L-Alanine halogenides with l-alanine l-alaninium dimeric cation

Abstract

Crystalline salts l-alanine l-alaninium chloride (I), l-alanine l-alaninium bromide (II) and l-alanine l-alaninium iodide (III) were obtained, which have dimeric cations in the structure. The salts crystallize in the monoclinic crystal system with the space group P21 (Z = 4). l-Alanine···l-alaninium dimers are realized via rather short OH⋯O hydrogen bonds between carboxyl and carboxylate groups with the O⋯O distances equal to 2.421(2), 2.423(2) Å in (I), 2.437(10), 2.413(8) Å in (II) and 2.421(5), 2.442(5) Å in (III) at 200 K. The salts (I) and (II) are isotypic, while the salt (III) has different packing so the structure is distinct. The infrared and Raman spectra and the crystal structures of these compounds are discussed. Besides, we obtained for the first time a new simple salt l-alaninium iodide.