G. Korus et M. Jansen, Crystal structure, phase transition, and potassium ion conductivity of potassium trifluoromethanesulfonate, Z ANORG A C, 627(7), 2001, pp. 1599-1605
Citations number
24
Categorie Soggetti
Inorganic & Nuclear Chemistry
Journal title
ZEITSCHRIFT FUR ANORGANISCHE UND ALLGEMEINE CHEMIE
According to the results of temperature dependent powder diffractometry (Gu
inier-Simon-technique) potassium trifluoromethanesulfonate is dimorphic. Th
e phase transition occurs between -63 degreesC and 45 degreesC. The low-tem
perature modification crystallizes monoclinic with a=10.300(3)Angstrom, b =
6.052(1) Angstrom, c = 14.710(4) Angstrom, beta =111.83(2)degrees (-120 de
greesC) and the room-temperature modification with a=10.679(5) Angstrom, b=
5.963(2)Angstrom, c=14.624(5)Angstrom, beta =111.57(3)degrees, Z=6, P2(1).
According to single crystal structure determination, potassium trifluoromet
hanesulfonate consists of three different potassium-oxygen-coordination pol
yhedra, linked by sulfur atoms of the trifluoromethanesulfonate groups. Thi
s results in a channel structure with all lipophilic trifluoromethane group
s pointing into these channels. By means of DSC, the transition temperature
and enthalpy have been determined to be -33 degreesC and 0.93 +/-0.03 kJ/m
ol, respectively. The enthalpy of melting (237 degreesC) for potassium trif
luoromethanesulfonate is 13.59kJ/mol, the potassium ionic conductivity is 3
.68.10(-6) Scm(-1) at 205 degreesC.