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Jo-2015-008303 Micelle Formation in Liquid Ammonia

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Jo-2015-008303 Micelle Formation in Liquid Ammonia Supporting Information The Journal of Organic Chemistry Manuscript ID: jo-2015-008303 Micelle Formation in Liquid Ammonia Joseph M. Griffin, John H. Atherton and Michael I. Page* IPOS, The Page Laboratories, Department of Chemical and Biological Sciences, The University of Huddersfield, Queensgate, Huddersfield, HD1 3DH, United Kingdom Contents Page 1. Ostwald’s dilution law for weak electrolytes 2 2. Kohlrausch’s law for strong electrolytes 4 3. Observed pseudo-first-order rate constants for the ammonolysis of propargyl benzoate as a function of perfluorononanamide concentration 6 1 1. Ostwald’s dilution law for weak electrolytes: Attempts were made to fit the liquid ammonia data to Ostwald’s dilution law: 1 1 ΛΛc = ∘ + ∘ ͦ ΛΛ ΛΛ ͅΏ(ΛΛ) Where: ͦ ͯͥ ΛΛ = Molar conductivity (Sm mol ) ∘ ͦ ͯͥ ΛΛ = Molar conductivity at infinite dilution (Sm mol ) ͅΏ = Acid dissociation constant c = Concentration of electrolyte (M) In water a plot cΛm against 1/Λm gives a straight line for a weak electrolyte such as acetic acid: 1.0E-04 8.0E-05 -3 6.0E-05 dm 2 Sm 4.0E-05 m Λ c 2.0E-05 0.0E+00 0 1000 2000 3000 1/Λ (mol S -1 m-2) m 2 But for liquid ammonia, this relationship is not observed for a simple salt, NH 4Cl, and ionic surfactants: NH 4Cl in liquid ammonia: 5.0E-04 4.0E-04 -3 3.0E-04 dm 2 Sm m m 2.0E-04 Λ c 1.0E-04 0.0E+00 0 50 100 150 200 250 1/Λ (mol S -1 m-2) m Perfluorooctanoic acid in liquid ammonia: 3.0E-04 2.5E-04 -3 2.0E-04 dm 2 1.5E-04 Sm m m Λ c 1.0E-04 5.0E-05 0.0E+00 0 20 40 60 80 100 120 140 -1 -2 1/Λ m (mol S m ) 3 2. Kohlrausch’s law for strong electrolytes: Under the assumption that the ionic species in liquid ammonia should behave as strong electrolytes, Kohlrausch’s law unifies the conductance of such species, according to: ∘ ͥ⁄ ͦ Λ( = Λ( − ĕ͗ Where: ͦ ͯͥ ΛΛ = Molar conductivity (Sm mol ) ∘ ͦ ͯͥ ΛΛ = Molar conductivity at infinite dilution (Sm mol ) ĕ = An empirical constant specific to the salt’s stoichiometry c = Concentration of electrolyte (M) In water, a plot of Λ m against √c for solutions of strong electrolytes g ives a linear relationship. Below is an example for NH 4Cl in water : 0.012 0.01 ) -1 0.008 mol 2 0.006 (Sm m Λ 0.004 0.002 0 0 0.1 0.2 0.3 0.4 0.5 √c (M ½) 4 For liquid ammonia, this relationship is not observed for a simple salt, NH 4Cl, and ionic surfactants: NH 4Cl in liquid ammonia: 0.02 0.016 ) -1 0.012 mol 2 0.008 (Sm m Λ 0.004 0 0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 √c (M ½) Perfluorooctanoic acid in liquid ammonia: 0.025 0.02 ) -1 0.015 mol 2 (Sm 0.01 m Λ 0.005 0 0 0.05 0.1 0.15 0.2 √c (M ½) 5 3. Observed pseudo-first-order rate constants for the ammonolysis of propargyl benzoate as a function of perfluorononanamide concentration The observed pseudo-first-order rate constant for the ammonolysis of propargyl benzoate increases in the presence of perfluorononanamide. Over a range of perfluorononanamide concentrations, the rate increase coincides with concentrations around the cmc obtained from the NMR studies. 16.0 14.0 12.0 -5 10.0 x10 -1 8.0 /s obs 6.0 k 4.0 2.0 0.0 0 20 40 60 80 100 Concentration of perfluorononanamide M Figure Observed pseudo first-order rate constant for the ammonolysis of propargyl benzoate as a function of perfluorononanamide concentration in liquid ammonia at 25 °C. 6 .
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