- Tytuł:
- Vibrational Spectroscopic Properties of a $[C(NH_2)_3]_4Cl_2SO_4$ Ferroelectric Crystal - An Experimental and Theoretical Study
- Autorzy:
-
Podsiadła, D.
Czupiński, O.
Dudzic, D.
Czapla, Z. - Powiązania:
- https://bibliotekanauki.pl/articles/1207043.pdf
- Data publikacji:
- 2014-01
- Wydawca:
- Polska Akademia Nauk. Instytut Fizyki PAN
- Tematy:
-
78.30.-j
78.20.Bh
77.80.B- - Opis:
- Tetraguanidinium dichloride-sulphate crystal, $[C(NH_2)_3]_4Cl_2SO_4$, abbreviated as $G_4Cl_2SO_4$ was investigated. The vibrational infrared spectra of powdered $G_4Cl_2SO_4$ crystal in Nujol mull were studied in the wide range of temperature, from 298 K to 377 K. This temperature range contains all the phases in the crystal (named III, II, I on heating, respectively). The temperature changes of wavenumbers, centre of gravity, and intensity of the bands were analyzed to clarify the molecular mechanism of the phase transitions. It was shown that in cooling from 377 K to 313 K the phase II is the same as the room temperature phase. Information about hydrogen bonds was obtained. The time dependence of internal vibrations at 356 K was observed and it was connected with slow transition III → II. For more detailed band assignment Raman spectrum at room temperature, at ferroelectric phase was carried out. Theoretical calculations were made based on density functional theory, with the B3LYP method using 6-311 + G(d,p) basic set. Calculated normal vibrational modes of the molecule, their frequencies and intensities were compared with these recorded in experiment. Theoretical description of the molecule including hydrogen bonds were optimized and the bond parameters were obtained. The Mulliken charges population analysis was performed.
- Źródło:
-
Acta Physica Polonica A; 2014, 125, 1; 115-127
0587-4246
1898-794X - Pojawia się w:
- Acta Physica Polonica A
- Dostawca treści:
- Biblioteka Nauki
Artykuł