Sarcosine sarcosinium tetrafluoroborate and sarcosine sarcosinium perchlorate: Synthesis, structure and vibrational spectra

Crystals of the salts of sarcosine sarcosinium tetrafluoroborate and sarcosine sarcosinium perchlorate have been obtained from synthesis out of aqueous solutions. By means of single crystal XRD and vibrational spectroscopy (ATR FTIR and Raman), the crystal and molecular structures were determined and analyzed. Both species are isotypic and crystallize in the orthorhombic space group P212121, with one dimeric (Sar⋯Sar+) cation and one tetrafluoroborate or perchlorate anion within the asymmetric unit. The O⋯O distances in the dimeric cations are equal to 2.506(3) and 2.527(4) Å, respectively. Apart from the strong OH⋯O bond in the dimeric cation, the crystal structures are characterized by NH⋯O and NH⋯F hydrogen bonds that connect the building units. Spectra of sarcosinium tetrafluoroborate and sarcosinium perchlorate are shown for comparison.