Table 1. Measured Apparent Second-Order Rate Constants at Indicated pH for the Reactions of the Selected Organic Model Compounds, Monochloramine, and a DOM Isolate with Br^• (k_Br•, M^–1 s^–1 or (mgC/L)⁻¹ s^–1 for DOM) and Theoretically Calculated Free Energies of Activation (ΔG^act_aq,SET, kcal mol^–1) for the Reactions of Organic Model Compounds and Monochloramine with Br^• by Electron Transfer^a.

compounds	group	pKa	pH	measured kBr• (this study) (average ± s.d.)	reported kBr• (previous studies)	σp+e	ΔGactaq,SET (kcal mol–1)
benzylamine	1° amine	9.3	10.0	(7.4 ± 0.5) × 109	n.a.		8.1
benzylamine	1° amine	9.3	7.1	(3.8 ± 0.01) × 108	n.a.		20.5
N,N-dimethylbenzylamine	3° amine	8.9	10.0	(1.7 ± 0.2) × 1010	n.a.		3.1
N,N-dimethylbenzylamine	3° amine	8.9	7.1	(9.1 ± 5.5) × 108	n.a.		20.3
4-bromophenol	aromatic	9.1	10.0	(2.8 ± 0.7) × 1010	n.a.	–2.15	0.1
4-bromophenol	aromatic	9.1	7.1	(3.5 ± 0.5) × 109	n.a.	–0.77	8.6
4-chlorophenol	aromatic	9.0	10.0	(2.0 ± 1.1) × 1010	n.a.	–2.19	0.1
4-chlorophenol	aromatic	9.0	7.1	(3.9 ± 1.3) × 109	n.a.	–0.81	7.9
anisole	aromatic	n.a.	7.1	(2.2 ± 0.4) × 109	3.3 × 10910	–0.62	6.7
benzeneb	aromatic	n.a.	7.1	3.4 × 108	n.a.	0	16.5
benzoic acid	aromatic	4.2	7.1	(2.5 ± 0.4) × 108	7.7 × 10810	–0.02	13.7
p-chlorobenzoic acid	aromatic	4.0	7.1	(3.0 ± 0.4) × 108	n.a.	0.09	14.9
ibuprofenc	aromatic	4.4	7.1	(3.8 ± 1.8) × 109	2.2 × 10912	–0.25	6.2
naphthalene	aromatic	n.a.	7.1	(5.5 ± 0.05) × 109	n.a.		5.7
phenol	aromatic	10.0	7.1	(3.9 ± 0.6) × 109	8.5 × 10910	–0.92	7.5
toluened	aromatic	n.a.	7.1	4.5 × 108	n.a.	–0.31	11.1
3-phenylpropionic acid	aromatic	4.7	7.1	(7.3 ± 0.07) × 108	n.a.		11.8
p-benzoquinone	aromatic	n.a.	7.1	(4.0 ± 0.5) × 109	n.a.		41.2
sorbic acid	olefin	4.8	7.1	(5.2 ± 0.1) × 109	n.a.		5.0
trans-cinnamic acid	olefin	4.5	7.1	(2.1 ± 0.5) × 109	n.a.		7.6
monochloramine	inorganic	1.4	7.1	(4.4 ± 1.3) × 109	n.a.		3.8
SRFA	DOM	n.a.	7.1	(1.7 ± 0.01) × 104	2.6 × 104		n.a.
oxidized SRFA (0.8 gO3/gC)	DOM	n.a.	7.1	(1.6 ± 0.01) × 104	n.a.		n.a.
oxidized SRFA (1.5 gO3/gC)	DOM	n.a.	7.1	(2.1 ± 0.3) × 104	n.a.		n.a.

^aMost k_Br• were determined in competition with ibuprofen or unless otherwise indicated. k_Br• are shown as an average and standard deviation (s.d.) of duplicates except benzene and toluene. The corresponding competition kinetics plots are shown in Figure S5.

^bSingle measurement with a poor linearity of the competition kinetics plot (R² = 0.67, Figure S5).

^ck_Br• of ibuprofen was determined in competition with 4-iodophenol with k_Br• of 4-iodophenol of 6.6 × 10⁹ M^–1 s^–1.

^dSingle measurement.

^eAll σ_p⁺ values were taken from Hansch et al.⁴⁰ except for ibuprofen, for which σ_p⁺ was estimated after a structural approximation by Lee and von Gunten.⁴¹