Type structure, which is composed of organic diammonium, triiodide and hexaiodobismuthate, varies according to different structures of incorporated cations

Abstract

Type structure of (H₃N–R–NH₃)₂I₃BiI₆, which consists of sheets of organic entities together with triiodide anions separated by layers of BiI₆ octahedra, is defined by triiodide, hexaiodobismuthate, and organic diammonium. The prototype structure of (H₃N(CH₂)₂SS(CH₂)₂NH₃)₂I₃BiI₆ (1) can accommodate various changes according to the nature of the organic group, such as conformation, length or size. In (H₃N(CH₂)₂SS(CH₂)₂NH₃)₂I₃BiI₆·0.5H₂O (2), acentric symmetry resulted from the lattice water molecules render the SHG property. Whereas in (H₃N(CH₂)₄NH₃)₂(I₃)_0.5(I(H₂O)₂)_0.5 BiI₆ (3), water molecules are incorporated in the main framework by substituting two iodine atoms of I₃⁻ anion, in the structure of (H₃NCH₂(C₆H₁₀)CO₂H)₄(I₃)₂BiI₆ H₃O (4), pairs of linear triiodide entities [I₃⋯I₃]²⁻ (d(I₃⁻⋯I₃⁻) = 3.77(1) Å) are observed, owing to the super-long diammonium cations of two trans-4-methylammonium cyclohexane carboxylic acid linked together via hydrogen bonding between carboxylate groups.