Influence of hydroxyl group position and temperature on thermophysical properties of tetraalkylammonium hydroxide ionic liquids with alcohols.
In this work, we have explored the thermophysical properties of tetraalkylammonium hydroxide ionic liquids (ILs) such as tetrapropylammonium hydroxide (TPAH) and tetrabutylammonium hydroxide (TBAH) with isomers of butanol (1-butanol, 2-butanol and 2-methyl-2-propanol) within the temperature range 293.15-313.15 K, with interval of 5 K and over the varied concentration range of ILs. The molecular interactions between ILs and butanol isomers are essential for understanding the function of ILs in related measures and excess functions are sensitive probe for the molecular interactions. Therefore, we calculated the excess molar volume (V(E) ) and the deviation in isentropic compressibility (Δκs ) using the experimental values such as densities (ρ) and ultrasonic sound velocities (u) that are measured over the whole compositions range at five different temperatures (293.15, 298.15, 303.15, 308.15 and 313.15 K) and atmospheric pressure. These excess functions were adequately correlated by using the Redlich-Kister polynomial equation. It was observed that for all studied systems, the V(E) and Δκs values are negative for the whole composition range at 293.15 K. And, the excess function follows the sequence: 2-butanol>1-butanol>2-methyl-2-propanol, which reveals that (primary or secondary or tertiary) position of hydroxyl group influence the magnitude of interactions with ILs. The negative values of excess functions are contributions from the ion-dipole interaction, hydrogen bonding and packing efficiency between the ILs and butanol isomers. Hence, the position of hydroxyl group plays an important role in the interactions with ILs. The hydrogen bonding features between ILs and alcohols were analysed using molecular modelling program by using HyperChem 7.
Plasma Bioscience Research Center/Department of Electrical and Biological Physics, Kwangwoon University, Seoul, Korea.
Pankaj
P
Attri
Plasma Bioscience Research Center/Department of Electrical and Biological Physics, Kwangwoon University, Seoul, Korea.
Ku Youn
KY
Baik
Department of Chemistry, University of Delhi, Delhi, India.
Pannuru
P
Venkatesu
Department of Chemistry, Kwangwoon University, Seoul, Korea.
In Tae
IT
Kim
Plasma Bioscience Research Center/Department of Electrical and Biological Physics, Kwangwoon University, Seoul, Korea.
Eun Ha
EH
Choi
D000440:Butanols / Q000737:chemistry*; D006860:Hydrogen Bonding; D052578:Ionic Liquids / Q000737:chemistry*; D000644:Quaternary Ammonium Compounds / Q000737:chemistry*; D055672:Static Electricity; D013696:Temperature
D000440:Butanols; D052578:Ionic Liquids; D000644:Quaternary Ammonium Compounds; C052377:tetrapropylammonium; C009405:tetrabutylammonium