Ruthenium(III) Catalysis in Perborate Oxidation of 5-Oxoacids

Table 4

Oxidation rates at different acidities^a.

5-Oxoacid	10^3; (s^−1); 10^2[H^+]; (mol dm^−3)							10^3(); (s^−1)
	0.88	1.88	3.88	6.88	9.88	14.9	19.9	0.88	1.88	3.88	6.88	9.88	14.9	19.9
p-OCH3	20.27; (4.11)	21.45; (4.41)	22.86; (5.93)	23.65; (7.42)	24.26; (8.64)	27.33; (11.56)	28.70; (12.80)	16.16	17.04	16.93	16.23	15.62	15.78	15.90
p-CH3	9.13; (2.05)	11.12; (2.21)	11.43; (2.97)	11.82; (3.71)	12.13; (4.32)	13.66; (5.78)	14.35; (6.40)	7.08	8.92	8.46	8.46	7.81	7.88	7.94
p-C6H5	6.66; (1.44)	8.12; (1.61)	8.34; (2.17)	8.63; (2.71)	8.85; (3.15)	9.97; (4.22)	10.47; (4.67)	5.16	6.51	6.17	6.17	5.70	5.75	5.80
–H	6.00; (1.35)	7.31; (1.45)	7.51; (1.95)	7.77; (2.44)	7.97; (2.84)	8.98; (3.80)	9.43; (4.21)	4.65	5.86	5.56	5.33	5.13	5.18	5.22
p-Cl	1.84; (0.42)	2.25; (0.45)	2.31; (0.60)	2.39; (0.75)	2.45; (0.88)	2.77; (1.17)	2.90; (1.29)	1.43	1.80	1.71	1.64	1.58	1.59	1.60
p-Br	0.94; (0.21)	1.14; (0.23)	1.83; (0.31)	1.22; (0.38)	1.25; (0.45)	1.41; (0.59)	1.48; (0.66)	0.72	0.91	0.87	0.83	0.80	0.81	0.81
m-NO2	0.46; (0.11)	0.56; (0.11)	0.58; (0.15)	0.60; (0.18)	0.62; (0.22)	0.69; (0.33)	0.73; (0.33)	0.35	0.45	0.43	0.42	0.40	0.36	0.40

^a10³[Perborate]₀ = 1.0 mol dm⁻³; 10²[5-oxoacid]₀ = 4.0 mol dm⁻³; *10⁴[Ru(III)] = 1.0 mol dm⁻³; HOAc—H₂O = 1 : 1% (v/v); Temp. = 308 K.
Parentheses values indicate the rate constant (, s⁻¹) of uncatalyzed reactions.