TY - JOUR
T1 - New short aliphatic chain ionic liquids
T2 - Synthesis, physical properties, and catalytic activity in aldol condensations
AU - Cota, I.
AU - Gonzalez-Olmos, R.
AU - Iglesias, M.
AU - Medina, F.
PY - 2007/11/1
Y1 - 2007/11/1
N2 - This paper reports on the synthesis of new short aliphatic chain ionic liquids and the study of the temperature dependence of density, ultrasonic velocities, and ionic conductivity in the range of 278.15 - 338.15 K. Fourier transform infrared spectra establishes their simple ionic salt structure. Because of their polarity, the ionic liquids are able to dissolve polar solvents and inorganic salts, all of them showing high tolerance in hydroxylic media. The observed temperature trend of the studied properties points out the special packing of these ionic liquids, as well as the strong influence of the steric hindrance among linear aliphatic residues enclosed in anions and cations. One of them showed a very high melting temperature. A collection of slightly basic ionic liquids were used to test their catalytic activity in several aldol condensation reactions of some carbonyl compounds. The best conversions and selectivities were obtained using single ionic liquids, with no synergetic effects being observed when different concentrations of mixed ionic liquids were used as catalysts. In any case, the ionic liquid can also easily be recycled from reaction media, suggesting a promising method of process design for this kind of reaction.
AB - This paper reports on the synthesis of new short aliphatic chain ionic liquids and the study of the temperature dependence of density, ultrasonic velocities, and ionic conductivity in the range of 278.15 - 338.15 K. Fourier transform infrared spectra establishes their simple ionic salt structure. Because of their polarity, the ionic liquids are able to dissolve polar solvents and inorganic salts, all of them showing high tolerance in hydroxylic media. The observed temperature trend of the studied properties points out the special packing of these ionic liquids, as well as the strong influence of the steric hindrance among linear aliphatic residues enclosed in anions and cations. One of them showed a very high melting temperature. A collection of slightly basic ionic liquids were used to test their catalytic activity in several aldol condensation reactions of some carbonyl compounds. The best conversions and selectivities were obtained using single ionic liquids, with no synergetic effects being observed when different concentrations of mixed ionic liquids were used as catalysts. In any case, the ionic liquid can also easily be recycled from reaction media, suggesting a promising method of process design for this kind of reaction.
UR - https://www.scopus.com/pages/publications/36048982820
U2 - 10.1021/jp073963u
DO - 10.1021/jp073963u
M3 - Article
AN - SCOPUS:36048982820
SN - 1520-6106
VL - 111
SP - 12468
EP - 12477
JO - Journal of Physical Chemistry B
JF - Journal of Physical Chemistry B
IS - 43
ER -