Crystal structure and vibrational spectra of melaminium arsenate

The crystals of the new melaminium arsenate (MAS) [C3H7N6+⋅H2AsO4−] were obtained by the slow evaporation of an aqueous solution at room temperature. Single crystal X-ray diffraction analysis reveals that the crystal belongs to triclinic system with centro symmetric space group P−1. The crystals are built up from single protonated melaminium residues and single dissociated arsenate H2AsO4− anions. The protonated melaminium ring is almost planar. A combination of ionic and donor–acceptor hydrogen-bond interactions linking together the melaminium and arsenate residues forms a three-dimensional network. Vibrational spectroscopic analysis is reported on the basis of FT-IR and FT-Raman spectra recorded at room temperature. Hydrogen bonded network present in the crystal gives notable vibrational effect. DSC has also been performed for the crystal shows no phase transition in the studied temperature range (113–293 K).