[Zurück]

B. Lendl:
"STUDY OF ASSOCIATION STATES OF METHANOL AND WATER DISSOLVED IN IONIC LIQUIDS BY FTIR SPECTROSCOPY USING GENERALIZATED 2 DIMENSIONAL CORRELATION SPECTROSCOPY AND MULTIVARIATE CURVE RESOLUTION";
Vortrag: 3rd International Conference on Two Dimensional Correlation Spectroscopy, Delavan, Wisconsin, USA (eingeladen); 12.08.2005 - 14.08.2005.

Binary mixtures of methanol and water in three ionic liquids (IL), 1-ethyl-3-methylimidazolium tetrafluoroborate (emimBF4), 1-butyl-3-methylimidazolium tetrafluoroborate (bmimBF4) and 1-butyl-3-methylimidazolium hexafluorophosphate (bmimPF6) have been studied using Fourier transform Infrared Spectroscopy. A sequential injection system (SIA) allowed the reproducible preparation of different concentration mixtures by automated dilution of gravimetrically prepared mixtures. The region of OH stretching (3800 - 3250 cm-1) has been analyzed using 2 Dimensional Correlation Spectroscopy (2DCoS) and Multivariate Curve Resolution (MCR). Both chemometric techniques give evidence that at low concentrations only methanol and water monomers interacting with the anion of the ionic liquid exist. At higher methanol/water concentrations a second species is observed. The concentration profiles and the pure infrared spectra have been recovered using MCR-ALS. According to the observed spectral features the second species can be assigned to water or methanol dimers. In the most hydrophobic ionic liquid bmimPF6 only one water species could be clearly identified. No evidence was found that bigger water/methanol clusters are formed in these IL in the studied concentration range

http://publik.tuwien.ac.at/files/pub-tch_4953.doc