ISSN:
1089-7690
Source:
AIP Digital Archive
Topics:
Physics
,
Chemistry and Pharmacology
Notes:
The Raman spectrum as well as conductivity and differential-thermal-analysis (DTA) thermogram of tetramethylammonium hydroxide pentahydrate was observed at various temperatures in order to investigate molecular motion in relation to conductivity and a phase transition. It was clarified that different stepwise protonation processes become effective for relaxation in the O–H stretching of hydroxide ions as temperature is increased. The activation energy was 6.1 and 16.0 kJ/mol in 130≤T〈210 and 210≤T≤250 K, respectively, whereas the activation energy in conductivity was 41.1 kJ/mol below 250 K. This discrepancy was discussed according to a reorientational motion of water molecules. The Raman band shape of the NM4 asymmetric stretching of tetramethylammonium ions was analyzed on the basis of the reorientational motion about the C3 and C2 axes on the ion, and the activation energies were 8.7 kJ/mol (about the C3 axis) and 14.5 kJ/mol (about the C2 axis).
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.461254
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