Elsevier

Solid State Sciences

Volume 14, Issue 10, October 2012, Pages 1503-1511
Solid State Sciences

Three organically templated magnesium sulfates: Chemical preparation, hydrogen-bonded structures and thermal behavior

https://doi.org/10.1016/j.solidstatesciences.2012.08.027Get rights and content

Abstract

Three new organically templated magnesium sulfates using ethylenediamine, dabco and piperazine have been synthesized by the slow evaporation method and structurally characterized by single-crystal X-ray diffraction. The chemical purity of the products and the presence of the different entities building the compounds were tested by the EDAX measurements, chemical analysis of the elements and the IR spectroscopy. Compound (I), (C2H10N2)[Mg(SO4)2(H2O)4], crystallizes in the triclinic system, space group P −1, while both hybrid materials (C4H12N2)[Mg(H2O)6](SO4)2 (II) and (C6H14N2)[Mg(H2O)6](SO4)2 (III) adopt another structure type and they crystallize in the monoclinic system, space group C2/c. The three supramolecular compounds are built from anions and cations linked together through a 3-D hydrogen bond network. The thermal decomposition of precursors, studied by thermogravimetric analysis (TG) and temperature-dependent X-ray diffraction (TDXD), show successive intermediate hydrates and crystalline anhydrous compounds upon dehydration.

Highlights

► 3 Organically templated magnesium sulfates were synthesized by the slow evaporation method. ► Compound (I) crystallizes in P −1 space group while the two other crystallize in C2/c. ► The thermal decomposition depends on the crystal structure type and the used amine.

Introduction

Organic–inorganic hybrid materials are the subject of major interest, allowing to combine some properties of an inorganic material (or a molecule), and these of an organic molecule (or a polymer). This symbiosis between two worlds of chemistry too long regarded as opposites can also lead to completely new properties, and opens a wide field of investigations for the chemist. The applications of these “new” materials cover diverse areas as the properties of strength, optics, ferroelectricity and ferroelasticity, electronics and ionic solid… Indeed, the crystal engineering of supramolecular compounds is known to favor electric and magnetic properties (see, for example [1], and refs therein). On the other hand, the compounds with hydrogen-bonded structures can leads to interesting ONL properties [2], [3], [4], [5]. Recently, we reported some new organic–inorganic hybrid solids composed of 3d transition metal, sulfate groups and protonated diamine [6], [7], [8], [9], [10], [11], [12], [13], [14], [15]. In this work, we change the transition metals by an alkaline earth metal, Mg, in order to find new structure type and interesting properties due to the difference between the electronic configurations. In the field of our investigations in the organic–inorganic hybrid materials, we report here the chemical preparation, the thermal behavior and the crystallographic characterization of three magnesium sulfates templated by ethylenediamine (I), piperazine (II) and 1,4-diazabicyclo[2.2.2]octane (III).

Section snippets

Chemical preparation

Single crystals of the three compounds were grown as follows: 1 mmol of the magnesium sulfate heptahydrate MgSO4·7H2O, 1 mmol of the amine, ethylenediamine (C2H8N2), piperazine hexahydrate (C4H10N2)·6H2O and 1.4-diazabicyclo[2.2.2]octane (abbreviated dabco) (C6H12N2) for compounds (I), (II) and (III) respectively, and 1 mmol of sulfuric acid H2SO4 were mixed together in a minimum amount of distilled water. The clear solutions were stirred for 15 min and allowed to stand at room temperature.

Crystal structures

The crystal structure of ethylenediammonium tetraaquadisulfatomagnesate(II), [NH3(CH2)2NH3][Mg(SO4)2(H2O)4], (I), consists of [Mg(SO4)2(H2O)4]2− anions, that are built from octahedral Mg(H2O)4O2 and SO4 tetrahedral units linked by corner sharing, and of ethylenediammonium cations linked to the anions via N–H⋯O hydrogen bonds. The asymmetric unit contains only one half of the compound being the other half related to the first one by the inversion center. The crystal structure presents alternate

Concluding remarks

In summary, the synthesis, structure and thermal behavior of three inorganic–organic hybrid magnesium sulfates has been accomplished. The present studies show that the change of the amine, which plays the role of directing agent in this family of hybrid materials, leads to different structure types and influences the thermal decomposition of precursors. Indeed, the use of aliphatic diamine, ethylenediamine, gives a centrosymmetric compound crystallizing in P −1 space group. While the two other

Acknowledgments

Grateful thanks are expressed to Dr. T. Roisnel (Centre de Diffractométrie X, Université de Rennes I) for the assistance in single-crystal X-ray diffraction data collection.

References (29)

  • W. Rekik et al.

    Inorg. Chim. Acta

    (2006)
  • H. Naïli et al.

    Polyhedron

    (2006)
  • W. Rekik et al.

    J. Organomet. Chem.

    (2006)
  • S. Yahyaoui et al.

    J. Solid State Chem.

    (2007)
  • W. Rekik et al.

    Mater. Res. Bull.

    (2008)
  • W. Rekik et al.

    Solid State Sci.

    (2009)
  • M.-C. Daniel et al.

    Chem. Rev.

    (2004)
  • P. Dastidar et al.

    J. Chem. Soc., Perkin Trans. 2

    (1993)
  • S. Bhattacharya et al.

    Chem. Mater.

    (1994)
  • R. Kadirvelraj et al.

    Chem. Mater.

    (1996)
  • R. Kadirvelraj et al.

    J. Incl. Phenom. Mol. Recognit. Chem.

    (1998)
  • W. Rekik et al.

    Acta Crystallogr.

    (2005)
  • W. Rekik et al.

    J. Chem. Crystallogr.

    (2007)
  • W. Rekik et al.

    Acta Crystallogr.

    (2009)
  • Cited by (11)

    • Zn<sup>2+</sup> and Cu<sup>2+</sup> doping of one-dimensional lead-free hybrid perovskite ABX<inf>3</inf> for white light emission and green solar cell applications

      2022, Materials Research Bulletin
      Citation Excerpt :

      Nowadays, hybrid molecular crystals based on metal halides have received increasing attention for their interesting biological, opto-electronic, luminescence and magnetic properties [1–10].

    • A mononuclear Co(II) complex: Crystal structure, thermal behavior, optical properties and biological activities

      2021, Journal of Molecular Structure
      Citation Excerpt :

      The positive control used is ascorbic acid; its absorbance was measured under the same conditions as the samples. An increase in absorbance corresponds to an increase in the reducing power of the tested extract [28]. Scavenging of superoxide radical (NBT test)

    • Synthesis, structural characterization, IR- and Raman spectroscopy, magnetic properties of new organically templated metal sulfates with 4-aminopyridinium

      2016, Journal of Molecular Structure
      Citation Excerpt :

      They include some otms with open-framework structure, which are reported to possess interesting ferroelastic and ferroelectric properties [3,8,9]. Much research has been done on the synthesis of transition and alkaline earth metal based otms with copper [4,6], cobalt [1,10], magnesium [11,12], manganese [13], cadmium [14,15], iron(II) [2,16], zinc [17], nickel [18] and aluminium [3]. The synthesis of organically templated materials often involves the employment of hydrothermal or solvothermal conditions in the presence of protonated organic amines that play the role of structure directing agents or templates.

    View all citing articles on Scopus
    View full text