6533b860fe1ef96bd12c3bce
RESEARCH PRODUCT
Polar metal–formate frameworks templated with 1,2-diaminoethane–water assemblies showing ferromagnetic and ferroelectric properties
Mirosław MączkaMonika TrzebiatowskaRyszard PoprawskiBartosz ZarychtaAdam PikulPaulina Peksasubject
Materials scienceHydrogen bondGeneral Physics and AstronomyInfrared spectroscopy02 engineering and technology010402 general chemistry021001 nanoscience & nanotechnology01 natural sciencesFerroelectricity0104 chemical sciencesIonPyroelectricitychemistry.chemical_compoundCrystallographychemistryFerromagnetismMoleculeFormatePhysical and Theoretical Chemistry0210 nano-technologydescription
A set of five novel formate frameworks templated with assemblies comprising diprotonated 1,2-diaminoethane (DAE) and a water molecule of the formula: [NH3(CH2)2NH3]M2(HCOO)6·H2O, where M = Mg, Mn, Co, Ni, Zn, has been synthesized. Four compounds crystallize in the polar R3 space group and one in the chiral P6322 space group (Ni-analog) at room temperature. The polyammonium–water assemblies, mutually joined by hydrogen bonds, fill the cavities of the frameworks and are disordered in the three latter compounds. Additional disorder is found in the Ni-sample as the DAE2+–H2O couple is placed in a special position on the 63 screw axis. IR spectroscopy provides evidence of proton dynamic disorder within the assemblies, which turns into a static one at low temperatures. The crystals preserve their arrangement up to approximately 370 K as shown by differential calorimetric measurements and temperature-dependent IR spectroscopy. The ferroelectric nature of a representative of the family, DAEMgF, at room temperature has been confirmed by pyroelectric measurements. It has been found that the spontaneous polarization may be changed by an external electric field. The magnetic studies reveal a weak ferromagnetic behavior within 8.5–35 K for magnetically active ions: Mn, Co, and Ni.
year | journal | country | edition | language |
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2017-06-18 | Physical Chemistry Chemical Physics |