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Coordination Chemistry of Highly Hemilabile Bidentate Sulfoxide N-Heterocyclic Carbenes with Palladium(II)
- Source :
- Chemistry-An Asian Journal, 9(12), 3498-3510. John Wiley and Sons Ltd
- Publication Year :
- 2014
-
Abstract
- Imidazolium salts, [RS(O) CH2 (C3 H3 N2 )Mes]Cl (R=Me (L1 a), Ph (L1 b)); Mes=mesityl), make convenient carbene precursors. Palladation of L1 a affords the monodentate dinuclear complex, [(PdCl2 {MeS(O)CH2 (C3 H2 N2 )Mes})2 ] (2 a), which is converted into trans-[PdCl2 (NHC)2 ] (trans-4 a; N-heterocyclic carbene) with two rotamers in anti and syn configurations. Complex trans-4 a can isomerize into cis-4 a(anti) at reflux in acetonitrile. Abstraction of chlorides from 4 a or 4 b leads to the formation of a new dication: trans-[Pd{RS(O)CH2 (C3 H2 N2 )Mes}2 ](PF6 )2 (R=Me (5 a), Ph (5 b)). The X-ray structure of 5 a provides evidence that the two bidentate SO NHC ligands at palladium(II) are in square-planar geometry. Two sulfoxides are sulfur- and oxygen-bound, and constitute five- and six-membered chelate rings with the metal center, respectively. In acetonitrile, complexes 5 a or 5 b spontaneously transform into cis-[Pd(NHC)2 (NCMe)2 ](PF6 )2 . Similar studies of thioether-NHCs have also been examined for comparison. The results indicate that sulfoxides are more labile than thioethers.
Details
- Language :
- English
- ISSN :
- 18614728
- Database :
- OpenAIRE
- Journal :
- Chemistry-An Asian Journal, 9(12), 3498-3510. John Wiley and Sons Ltd
- Accession number :
- edsair.doi.dedup.....4c740b855e2b15f617b7a32279f77781