Crystal and Electronic Structure of Stable Nitrenium Ions. A Comparison with Structurally Related Carbenes

The isolation of bis-amino-substituted carbenes of the Arduengo
(3a) and Wanzlick type 4a has
prompted
us to look for stable nitrenium ions of the related structural type
3d+ and
4d+. Thus
5+I-
(6+I-)
and
18+ClO4-
were isolated and structurally characterized by X-ray crystallography.
Theoretical studies give insight into the different
(electronic) structures and stabilities of
3a,d+,
4a,d+, and of related
compounds.