. Author manuscript; available in PMC: 2011 Sep 20.

Published in final edited form as: Inorg Chem. 2010 Sep 20;49(18):8310–8322. doi: 10.1021/ic100870v

Table 1.

⁵⁷Fe hyperfine parameters of 1-F and 1-OH and related complexes. Experimental 4.2 K data were analyzed with eq 1.

Site	System	δ (mm/s)	ΔE_Q (mm/s)	η	A_x/g_nβ_n (T)^a	A_y/g_nβ_n (T)^a	A_z/g_nβ_n (T)^a	A_iso/g_nβ_n (T)
Fe^III	1-F	0.45	1.50	4.3	−52(2)^b	−49(2)	−46(2)	−48.7
	1-OH	0.40	−0.60	5.1	−52(2)	−52(2)	−43(2)	−49.2

	RNR R2 Int. X^c	0.56	−0.90	0.5	−54.1	−52.6	−53.4	−53.4
	5^d	0.48	1.60	1.0	−47	−47	−47	−47
	6^e	0.50	1.30	1.6	−49	−49	−49	−49
	7^f	0.56	0.90	−0.3	−55	−51	−55	−53.7

Fe^IV	1-F	0.10	0.60	−0.7	27(2)^b	19(2)	31(2)	25.5
	1-OH	0.09	−0.40	10.0	29(2)	18(3)	23(2)	23.6

	RNR R2 Int. X^c	0.26	−0.60	2.7	20.0	26.8	26.8	24.5
	5^d	0.08	0.50	1.0	15	27	27	23
	6^e	0.10	1.14	0.1	17	25	20	21
	7^f	0.19	0.80	−1.0	19	27	17	21

Because the g-tensors of 1-OH and 1-F are isotropic, the coordinates x, y, and z of the Fe^III and Fe^IV sites cannot be related experimentally for samples containing randomly oriented molecules. However, they become correlated through the D^e/J mixing when the data are analyzed with eq 4. We have labeled the coordinates such that they agree best with the DFT results. The coordinates of complexes 5–7 and intermediate X have not been correlated and are probably better labeled with 1, 2, 3 rather than x,y,z.

The uncertainties of the individual A-tensor components are estimated to be ± 2 T. However, the A_iso values are better than ± 0.5 T.

Data from ref. 17.

Data from ref. 40.

Data from ref. 42.

Data from ref. 51.