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פותח על ידי קלירמאש פתרונות בע"מ -
DFT study of the structure and reactivity of the terminal Pt(IV)-OxO complex bearing no electron-withdrawing ligands
Year:
2010
Authors :
פוברנוב, ילנה
;
.
Volume :
132
Co-Authors:
Efremenko, I., Department of Organic Chemistry, Weizmann Institute of Science, Rehovot 76000, Israel
Poverenov, E., Department of Organic Chemistry, Weizmann Institute of Science, Rehovot 76000, Israel
Martin, J.M.L., Department of Organic Chemistry, Weizmann Institute of Science, Rehovot 76000, Israel
Milstein, D., Department of Organic Chemistry, Weizmann Institute of Science, Rehovot 76000, Israel
Facilitators :
From page:
14886
To page:
14900
(
Total pages:
15
)
Abstract:
The recently published [(PCN)Pt=O]+ complex is interesting as a unique example of a stable d6 terminal transition metal oxo complex not stabilized by electron withdrawing ligands and as a model of oxo complexes frequently implicated as key intermediates in various processes of oxygen transfer. In the present work, we report an extensive DFT study of its geometric and electronic structure, composition in solution, and reactivity. The thermodynamic data and calculated 195R NMR chemical shifts reveal that one solvent molecule is weakly coordinated to the complex in acetone solution. This ancillary ligand is responsible for the diamagnetic state of the complex, retards intramolecular oxygen transfer, and facilitates CO oxidation. Chemical transformations of the coordinated acetone molecule, coordination of other ancillary ligands present in the reaction mixture, and protonation of the Pt-oxo group in nonacidic media are excluded based on thermodynamic or kinetic considerations. Bonding of the terminal oxo ligand with strong electrophiles presents the key interaction in the mechanisms of intramolecular oxygen insertion into the R-P bond, in CO oxidation and in water activation mediated by microsolvation. Low affinity of the terminal oxo ligand toward "soft" covalent interactions brings about intermediate formation of agostic hydrido and hydroxo complexes along the reaction pathway of dihydrogen oxidation. Stabilization of the R-oxo bonding is attributed to bending of the terminal oxo ligand out of the plane of the complex and to significant transfer of electron density from compact low lying R 5d orbitais to more diffuse 6s and 6p orbitais. © 2010 American Chemical Society.
Note:
Related Files :
acetone
chemical binding
Models, Molecular
NMR chemical shifts
oxidation
platinum complex
Reaction intermediates
עוד תגיות
תוכן קשור
More details
DOI :
10.1021/ja105197x
Article number:
Affiliations:
Database:
סקופוס
Publication Type:
מאמר
;
.
Language:
אנגלית
Editors' remarks:
ID:
24405
Last updated date:
02/03/2022 17:27
Creation date:
17/04/2018 00:07
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Scientific Publication
DFT study of the structure and reactivity of the terminal Pt(IV)-OxO complex bearing no electron-withdrawing ligands
132
Efremenko, I., Department of Organic Chemistry, Weizmann Institute of Science, Rehovot 76000, Israel
Poverenov, E., Department of Organic Chemistry, Weizmann Institute of Science, Rehovot 76000, Israel
Martin, J.M.L., Department of Organic Chemistry, Weizmann Institute of Science, Rehovot 76000, Israel
Milstein, D., Department of Organic Chemistry, Weizmann Institute of Science, Rehovot 76000, Israel
DFT study of the structure and reactivity of the terminal Pt(IV)-OxO complex bearing no electron-withdrawing ligands
The recently published [(PCN)Pt=O]+ complex is interesting as a unique example of a stable d6 terminal transition metal oxo complex not stabilized by electron withdrawing ligands and as a model of oxo complexes frequently implicated as key intermediates in various processes of oxygen transfer. In the present work, we report an extensive DFT study of its geometric and electronic structure, composition in solution, and reactivity. The thermodynamic data and calculated 195R NMR chemical shifts reveal that one solvent molecule is weakly coordinated to the complex in acetone solution. This ancillary ligand is responsible for the diamagnetic state of the complex, retards intramolecular oxygen transfer, and facilitates CO oxidation. Chemical transformations of the coordinated acetone molecule, coordination of other ancillary ligands present in the reaction mixture, and protonation of the Pt-oxo group in nonacidic media are excluded based on thermodynamic or kinetic considerations. Bonding of the terminal oxo ligand with strong electrophiles presents the key interaction in the mechanisms of intramolecular oxygen insertion into the R-P bond, in CO oxidation and in water activation mediated by microsolvation. Low affinity of the terminal oxo ligand toward "soft" covalent interactions brings about intermediate formation of agostic hydrido and hydroxo complexes along the reaction pathway of dihydrogen oxidation. Stabilization of the R-oxo bonding is attributed to bending of the terminal oxo ligand out of the plane of the complex and to significant transfer of electron density from compact low lying R 5d orbitais to more diffuse 6s and 6p orbitais. © 2010 American Chemical Society.
Scientific Publication
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