Skip to main content
. Author manuscript; available in PMC: 2018 Dec 6.
Published in final edited form as: J Am Chem Soc. 2017 Nov 27;139(48):17313–17326. doi: 10.1021/jacs.7b06246

Table 1.

EPR properties of the S = ½ iron species previously observed in reaction mixtures of nonheme iron catalysts with H2O2/RCOOH or peracids

Precursor Oxidant (Temp) High g-anisotropy
(g2.7) species
% spin		 Low g-anisotropy
(g2.07) species
(2.07, 2.01, 1.96)
% spin		 ref
(TPA)FeII H2O2/AcOH (−40 °C) or mCPBA (−60°C) 2.74, 2.42, 1.53
4 – 21%		 not observed 44, 50, 54
(TPA*)FeII H2O2/AcOH or mCPBA (−40 °C) 2.58, 2.38, 1.73
43 – 50 %		 not observed 50
[(TPA*)FeIII]2O H2O2/AcOH (−85 °C) 2.58, 2.38, 1.73
observed but % not reported		 2 – 3 % 51
(BPMEN)FeII H2O2/AcOH (−70 °C) or peracids (−60 °C) 2.69, 2.42, 1.70
4–10 %		 not observed 50
(S,S-PDP)FeII H2O2/AcOH (−70 °C) H2O2/2-EhOH (−70 °C) 2.66, 2.42, 1.71
2 – 3 %
not observed		 not observed
2 – 3 %		 40, 52 53
(S,S-PDP*)FeII H2O2/AcOH (−40 to −85 °C) 2.72, 2.42, ?
7% 		not observed 48
[(S,S-PDP*)FeIII]2O H2O2/AcOH or AcOOH (−65 to −85 °C) 2.52, 2.41, 1.80
observed but % not reported		 <2 % 51, 53
(PyNMe3)FeII AcOOH (−40 °C) not observed 40 % 54

Abbreviations used: BPMCN = N,N′-dimethyl-N,N′-bis(2-pyridylmethyl)-trans-1,2-diaminocyclohexane; BPMEN = N,N′-dimethyl-N,N′-bis(2-pyridylmethyl)ethane-1,2-diamine; mCPBA = meta-chloroperbenzoic acid; PDP = N,N′-bis(2-pyridylmethyl)-2,2′-bipyrrolidine; PDP* = N,N′-bis(3,5-dimethyl-4-methoxy-2-pyridylmethyl)-2,2′-bipyrrolidine; PyNMe3 = 3,6,9-trimethyl-3,6,9-triaza-1(2,6)-pyridinacyclodecaphane; 2-EhOH = 2-ethylhexanoic acid; TPA = tris(2-pyridylmethyl)amine; TPA* = tris(3,5-dimethyl-4-methoxy-2-pyridylmethyl)amine.