A Cationic N‑Heterocyclic Carbene Containing an Ammonium Moiety
收藏NIAID Data Ecosystem2026-03-10 收录
下载链接：
https://figshare.com/articles/dataset/A_Cationic_N_Heterocyclic_Carbene_Containing_an_Ammonium_Moiety/4711372
下载链接
链接失效反馈官方服务：
资源简介：
The dicationic 4-ammonio-substituted
imidazolium salt (2·H)(OTf)2 is readily
obtained from its 4-amino-substituted
imidazolium precursor (1·H)(OTf) by methylation
of the exocyclic nitrogen. The cationic NHC (2)(OTf)
is generated in situ by deprotonation of (2·H)(OTf)2 with 1 equiv of potassium bis(trimethylsilyl)amide and is
trapped with sulfur or selenium. The direct linkage of the cationic
ammonium moiety to the carbenic heterocycle through a σ bond
has a profound effect on the electronic properties of the NHC by significantly
decreasing its σ-donor ability and, to a lesser extent, increasing
its π-acidity. These features make the 4-ammonio-substituted
NHC 2+ an overall weak electron donor. To
evaluate the coordination abilities of carbene 2+, several transition-metal complexes supported by this ligand
have been prepared, including the cationic rhodium(I) complexes [RhCl(cod)(2)](OTf) and [RhCl(CO)2(2)](OTf),
the cationic palladium(II) complexes [PdCl(η3-allyl)(2)](OTf) and [PdCl2(CH3CN)(2)](OTf), the zwitterionic palladium(II) complex [PdCl3(2)], and the tricationic silver(I) complex [Ag(2)2](OTf)3.
创建时间：
2017-03-01
