Crystal structures and vibrational spectra of novel compounds with dimeric glycine glycinium cations

The glycinium compounds glycine glycinium tetrafluoroborate (GlyH·Gly·BF4) (I), glycine glycinium perchlorate (GlyH·Gly·ClO4) (II), glycinium tetrafluoroborate (GlyH·BF4) (III), glycinium perchlorate (GlyH·ClO4) (IV), and glycine glycinium iodide (GlyH·Gly·I) (V) have been synthesized, (I–IV) for the first time. The crystal structures could be determined for (I), (II), and (V), the first two represent novel species and have therefore been characterized by vibrational spectroscopy as well. Compounds (III) and (IV) proved unstable and are characterized by vibrational spectroscopy only. The results of the redetermination of (V) are compared with previously reported data. The crystal structures comprise dimeric cations of the type (GlyH⋯Gly) connected to monovalent anions via hydrogen bonds.