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Cathodic behaviour of dicationic imidazolium bromides: the role of the spacer

Authors :
Daniele Rocco
Isabella Chiarotto
Marta Feroci
Leonardo Mattiello
Fabiana Pandolfi
Francesca D'Anna
Carla Rizzo
Daniele Rocco, Isabella Chiarotto, Francesca D'Anna, Leonardo Mattiello, Fabiana Pandolfi, Carla Rizzo, Marta Feroci
Publication Year :
2019
Publisher :
Wiley-VCH Verlag, 2019.

Abstract

The cathodic reduction of dicationic imidazolium bromides, whose spacer is either an aliphatic chain or a xylyl group, leads to the formation of the corresponding N-heterocyclic carbenes (NHCs), which were isolated as the corresponding thiones, after reaction with elemental sulfur. The behaviour of the dications was compared with the corresponding monocations. The behaviour of dicarbenes depends on the nature of the spacer. This study evidenced that dicarbenes deriving from xylyl dications are less stable than the corresponding aliphatic ones (giving lower yields in thiones), due to a debenzylation reaction. On the other hand, the yields in thiones starting from aliphatic dications are higher than the corresponding monocations, suggesting a cooperative reduction at the electrode of the two imidazolium moieties. The cathodic process was confirmed using the co-electrogenerated hydrogen to reduce 2,2,2- trifluoroacetophenone to the corresponding alcohol.

Details

Language :
English
Database :
OpenAIRE
Accession number :
edsair.doi.dedup.....fa7d94090aaff4698da10220ce428f66