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 H 3 PO 4 with primary amine N 1923 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 × 10 3 /T), t p.1 ∞ c 0.241 HCI , exp(4.33 × 10 3 /T), t p.2 ∞ c 0.290 HCI exp(5.59 × 10 3 /T); for the oscillating system of acetic acid, t in ∞ c 0.883 HOAc exp(2.32 × 10 3 /T), t p.1 ∞ c 0.399 BOAc , exp(4.50 × 10 3 /T), t p.2 ∞ c 0.301 HOAc exp(5.88 × 10 3 /T); for the oscillating system of phosphoric acid, t in ∞ c 1.14   H   3 PO   4exp(7.70 × 10 4 ), t p.1 ∞ c 1.42   H   3 PO   4exp (1.14 × 10 4 /T), t p.2 ∞ c 1.47   H   3 PO   4exp (1.27 × 10 4 /T)