Crystal structure and Hirshfeld surface analysis of the salt 2-iodo-ethyl-ammonium iodide - a possible side product upon synthesis of hybrid perovskites.

The title organic-inorganic hybrid salt, C2H7IN+·I-, is isotypic with its bromine analog, C2H7BrN+·Br- [Semenikhin et al. (2024 ▸). Acta Cryst. E80, 738-741]. Its asymmetric unit consists of one 2-iodo-ethyl-ammonium cation and one iodide anion. The NH3 + group of the organic cation forms weak hydrogen bonds with four neighboring iodide anions, leading to the formation of supra-molecular layers propagating parallel to the bc plane. Hirshfeld surface analysis reveals that the most important contribution to the crystal packing is from N-H⋯I inter-actions (63.8%). The crystal under investigation was twinned by a 180° rotation around [001].