Glycine–methanesulfonic acid (1:1) and glycine–p-toluenesulfonic acid (1:1) crystals: Comparison of structures, hydrogen bonds, and vibrations

The crystal structures of glycine–methanesulfonic acid (1:1) and glycine–p-toluenesulfonic acid (1:1) have been investigated by X-ray diffraction at 293 K. They belong to centrosymmetric: (i) P21/n space group of monoclinic system and (ii) Pbca space group of orthorhombic system, respectively. Both crystals consist of glycinium–sulfonate dimers (methane- or p-toluenesulfonate, respectively) with medium-strong and very similar O–H⋯O hydrogen bonds. N–H⋯O bonds connect glycinium–sulfonate dimers into infinite chains. Both sulfonic acids reveal very similar acidic properties. In glycine–p-toluenesulfonic acid (1:1) crystal very weak, C–H⋯π improper hydrogen bonds are formed. Vibrational spectra of the crystals are related to their structures.