Layered structure of a supramolecular hybrid sulfate salts: Thermal stability and magnetic behavior

• Published in: Inorganica Chimica Acta Vol. 434; pp. 209 - 214
• Main Authors: Kammoun, Omar, Naïli, Houcine, Rekik, Walid, Bataille, Thierry
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.08.2015; Elsevier
• Subjects: Chemical Sciences; Hybrid material; Lamellar structure; Material chemistry; Sulfate salt; Supramolecular; Lamellar structure; Supramolecular; Sulfate salt; Hybrid material
• ISSN: 0020-1693; 1873-3255; 0020-1693
• DOI: 10.1016/j.ica.2015.05.031

The templating effect of 2-methylimidazolium amine in hybrid sulfate salts of transition metal known as supramolecular materials provided a layered structure type with an interlayer distance of 11.6Å. [Display omitted] •A supramolecular hybrid sulfate salts templated by 2-methylimidazolium amine.•The crystal structure show a lamellar stack with an interlayer distance of 11.6Å.•Thermal dehydration showed an important thermal stability.•The paramagnetic behavior of this class of hybrid materials was highlighted. The incorporation of the aromatic diamine 2-methylimidazole as template in the synthesis of hybrid sulfate salts with transition metal was effected by the slow evaporation method. The resulting structure presents a lamellar character with a supramolecular network, which is uncommon in the family of sulfates and their derivates. The three synthesized compound with the general formula (C4H7N2)2[MII(H2O)6](SO4)2·2H2O (MII=Zn, Co and Mn) crystallize in the monoclinic symmetry, space group P21/c. According to the design shape of the protonated amine and its bonding relations between the supramolecular inorganic layers, building from hydrogen bond only, the interlamellar distance reached 11.6Å. The π-stacking between aromatic moieties of amines have a relevant role in stabilizing the lamellar structure. The thermal study with in situ powder X-ray diffraction and thermogravimetry of the synthesized compounds showed that the dehydration stage of precursors lead to the formation of an anhydrous crystalline phase with a good thermal stability. Beyond this and under the decomposition stage, Co and Zn compound become amorphous whereas the Mn-based compound showed successive crystalline phases. The magnetic measurements performed for the cobalt based compound indicate a low interaction exchange within the material in agreement with a typical paramagnetic behavior.