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. Author manuscript; available in PMC: 2012 Mar 21.
Published in final edited form as: Inorg Chem. 2011 Feb 15;50(6):2302–2320. doi: 10.1021/ic1020127

Table 3.

Calculated Fe-Fe and Fe-ligand distances (Å), net spin populations (NSP) of Fe1(III), Fe2(III) and Tyr122·, broken symmetry state energies E (eV), 57Fe Mössbauer isomer shift (δ, mm s−1), quadrupole splittings (ΔEQ, mm s−1) and η for the Fe1(III)Fe2(III)-Tyr122· active site modelsa

(a)
A(Obr,H2Ot2)		 (b)
A(Obr,H2Ot1)		 (c)
A(OH−br,OH−br)		 (d)
A(Obr,OH−br)-
Asp84H		 (e)
A(OH−br,OH−br)-
Asp84H		 (f)
A(Obr,OH−br)		 exp b
Fe1-Fe2 3.151 3.131 3.053 2.881 3.079 2.889
Fe1-O1 1.782 1.795 1.959 1.781 1.933 1.785
Fe2-O1 1.826 1.818 2.046 1.848 2.159 1.847
Fe1-O2 2.744 2.412 2.003 2.084 1.993 2.016
Fe2-O2 2.278 2.506 2.023 2.111 2.081 2.075
Fe1-O3 2.215 2.196 2.345 2.129 2.103 2.248
Fe1-N-His118 2.123 2.152 2.238 2.207 2.148 2.276
Fe2-N-His241 2.206 2.150 2.220 2.238 2.167 2.239
Fe1-O-Asp84 2.041 2.090 2.011 3.032 2.962 2.065
Fe1-O-Glu115 1.995 2.006 2.001 1.975 1.946 2.033
Fe2-O-Glu115 2.245 2.165 2.153 2.427 2.224 2.271
Fe2-O-Glu204 2.014 2.013 1.966 2.023 1.916 2.066
Fe2-O-Glu238 2.042 2.037 2.060 2.032 1.994 2.060
NSP(Fe1) 4.05 4.04 4.16 4.02 4.20 3.85
NSP(Fe2) −4.05 −4.04 −4.14 −4.06 −4.13 −4.04
NSP(C1-Tyr122·) −0.39 −0.39 −0.39 −0.38 −0.39 −0.29
NSP(C2-Tyr122·) 0.10 0.10 0.10 0.09 0.09 0.08
NSP(C3-Tyr122·) −0.24 −0.24 −0.24 −0.22 −0.22 −0.18
NSP(C4-Tyr122·) −0.03 −0.03 −0.03 −0.04 −0.05 −0.02
NSP(O-Tyr122·) −0.31 −0.31 −0.31 −0.30 −0.30 −0.25
NSP(C5-Tyr122·) −0.25 −0.25 −0.25 −0.24 −0.25 −0.19
NSP(C6-Tyr122·) 0.10 0.10 0.10 0.10 0.10 0.08
E −885.6346 −885.7093 −885.5971 −885.2601 −884.7301 −885.3473
δ(Fe1, Fe2) (0.47, 0.54) (0.50, 0.53) (0.48, 0.53) (0.48, 0.54) (0.50, 0.54) (0.44, 0.56) (0.45, 0.55)
ΔEQ(Fe1, Fe2) (−1.72, −1.78) (−1.63, −1.70) (0.98, 0.64) (−0.64, −1.46) (2.50, 0.65) (−1.06, −1.30) (−2.44, −1.62)
η(Fe1, Fe2) (0.44, 0.14) (0.38, 0.26) (0.53, 0.82) (0.71, 0.63) (0.54, 0.51) (0.36, 0.56) (0.2, 0.6)
pKa: c
(e) → (d) + H+ 1.27
(a) → (f) + H+ 15.03
(b) → (f) + H+ 16.29
(c) → (f) + H+ 14.40
a

The diiron centers of these models are shown in Figures 6a-f

b

Taken from Ref. 105

c

Calculated according to equation 5, with the relevant broken-symmetry state energies given in this table.