Vibrational spectroscopic and crystallographic study of the novel guanylurea salts with sulphuric and selenic acids

Abstract The family of known guanylurea(1+) sulphates was extended for two novel triclinic ( space groupP -1) members - bis(guanylurea(1+)) sulphate dihydrate and tetrakis(guanylurea(1+)) bis(hydrogen sulphate) sulphate. Additionally, the monoclinic ( space groupP 2 1 / n ) guanylurea(1+) hydrogen selenatewas also isolated and characterised. Besides of X-ray diffraction study these novel guanylurea chalcogenateswere studied by the methods of vibrational spectroscopy. The study of thermal behaviour of the prepared salts revealed reversible λ-shaped anomaly for tetrakis(guanylurea(1+)) bis(hydrogen sulphate) sulphate at 354 K. This effect was studied in detail by the combination of DSC and temperature-dependent IR and Raman spectroscopies.