TABLE 3.

Properties of metal complexes with different steric hindrance effect.

Complex	Substituent	E1/2 (V)	WS conditions	TON	TOF (s−1)	FE (%)	ref
24	H	—	3.7 M H2O2, pH 3.9	830	86	74–81	Lee et al. (2014)
	Me	—	3.7 M H2O2, pH 3.9	58,000	27	74–81
	tBu	—	3.7 M H2O2, pH 3.9	—	—	74–81
25a	Me	—	0.125 M CAN	145	0.14	—	Fillol et al. (2011)
	iPr	—	0.150 M CAN	14	0.18	—	Panchbhai et al. (2016)
25b	—	—	0.125 M CAN	63	0.0464	—	Fillol et al. (2011)
26a	H	—	0.2 M CAN	400	0.002	—	Kaveevivitchai et al. (2012)
26b	Me	—	0.2 M CAN	155	0.008	—
26c	2 d Me	—	0.2 M CAN	—	—	—
27a	—	—	0.2 M CAN	9	50	—	Kaveevivitchai et al. (2012)
27b	—	—	0.2 M CAN	66	10	—
27c	—	—	0.2 M CAN	—	—	—
28	Me	—	[(DMF)H]OTf	10	6,700	94	(Kilgore et al., 2011b; Wiese et al., 2012)
	Benzyl	−0.83, −1.12 c	[(DMF)H]OTf	—	130	—
	n-Bu	−0.93, −1.23 c	[(DMF)H]OTf	—	1,820	—
	2-phenylethyl	−0.90, −1.16 c	[(DMF)H]OTf	9	1,080	95
	2,4,4-trimethylpentyl	−0.89, −1.17 c	[(DMF)H]OTf	—	69	—
	cyclohexyl	−0.60, −1.12 c	[(DMF)H]OTf	—	69	—
	phenyl	−0.84, −1.02 c	[(DMF)H]OTf	—	720	—
12	H		5 mM CAN, 0.1M HNO3, H2O	723	0.2	58	Corbucci et al. (2019)
	Me		5 mM CAN, 0.1M HNO3, H2O	1,010	0.2	81
	Et		5 mM CAN, 0.1M HNO3, H2O	905	1.1	71
	nPr	—	5 mM CAN, 0.1M HNO3, H2O	863	1.5	70
	iPr	—	5 mM CAN, 0.1M HNO3, H2O	1,017	1.05	80
	Bu	—	5 mM CAN, 0.1M HNO3, H2O	875	1.37	70
	Oct	—	5 mM CAN, 0.1M HNO3, H2O	945	1.5	76
14	F	1.38 a	1.5 mM CAN	9,822	790	90	Xie et al. (2018)
	Cl	1.28 a	1.5 mM CAN	26,992	364	98
	Br	1.28 a	1.5 mM CAN	7,371	88	67
29a	H	0.80 a	0.2 M CAN	390	20	—	Kaveevivitchai et al. (2012)
	t-butyl	0.71 a	0.2 M CAN	667	63	—
29b	t-butyl	0.80 a	0.2 M CAN	218	33	—
29c	t-butyl	0.66 a	0.2 M CAN	94	3	—
30	H	0.76 a	0.2 M CAN	1,170	13	—	Kaveevivitchai et al. (2012)
	t-butyl	0.65 a	0.2 M CAN	274	20	—
31	H	0.75 a	0.2 M CAN	370	50	—	Kaveevivitchai et al. (2012)
	t-butyl	0.68 a	0.2 M CAN	310	40	—
32	R = R' = H	0.77, 1.40 b	CPE d	3.6	—	94	(Wang et al., 2017; Hessels et al., 2020)
	R = H, R' = Me	0.87, 1.40 b	CPE d	13.0	—	97
	R = R' = Me	1.15, 1.38 b	CPE d	15.2	—	93

^aPotential versus SCE.

^bPotential versus NHE.

^cPotential versus ferrocene.

^dCPE: controlled potential electrolysis.