. 2021 Apr 8;6(15):10333–10342. doi: 10.1021/acsomega.1c00683

Table 1. Kinetic Rate Constants for the Hydrolysis Reaction of the Substituted 7-Diethylaminocoumarin Schiff Bases (IC1–IC5; 8 μM) at T = 25.0 °C.

Schiff bases	pK_a1	pK_a2	10⁴k_H+ (s^–1 M^–1)^a	k_2H+ (s^–1 M^–1)^a	10³k₀ (s^–1)^b
IC1	4.29 ± 0.05	1.09 ± 0.01	1600 ± 100	131 ± 5	<21
IC2	3.66 ± 0.28	1.15 ± 0.01	21 ± 6	0.27 ± 0.01	<0.1
IC3	4.10 ± 0.03	1.10 ± 0.01	3026 ± 5	169 ± 5	<31
IC4	3.00 ± 0.13	1.10 ± 0.02	36 ± 8	0.70 ± 0.02
IC5	3.26 ± 0.07	1.17 ± 0.18	1.3 ± 0.4	0.052 ± 0.001	<0.03

Obtained from the fitting of the kinetics data of Table S1 with eq 2.

Obtained from the experimental k_obs values at pH 5.