Crystal structure, phase transition, electrical and optical properties of p-hydroxypyridinium iodate [C5H6NO (IO3)]2
| Autor: | Slaheddine Kamoun, Mohamed Amine Ben Abdallah |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
Phase transition
010405 organic chemistry Chemistry Organic Chemistry Analytical chemistry Crystal structure Conductivity 010402 general chemistry 01 natural sciences 0104 chemical sciences Analytical Chemistry Inorganic Chemistry chemistry.chemical_compound Electrical resistivity and conductivity Single crystal Temperature coefficient Spectroscopy Iodate Monoclinic crystal system |
| Zdroj: | Journal of Molecular Structure. 1178:52-61 |
| ISSN: | 0022-2860 |
| DOI: | 10.1016/j.molstruc.2018.10.008 |
| Popis: | The structural investigation of a new hybrid iodate compound [C5H6NO (IO3)]2 denoted as HPI was performed using single crystal and powder X-ray diffraction. The synthesized compound was also characterized using DSC, FT-IR, 13C Mass/NMR, diffuse reflectance (DRS), fluorescence and complex impedance spectroscopy (CIS). The new hybrid iodate salt crystallizes in the monoclinic system and in the acentric space group “Pn”. DSC and VT-XRPD measurements revealed that HPI undergoes a first order phase transition at 383 K showing a discontinuous increase of the molar volume and entropy. The temperature variation of AC and bulk conductivity plots of HPI showed two straight-line regions with a change in slope around 380 K corresponding to the structural phase transition. The bulk resistance, deduced from the thermal variation of Z′ and Z″ in both phases is found to decrease with rise in temperature, suggesting a negative temperature coefficient of resistance (NTCR) behavior of this compound. The electrical σtot (ω, T) conductivity obeyed to the Jonscher's power law and the temperature dependence of the S (T) parameter showed that the electrical conductivity of the HPI compound may be treated using correlated barrier hopping (CBH) model. The hopping of the proton H+ as a charge carrier may take place through the N H⋯O and O H⋯O hydrogen bonds. |
| Databáze: | OpenAIRE |
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