Available online www.jocpr.com Journal of Chemical and Pharmaceutical Research, 2015, 7(12):822-829 Research Article ISSN : 0975-7384 CODEN(USA) : JCPRC5 822 Synthesis, structural study, IR spectroscopic investigation and thermal behaviour of bis(3-ammoniopropyl) ammonium sulfate monohydrate Hasna Ettis 1,2 , Melek Hajji 1 and Taha Guerfel 1,2* 1 Laboratoire d’Electrochimie, Matériaux et Environnement, Université de Kairouan, Kairouan, Tunisia 2 Institut Préparatoire aux Etudes d’Ingénieurs de Kairouan, Université de Kairouan, Kairouan, Tunisia _____________________________________________________________________________________________ ABSTRACT Crystals of bis(3-ammoniopropyl)ammonium sulfate monohydrate: (C 6 H 20 N 3 )SO 4 HSO 4 .H 2 O were prepared and grown at room temperature by slow evaporation method. Crystal structure, IR spectroscopy and thermal behaviour were investigated. The structure of this new organic sulfate was determined by single crystal X-ray diffraction technique. The title compound crystallizes in the orthorhombic space group Pbcn. It is composed of dimers resulting from the association of SO 4 2- and HSO 4 - anions with water molecules. The inorganic arrangement shows cavities where the organic molecules are located to create a three-dimensional framework. Keywords: Organic sulfate; Crystal structure; Thermal analysis; IR investigation. _____________________________________________________________________________________________ INTRODUCTION The structural study of several atomic arrangements of organic sulfates has shown the important role of the sulfate anion in the construction of hydrogen bonds networks. In HSO 4 - or SO 4 2- anions, the oxygen atoms, as acceptors, provide a strong contribution to the construction of channels or layers which capable to encapsulating polarisable organic molecules.Such a crystal engineering route combines the cohesion and flexibility of anionic inorganic lattices with the enhanced polarizability of organic entities [1]. Beside non-linear optical properties [2], some sulfates exhibit phase transitions, like (C 6 H 18 N 2 )SO 4. H 2 O [3] and (C 4 H 12 N) 2 SO 4 [4]. The present study is part of a systematic investigation of the interaction of various amines with sulphuric acid[5-9]. This study allowed the finding of a new organic sulfate, (C 6 H 20 N 3 ) SO 4. HSO 4 .H 2 O.Chemical preparation; crystal structure, thermal behaviour and IR spectrum of this new compound are discussed. EXPERIMENTAL SECTION Synthesis The synthesis of bis(3-ammonio-propyl)ammonium sulfate monohydrate is made in two steps: First, 400 mLof an aqueous solution of sulfuric acid (10 -1 M) is prepared from the dilution of 2.24mL H 2 SO 4 (96 %, d = 1.84g/cm 3 ). The obtained solution is then neutralized by adding drop wise the bis(3-amino-propyl)amine, under magnetic stirring. Second, the resulting solution is then evaporated at room temperature for several weeks. Other syntheses were made by changing the volumes, the pH, the concentration and the rate of evaporation. In all cases, the evaporation of the solutions led, to prismatic and transparent single crystals suitable for a structural study. The preparation of this compound is reproducible and made according to the reaction: