The studies of viscosity behaviour in aqueous 18-crown-6 solutions at 25°C

Thermodynamics of complexation of aqueous 18-crown-6 with potassium ion: apparent molar volumes and apparent molar heat capacities of aqueous 18-crown-6 and of the (18-crown-6+potassium chloride) complex at temperatures (278.15 to 393.15) K, at molalities (0.02 to 0.3) mol·kg−1, and at the pressure 0.35 MPa

“…Our V / results for 18C6(aq) agree well with literature values [24][25][26][27][28][29][30][31][32][33]. We give in table 5 our calculated V 2 ¼ ð223:16 AE 0:3Þ cm 3 Á mol À1 (= V / at m* = 0) at T* = 298.15 along with V 2 from the literature [24,[26][27][28][29][30][31][32][33]. The average of the literature values is (223.4 ± 0.8) cm 3 AE mol À1 , which differs from our value by 0.2 cm 3 AE mol À1 .…”

Evidences for Inclusion and Encapsulation of an Ionic liquid with β-CD and 18-C-6 in Aqueous Environments by Physicochemical Investigation

“…Complex formation connecting Crown and chosen pyrrolidinium ion involves different possible modes of interactions . The most important one is hydrogen bonding interaction among oxygen atom of 18-C-6 (O-crown) along with acidic N + protons in pyrrolidinium ion [(N + ) pyrrolidinium] for a (N + ) pyrrolidinium·····O-crown interaction .…”

“…Apart from Vander waals-bonding, induced dipole–dipole interaction amid pyrrolidinium ion and O-crown having δ charge possibly will also contribute to the overall stability of the complex formation . Conversely, this induced dipole–dipole interaction is expected to be weaker as compared with Vander waals bonding interaction as discussed . The stability constants (log K b ′) in favor of 1:1 complexation were calculated in aqueous solution by conductivity study and are presented in (Table a).…”

Studies of Osmotic and Activity Coefficients in Aqueous and CCl4 Solutions of 18-Crown-6 at 25 °C

“…The simplest potential function regards the molecules as rigid spheres. For two hard spheres of diameters R 1 and R 2 , The self-diffusion coefficient 8 study and viscosity measurement 18,19 of aqueous 18C6 solutions at 25°C have shown that the radius of 18C6 in aqueous solutions is 0.5 nm. The water molecule can be considered to be a sphere of diameter 0.304 nm (although one may use the diameter of water as 0.276 nm, however we retained the value equal to 0.304 nm as the comparison of the data for other solutes can be made).…”