Table 6.
Pure and Broken Symmetry Spin-State Expectation Values for the Iron Complexes Examined in this Studya
| complex | Fe oxidation | 〈S2〉pure |
|
OLYP | OPBE | PW91 | BP86 | B3LYP | B3LYP* | |||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| //B3LYP | //OLYP | //B3LYP* | //OLYP | |||||||||
| [Fe(SEt)4]− | Fe3+ | 8.75 | n/a | 8.76 | 8.76 | 8.76 | 8.76 | 8.77 | 8.77 | 8.77 | 8.77 | |
| [FeS4C8O4]2− | Fe2+ | 6.00 | n/a | 6.06 | 6.07 | 6.02 | 6.02 | 6.01 | 6.01 | 6.01 | 6.01 | |
| [Fe(SPh)4]2− | Fe2+ | 6.00 | n/a | 6.03 | 6.03 | 6.02 | 6.02 | 6.02 | 6.00 | 6.02 | 6.02 | |
| [Fe(H2O)5(NO)]2+ | {FeNO}7 | 3.75 | 5.75 | 4.28 | 4.29 | 4.12 | 4.14 | 4.53 | 4.49 | 4.45 | 4.41 | |
| [Fe(NO)(dtci-Pr2)2] | {FeNO}7 | 0.75 | 2.75 | 0.86 | 0.83 | 0.79 | 0.79 | 1.74 | 1.37 | 1.36 | 1.13 | |
| [Fe(SPh)2(NO)2]− | {Fe(NO)2}9 | 0.75 | 4.75 | 1.02 | 0.95 | 0.82 | 0.83 | 2.65 | 2.07 | 2.12 | 1.67 | |
| [Fe(SC2H3N3)(SC2H2N3)(NO)2] | {Fe(NO)2}9 | 0.75 | 4.75 | 1.08 | 0.99 | 0.84 | 0.86 | 2.54 | 2.08 | 2.08 | 1.71 | |
| MAD (〈S2〉pure) | 0.19 | 0.17 | 0.09 | 0.10 | 0.79 | 0.58 | 0.58 | 0.43 | ||||
| [Fe2S2(S2-o-xyl)2]2− | 2*Fe3+ | 0.0 | 5.00 | 4.31 | 4.27 | 4.04 | 4.08 | n/ac | 4.65 | n/ac | 4.55 | |
| [Fe2S2(OPh-p-CH3)4]2− | 2*Fe3+ | 0.0 | 5.00 | 4.47 | 4.45 | 4.21 | 4.22 | 4.80 | 4.74 | 4.72 | 4.67 | |
| [Fe2S2(C4H4N)4]2− | 2*Fe3+ | 0.0 | 5.00 | 4.31 | 4.27 | 3.99 | 4.03 | 4.69 | 4.64 | 4.59 | 4.55 | |
| [Fe2(NO)2(Et-HPTB)(O2CPh)]2+ | 2*{FeNO}7 | 0.0 | 3.00 | 4.24 | 4.20 | 3.62 | 3.67 | n/ac | 4.90 | n/ac | 4.69 | |
| [Fe(NO)2{Fe(NO)(N(CH2CH2S)3)}-S,S′] | {FeNO}7 {Fe(NO)2}9 |
2.00 | 3.00 | 3.06 | 2.76 | 2.32 | 2.38 | 5.54 | 4.72 | 4.83 | 4.11 | |
| MAD ( ) | 0.64 | 0.69 | 0.81 | 0.79 | 1.02 | 0.92 | 0.84 | 1.01 | ||||
| [Fe4S4(SPh)4]2− | 4*Fe2.5+ | 0.0 | 9.00 | 7.26 | 7.02 | 6.23 | 6.36 | n/ac | 8.24 | n/ac | 7.99 | |
| [Fe4S4(OPh)4]2− | 4*Fe2.5+ | 0.0 | 9.00 | 7.59 | 7.42 | 6.71 | 6.81 | 8.67 | 8.43 | 8.45 | 8.24 | |
| [Fe4S4(SPh)2Cl2]2− | 4*Fe2.5+ | 0.0 | 9.00 | 7.35 | 7.11 | 6.37 | 6.47 | 8.47 | 8.28 | 8.29 | 8.05 | |
| [Fe4S4(OPh)2Cl2]2− | 4*Fe2.5+ | 0.0 | 9.00 | 7.49 | 7.34 | 6.64 | 6.75 | 8.61 | 8.37 | 8.40 | 8.16 | |
| [Fe4S4Cl4]2− | 4*Fe2.5+ | 0.0 | 9.00 | 7.43 | 7.26 | 6.58 | 6.67 | 8.56 | 8.31 | 8.32 | 8.09 | |
| [Fe4S4(SCH2CO2Et)4]2− | 4*Fe2.5+ | 0.0 | 9.00 | 7.20 | 7.08 | 6.13 | 6.18 | n/ac | 8.21 | n/ac | 7.97 | |
| [Fe4(NO)4(μ3-S)4] | 4*{FeNO}7 | 0.0 | 6.00 | 1.70 | 0.60 | 0.23 | 0.32 | 7.12 | 5.15 | 5.58 | 4.07 | |
| [Fe4(NO)4(μ3-S)4]− | 2*{FeNO}7.5 2*{FeNO}7 |
0.75 | 5.75 | 3.13 | 1.82 | 0.85 | 1.24 | 7.46 | 6.50 | 5.88 | 5.44 | |
| MAD( ) | 2.08 | 2.51 | 3.25 | 3.12 | 0.75 | 0.52 | 0.69 | 0.92 | ||||
a
See also Supporting Information Table S6 for the B3LYP and B3LYP* values using ORCA in combination with a CP(PPP) basis set on Fe and a TZVP basis set on the remaining atoms.
b
For the mononuclear Fe complexes, the expectation value of S2 is for the unrestricted, rather than broken symmetry, state. WC refers to weak-coupling limit.
c
The OLYP/STO-TZP COSMO geometry is used instead. See Computational Methods section for details.