Thermal Analysis and Raman Spectra of Different Phases of the Ionic Liquid Butyltrimethylammonium Bis(trifluoromethylsulfonyl)imide
Contribuinte(s) |
UNIVERSIDADE DE SÃO PAULO |
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Data(s) |
03/10/2013
03/10/2013
2012
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Resumo |
The ionic liquid butyltrimethylammonium bis(trifluoromethylsulfonyl)imide, [C4C1C1C1N][Tf2N], is a glass-forming liquid that exhibits partial crystallization depending on the cooling rate. Differential scanning calorimetry (DSC) indicates crystallization at T-c = 227 K, melting at T-m = 258 K, glass transition at T-g similar to 191 K, and also cold crystallization at T-cc similar to 219 K. Raman spectroscopy shows that the crystalline structure obtained by slow cooling is formed with [Tf2N](-) in cisoid conformation, whereas [Tf2N](-) in transoid conformation results from fast cooling. No preferred conformation of the butyl chain of the [C4C1C1C1N](+) cation is favored by slow or fast cooling of [C4C1C1C1N][Tf2N]. Low-frequency Raman spectroscopy shows that crystalline domains developing in the supercooled liquid result in a glacial state made of a mixture of crystallites and amorphous phase. However, these crystalline structures obtained by slow cooling or cold crystallization are not the same because anion-cation interactions promote local structures with distinct conformations of the [Tf2N](-) anion. FAPESP FAPESP CNPq CNPq |
Identificador |
JOURNAL OF PHYSICAL CHEMISTRY B, WASHINGTON, v. 116, n. 30, pp. 9238-9245, AUG 2, 2012 1520-6106 http://www.producao.usp.br/handle/BDPI/33979 10.1021/jp3051824 |
Idioma(s) |
eng |
Publicador |
AMER CHEMICAL SOC WASHINGTON |
Relação |
Journal of Physical Chemistry B |
Direitos |
closedAccess Copyright AMER CHEMICAL SOC |
Palavras-Chave | #GLASS-FORMING LIQUIDS #TRIPHENYL PHOSPHITE #SUPERCOOLED LIQUIDS #1-BUTYL-3-METHYLIMIDAZOLIUM BROMIDE #GLACIAL STATE #POLYAMORPHISM SITUATION #DIELECTRIC-RELAXATION #LIGHT-SCATTERING #AB-INITIO #DYNAMICS #CHEMISTRY, PHYSICAL |
Tipo |
article original article publishedVersion |