0000000000528253
AUTHOR
Valeria Agrigento
Molecular association in water-isomeric pentanol mixtures at 25�C
The results of static dielectric constant and viscosity measurements on solutions of water (concentration range 0 to 0.3 mole fraction) in 2-pentanol, 3-pentanol, 2-methyl-1-butanol, 3-methyl-1-butanol, and 2-methyl-2-butanol together with previous results for solutions of water in n-pentanol are discussed in terms of the information that they provide on the nature and the extent of molecular association in these solutions. We conclude that in most systems this association leads to the formation of tetrahedral complexes such as H2O(ROH)4. Evidences of the correlation of water-alcohol interactions with molecular parameters (position of OH group, steric hindrance of alkyl chain) of alcohols a…
Viscosity studies of solutions of water inn-aliphatic alcohols at various temperatures
Viscosity measurements have been made at 25°C on solutions of water inn-propanol, and at 15, 25, 35, and 45°C on solutions of water inn-butanol,n-pentanol, andn-hexanol over the respective solubility ranges. For most of the systems, water decreases the viscosity of the dry alcohols, while for the lower members of the series literature data report an increase in viscosity on addition of water. These results are rationalized in terms of two kinds of interaction between water molecules and alcohols: participation of water molecules in chain formation for the lower alcohols and formation of water-centered complexes for butanol and higher alcohols.
Static dielectric constant, viscosity, and structure of pure isomeric pentanols
Static dielectric constants, viscosities, densitites and refractive indices of 2-pentanol, 3-pentanol, 2-methyl-1-butanol, 3-methyl-1-butanol and 2-methyl-2-butanol were measured at 15, 25, 35 and 45°C. These results together with the previous data on n-pentanol have been analyzed in terms of the Kirkwood correlation factor g k and of the energy of activiation for viscous flow. With the exception of 2-methyl-2-butanol, g k was found to be greater than unity. These results show that the monomeric units of isomeric pentanols interact by means of hydrogen bonding to form dynamic structures essentially of two types: linear chains where co-association raises the total polarizability and cyclic d…