Experimental and Computational Determination of a M-Cl Homolytic Bond Dissociation Free Energy: Mn(III)Cl-Mediated C-H Cleavage and Chlorination.
J Am Chem Soc
; 145(24): 13384-13391, 2023 Jun 21.
Article
em En
| MEDLINE
| ID: mdl-37279382
ABSTRACT
This study confirms the hypothesis that [MnCl3(OPPh3)2] (1) and acetonitrile-solvated MnCl3 (i.e., [MnCl3(MeCN)x]) can be used as synthons to prepare Mn(III) chloride complexes with facially coordinating ligands. This was achieved through the preparation and characterization of six new {MnIIICl} complexes using anionic ligands TpH (tris(pyrazolyl)borate) and TpMe (tris(3,5-dimethylpyrazolyl)borate). The MnIII-chloride dissociation and association equilibria (Keq) and MnIII/II reduction potentials were quantified in DCM. These two thermochemical parameters (Keq and E1/2), in addition to the known Cl-atom reduction potential in DCM, enabled the quantification of the Mn-Cl bond dissociation (homolysis) free energy of 21 and 23 ± 7 kcal/mol at room temperature for R = H and Me, respectively. These are in reasonable agreement with the bond dissociation free energy (BDFEM-Cl) of 34 ± 6 kcal/mol calculated using density functional theory. The BDFEM-Cl of 1 was also calculated (25 ± 6 kcal/mol). These energies were used in predictive C-H bond reactivity.
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1
Coleções:
01-internacional
Base de dados:
MEDLINE
Idioma:
En
Revista:
J Am Chem Soc
Ano de publicação:
2023
Tipo de documento:
Article
País de afiliação:
Estados Unidos