Microcalorimetric Study on the Oscillating System of Two-phase Reaction of Aqueous Acid with Primary Amine in Chloroform

It has been found that the two‐phase reactions of aqueous HCl, HOAc or H₃PO₄ with primary amine N₁₉₂₃ in chloroform are oscillating reactions. Their power‐time curves were measured by the titration microcalorimetric method, and the induction period (t_ta). The first oscillating period (t_p.1) and the second oscillating period (t_p.2) were determined. The apparent activating parameters and the orders of the oscillating systems were calculated and the following relationships were established: for the oscillating system of hydrochloric acid t_in ∞ c^0.147_HCI exp(1.35 × 10³/T), t_p.1 ∞ c^0.241_HCI, exp(4.33 × 10³/T), t_p.2 ∞ c^0.290_HCI exp(5.59 × 10³/T); for the oscillating system of acetic acid, t_in ∞ c^0.883_HOAc exp(2.32 × 10³/T), t_p.1 ∞ c^0.399_BOAc, exp(4.50 × 10³/T), t_p.2 ∞ c^0.301_HOAc exp(5.88 × 10³/T); for the oscillating system of phosphoric acid, t_in ∞ c^1.14 exp(7.70 × 10⁴), t_p.1 ∞ c^1.42 exp (1.14 × 10⁴/T), t_p.2 ∞ c^1.47 exp (1.27 × 10⁴/T)