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

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 P2(1) (Z = 4). L-Alanine center dot center dot center dot L-alaninium dimers are realized via rather short O-H center dot center dot center dot O hydrogen bonds between carboxyl and carboxylate groups with the O center dot center dot center dot O distances equal to 2.421(2), 2.423(2) angstrom in (I), 2.437(10), 2.413(8) angstrom in (II) and 2.421(5), 2.442(5) angstrom 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. (C) 2018 Elsevier B.V. All rights reserved.