6533b873fe1ef96bd12d4bfb

RESEARCH PRODUCT

Structural characterization, thermal, dielectric, vibrational properties and molecular dynamics of (C5H5NH)3BiCl6

Grażyna BatorJakub BaranJ. TarasiewiczJacek ZaleskiRyszard JakubasWojciech Medycki

subject

PermittivityPhase transitionOrganic ChemistryAnalytical chemistryInfrared spectroscopyDielectricTriclinic crystal systemAnalytical ChemistryInorganic ChemistryCrystallographychemistry.chemical_compoundDifferential scanning calorimetrychemistryPhase (matter)PyridiniumSpectroscopy

description

Abstract (C5H5NH)3BiCl6 crystallizes at room temperature in the triclinic space group P 1 ¯ . The crystal is built up of the separated BiCl 6 3 - octahedral anions and pyridinium cations. Differential scanning calorimetry (DSC) and dilatometric measurements disclose structural phase transition of first-order type at 265/302 K (cooling/heating). The dielectric investigations reveal a step-wise change of the electric permittivity at Tc characteristic of the crystals with the high-temperature plastic-like phase. Temperature-dependent infrared spectra for polycrystalline samples have been taken between 20 and 306 K to clarify the cation dynamics contribution to the mechanism of the phase transition. The modes assigned to the deformation vibration of the NH+ group in the pyridinium ring appear to be the most sensitive to the phase transition. The possible molecular motions of the C5H5NH+ cations are studied by the proton magnetic resonance (1H NMR).

yearjournalcountryeditionlanguage
2009-08-01Journal of Molecular Structure
https://doi.org/10.1016/j.molstruc.2009.05.034