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

Table 6

Influence of dielectric constant of the medium on ruthenium(III) catalysis^a.

	AcOH—H2O; %; (v/v)	10^2 [H^+]; (mol dm^−3)	10^3; (s^−1)							10^3(); (s^−1)
			p-OCH3	p-CH3	p-C6H5	–H	p-Cl	p-Br	m-NO2	p-OCH3	p-CH3	p-C6H5	–H	p-Cl	p-Br	m-NO2
53.18	30–70	0.88	7.26; (4.81)	3.62; (2.40)	2.64; (1.75)	2.38; (1.58)	0.73; (0.49)	0.37; (0.25)	0.17; (0.12)	2.45	1.22	0.88	0.80	0.24	0.12	0.05
46.48	40–60	0.88	12.95; (4.47)	6.47; (2.24)	4.72; (1.63)	4.25; (1.47)	1.30; (0.45)	0.66; (0.23)	0.32; (0.12)	8.48	4.23	3.08	2.78	0.85	0.43	0.21
39.78	50–50	0.88	18.27; (4.11)	9.13; (2.05)	6.66; (1.49)	6.00; (1.35)	1.85; (0.42)	0.94; (0.21)	0.46; (0.11)	14.16	7.08	5.16	4.65	1.43	0.72	0.36
33.08	60–40	0.88	24.66; (3.86)	12.32; (1.93)	8.99; (1.41)	8.10; (1.27)	2.49; (0.39)	1.27; (0.19)	0.63; (0.09)	20.79	10.39	7.58	6.83	2.10	1.07	0.53
26.08	70–30	0.88	30.34; (3.68)	15.17; (1.84)	11.07; (1.34)	9.97; (1.21)	3.07; (0.37)	1.56; (0.19)	0.77; (0.09)	26.66	13.33	9.72	8.76	2.70	1.37	0.68
53.18	30–70	14.9	24.63; (11.77)	12.31; (5.89)	8.98; (4.29)	8.09; (3.87)	2.49; (1.19)	1.27; (0.61)	0.63; (0.30)	12.86	6.42	4.68	4.22	1.30	0.66	0.32
46.48	40–60	14.9	24.99; (11.10)	12.49; (5.55)	9.11; (4.05)	8.21; (3.65)	2.53; (1.13)	1.28; (0.57)	0.63; (0.29)	13.88	6.94	5.06	4.56	1.40	0.71	0.35
39.78	50-50	14.9	27.33; (11.56)	13.66; (5.78)	9.97; (4.22)	8.98; (3.80)	2.77; (1.17)	1.28; (0.57)	0.63; (0.29)	15.78	7.88	5.75	5.18	1.59	0.81	0.40
33.08	60–40	14.9	30.37; (10.83)	15.18; (5.41)	11.08; (3.95)	9.98; (3.56)	3.07; (1.09)	1.56; (0.56)	0.77; (0.28)	19.55	9.77	7.13	6.42	1.98	1.00	0.49
26.08	70–30	14.9	36.79; (10.34)	18.39; (5.17)	13.42; (3.77)	12.09; (3.40)	3.72; (1.05)	1.90; (0.54)	0.94; (0.27)	26.33	13.16	9.60	8.65	2.66	1.35	0.67

^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.