2-Aminopyridin-1-ium triiodide

Abstract

The asymmetric unit of the title compound, C5H7N2 +.I3 −, consists of one 2-amino­pyridin-1-ium cation (apyH+) and one triiodide anion, both located in general postions. The apyH+ cation is planar within the experimental uncertainties. The short N—C distance [1.328 (5) Å] of the exocyclic NH2 group is typical for the imino-form of protonated 2-amino­pyridines. Consequently, the bond lengths within the six-membered ring vary significantly. The geometric parameters of the triiodide anion are in the typical range, with bond lengths of 2.8966 (3) and 2.9389 (3) Å and a bond angle of 176.02 (1)°. In the crystal, N—H ⋯ I hydrogen bonds connect adjacent ions into screwed chains along the b-axis direction. These chains are twisted pairwise into rectangular rods. The pyridinium moieties of neighbouring rods are arranged parallel to each other with a plane-to-plane distance of 3.423 (5) Å.

The twinned crystal structure of bis((4-aminopyridin-1-ium) iodide triiodide, C20H28I8N8

“…Especially the semi-flexible a,w-diazaniumalkane cationsassistedthe synthesisofaseries of new polyiodides [5,1 5-18]. This contribution is part of our general interest in the hydrogen bonding topologies of aminopyridinium salts [19] and of our attempts to synthesise polyiodides using simple N-heterocyclic cations [20][21][22]. The asymmetric unit of the title structure consists of four crystallographically independent 4-aminopyridin-1-ium cations, two iodide and two triiodide anions.…”

Halogen and hydrogen bonding in the layered crystal structure of 2-iodoanilinium triiodide, C6H7I4N

“…We have already shown that heterocyclic cations like pyridinium derivatives [22,23] or naturally occurring bases like caffeine [24] are excellent educts for the synthesis of polyiodide containing salts. In particular, there is profound interest in the competition between hydrogen and halogen bonding in haloanilinium halogenides [25,26].…”

Crystal structure of 4-nitro-thiophene-2-carboxylic acid, a structure with a Z′ = 4, C5H3NO4S

“…Stacking of planar molecules with orientational deviations to ll the needs of packing are known well known [10].…”