a href="https://doi.org/10.1039/D2DT01868C" target="_blank" >https://doi.org/10.1039/D2DT01868C</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.1039/d2dt01868c" target="_blank" >10.1039/d2dt01868c</a>
Alternative languages
Result language
angličtina
Original language name
Where is the unpaired electron density? A combined experimental and theoretical finding on the geometric and electronic structures of the Co(III) and Mn(IV) complexes of the unsymmetrical non-innocent pincer ONS ligand
Original language description
The tridentate pincer ligand [LONS]3− with the ONS donor set was generated in situ by cleaving the disulfane linkage of the pristine redox-active H4Sar(AP/AP) ligand during the complexation reaction with Co(II) and Mn(II) salts in the presence of air and Et3N. X-ray crystal structure analysis of the Co complex (1) and Mn complex (2) revealed that both the complexes were neutral in charge and six-coordinate with the meridional coordination of the two pincer [LONS]n− ligands. The Co ion was in the trivalent state, while the Mn ion was in the tetravalent state. Thus, the generated two pincer [LONS]3− ligands were non-innocent and cumulatively were in trinegative and tetranegative charges for the respective complexes. The intraligand bond distances of the coordinating ligands in each complex were similar, implying the same oxidation/electronic structure of the two ligating units. Variable-temperature magnetic susceptibility measurements revealed an S = 1/2 ground state for each complex. X-band EPR measurements unambiguously established the presence of a ligand-based unpaired electron in complex 1, and in complex 2, the unpaired electron was at the Mn centre. DFT-based theoretical calculations suggested the three-electron oxidation of the two ligating units in complex 1. Two iminosemiquinone radicals were of opposite spins (α-spin and β-spin) and a thiyl radical in either α-spin or β-spin was delocalized between two sulfur atoms. Thus, the antiferromagnetic coupling among the two opposite spins provided an S = 1/2 ground state and resulted in the radical-based EPR spectrum. In complex 2, each ligating pincer unit contained an iminosemiquinone radical that interacted antiferromagnetically with the Mn(IV)-based three unpaired electrons. This rendered a doublet ground state with the residual electron density located at the Mn center.
Czech name
—
Czech description
—
Classification
Type
J<sub>imp</sub> - Article in a specialist periodical, which is included in the Web of Science database
CEP classification
—
OECD FORD branch
10403 - Physical chemistry
Result continuities
Project
Result was created during the realization of more than one project. More information in the Projects tab.
Continuities
I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace
Others
Publication year
2022
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
Dalton Transactions
ISSN
1477-9226
e-ISSN
1477-9234
Volume of the periodical
51
Issue of the periodical within the volume
43
Country of publishing house
GB - UNITED KINGDOM
Number of pages
10
Pages from-to
16723-16732
UT code for WoS article
000872130300001
EID of the result in the Scopus database
—