Synthesis, crystal structures, phase transition characterization and thermal decomposition of a new dabcodiium hexaaquairon(II) bis(sulfate): (C{sub 6}H{sub 14}N{sub 2})[Fe(H{sub 2}O){sub 6}](SO{sub 4}){sub 2}

Journal Article · Sat Dec 15 00:00:00 EST 2007 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/j.jssc.2007.10.019· OSTI ID:21043788

Yahyaoui, Samia ^[1]; Rekik, Walid ^[1]; Naili, Houcine; Mhiri, Tahar ^[1]; Bataille, Thierry ^[2]

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1. Laboratoire de l'Etat Solide, Departement de Chimie, Faculte des Sciences de Sfax, BP 802, 3018 Sfax (Tunisia)
2. Laboratoire Sciences Chimiques de Rennes (CNRS, UMR 6226), Groupe Materiaux Inorganiques: Chimie Douce et Reactivite, Universite de Rennes 1, Avenue du General Leclerc, 35042 Rennes Cedex (France)

The crystal structures of 1,4-diazabicyclo[2.2.2]octane (dabco)-templated iron sulfate, (C{sub 6}H{sub 14}N{sub 2})[Fe(H{sub 2}O){sub 6}](SO{sub 4}){sub 2}, were determined at room temperature and at -173 deg. C from single-crystal X-ray diffraction. At 20 deg. C, it crystallises in the monoclinic symmetry, centrosymmetric space group P2{sub 1}/n, Z=2, a=7.964(5), b=9.100(5), c=12.065(5) A, {beta}=95.426(5) deg. and V=870.5(8) A{sup 3}. The structure consists of [Fe(H{sub 2}O){sub 6}]{sup 2+} and disordered (C{sub 6}H{sub 14}N{sub 2}){sup 2+} cations and (SO{sub 4}){sup 2-} anions connected together by an extensive three-dimensional H-bond network. The title compound undergoes a reversible phase transition of the first-order at -2.3 deg. C, characterized by DSC, dielectric measurement and optical observations, that suggests a relaxor-ferroelectric behavior. Below the transition temperature, the compound crystallizes in the monoclinic system, non-centrosymmetric space group Cc, with eight times the volume of the ambient phase: a=15.883(3), b=36.409(7), c=13.747(3) A, {beta}=120.2304(8){sup o}, Z=16 and V=6868.7(2) A{sup 3}. The organic moiety is then fully ordered within a supramolecular structure. Thermodiffractometry and thermogravimetric analyses indicate that its decomposition proceeds through three stages giving rise to the iron oxide. - Graphical abstract: The new dabcodiium hexaaquairon(II) bis(sulfate), (C{sub 6}H{sub 14}N{sub 2})[Fe(H{sub 2}O){sub 6}](SO{sub 4}){sub 2}, was prepared and characterized. It exhibits a supramolecular structure and undergoes a reversible order-disorder phase transition at -2.3 deg. C.

• OSTI ID: 21043788
• Journal Information: Journal of Solid State Chemistry, Vol. 180, Issue 12; Other Information: DOI: 10.1016/j.jssc.2007.10.019; PII: S0022-4596(07)00431-8; Copyright (c) 2007 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); ISSN 0022-4596
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
ANIONS
CALORIMETRY
CATIONS
DIELECTRIC PROPERTIES
IRON COMPLEXES
IRON OXIDES
IRON SULFATES
MONOCLINIC LATTICES
MONOCRYSTALS
ORDER-DISORDER TRANSFORMATIONS
PYROLYSIS
SYMMETRY
TEMPERATURE RANGE 0065-0273 K
TEMPERATURE RANGE 0273-0400 K
TRANSITION TEMPERATURE
X-RAY DIFFRACTION