L-Tryptophanium iodide and l-tryptophanium l-tryptophan iodide monohydrate

Abstract

The new salts l-tryptophanium iodide (I) and l-tryptophanium l-tryptophan iodide monohydrate (II) have been obtained. The salt (I) crystallizes in the orthorhombic system (space group P212121, Z = 4) and is not isostructural with l-tryptophanium chloride and l-tryptophanium bromide, which have P21 symmetry. Compound (II) is a salt with (l-TrpH···l-Trp) type dimeric cation. It crystallizes in the orthorhombic system (space group P212121, Z = 4) and is isostructural with l-tryptophanium l-tryptophan bromide monohydrate. The dimeric cation in (II) is formed by an O–H⋯O hydrogen bond with an O⋯O distance of 2.482(2) Å. The infrared and Raman spectra of the crystals are studied and discussed.