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. 2013 Oct 15;9(11):5004–5020. doi: 10.1021/ct4007585

Table 1. Iron Complexes Investigated in the Present Study.

entry system symm.a Fe ox.b Sc T/K δ/mm s–1d δ4.2K/mm s–1d ΔEQ/mm s–1e ref
1 Fe(phen)2(NCS)2 (LS) C2 2 0 77 0.34 0.37 0.34 (48)
2 Fe(LN4)(NCS)2 (LS) C1 2 0 80 0.44 0.47 0.77 (49)
3 {Fe[HC(3,5-Me2pz)3]2}I2 (LS) C1 2 0 4.2 0.46 0.46 0.21 (50)
4 Fe(OEP)(CO) C4v 2 0 4.2 0.27 0.27 1.84 (51)
5 Na2[Fe(CN)5(NO)] C4v 2 0 77 –0.18 –0.15 +1.72 (52)
6 Na2[Fe(CN)5(ON)] C4v 2 0 77 0.00 0.03 2.75 (52)
7 Na2[Fe(CN)5(η2-NO)] C1 2 0 77 0.01 0.04 2.86 (52)
8 Cp2Fe D5d 2 0 80 0.53 0.56 +2.38 (53)
9 [CpFe(CO)3]PF6 C1 2 0 78 0.05 0.08 1.88 (53)
10 [CpFe(CO)2]Cl C1 2 0 4.2 0.27 0.27 1.82 (14)
11 [CpFe(CO)2]Br C1 2 0 78 0.25 0.28 1.87 (54)
12 [CpFe(CO)2]Me C1 2 0 78 0.08 0.11 1.76 (55)
13 Fe(CO)3(butadiene) C1 0 0 77 0.03 0.06 –1.46 (53)
14 Fe(CO)3(cyclo-butadiene) C1 0 0 78 0.02 0.05 1.52 (55)
15 Fe(CO)5 D3h 0 0 143 –0.18 –0.12 +2.52 (56)
16 Et4N[Fe(CO)4H] C3v 0 0 77 –0.17 –0.14 1.36 (57)
17 [Fe(bipy)3](ClO4)2 D3 2 0 77 0.33 0.36 0.39 (58)
18 [Fe(phen)3](ClO4)2 D3 2 0 77 0.34 0.37 0.23 (58)
19 [Fe(terpy)2]Cl2 D2d 2 0 80 0.27 0.30 –1.00 (59)
                   
20 Fe(phen)2(NCS)2 (HS) C2 2 2 77 1.01 1.04 2.82 48
21 Fe(LN4)(NCS)2 (HS) C1 2 2 80 1.10 1.13 2.51 (49)
22 {Fe[HC(3,5-Me2pz)3]2}I2 (HS) C1 2 2 190 1.02 1.09 3.86 (50)
23 (PPh4)2[Fe(DTSQ)2] D2d 2 2 4.2 0.67 0.67 –4.01 (60)
24 (PPh4)2[Fe(SPh)]4] C2 2 2 4.2 0.66 0.66 –3.24 (60)
25 Fe(phen)2Cl2 C2 2 2 77 1.07 1.10 3.27 (55)
26 FePy4Cl2 D4 2 2 4.2 1.10 1.10 –3.14 (55)
27 Na[Fe(TPpivP)(OAc)]f C1 2 2 4.2 1.05 1.05 +4.25 (61)
28 Na[(DBC)(THF)2][Fe(TPP)(OPh)] C1 2 2 4.2 1.03 1.03 +4.01 (62)
29 Fe(TMP)2(NCS)2 C2 2 2 90 1.07 1.11 3.27 (63)
30 Fe(LN4′)(NCS)2 C1 2 2 80 1.16 1.19 2.14 (64)
31 [Fe(H2O)6]SO4 D2h 2 2 5 1.39 1.39 3.38 (65)
32 (Et4N)2[FeCl4] Td 2 2 4.2 1.00 1.00 3.30 (66)
33 (Et4N)2[FeBr4] Td 2 2 4.2 0.97 0.97 3.23 (67)
                   
34 Fe(OEP) Ci 2 1 4.2 0.59 0.59 +1.60 (68)
35 Fe(TPP) D2h 2 1 4.2 0.52 0.52 +1.51 (68)
                   
36 Fe(thpu)(Hthpu) (LS) C1 3 1/2 80 0.28 0.31 3.09 (69)
37 [Fe(acpa)2]PF6 (LS) C2 3 1/2 78 0.25 0.28 2.24 (70)
38 [Fe(bipy)3](ClO4)3 D3 3 1/2 80 0.06 0.09 1.90 (71, 72)
39 [Fe(phen)3](ClO4)3 D3 3 1/2 80 0.10 0.13 1.84 (71, 72)
40 [Fe(terpy)2](ClO4)3 D2d 3 1/2 77 0.07 0.10 –3.43 (72)
41 [Fe-trans-(cyclam)(N3)2]PF6 Ci 3 1/2 80 0.28 0.31 –2.24 (73)
42 Fe(OEP)(PyMe2)2 D2h 3 1/2 4.2 0.26 0.26 2.15 (74)
                   
43 Fe(thpu)(Hthpu) (HS) C1 3 5/2 241 0.47 0.57 0.81 (69)
44 [Fe(acpa)2PF6 (HS) C2 3 5/2 320 0.33 0.46 0.53 (70)
45 (n-Pr)4N[Fe(SEt)4] S4 3 5/2 4.2 0.25 0.25 0.62 (75)
46 FeCl(MBTHx)2 C1 3 5/2 4.2 0.43 0.43 0.98 (76)
47 K[Fe(EDTA)(H2O)] C2 3 5/2 4.2 0.60 0.60 0.76 (77)
48 Fe(acac)3 C3 3 5/2 78 0.53 0.56 0.64 (78)
49 Fe(tfa)3 C3 3 5/2 78 0.53 0.56 0.67 (78)
50 [Fe(H2O)6]Cl3 D2h 3 5/2 78 0.50 0.53 0.00 (79)
51 Et4N[FeCl4] Td 3 5/2 77 0.30 0.33 0.00 (80)
52 Et4N[FeBr4] Td 3 5/2 77 0.36 0.39 0.00 (80)
53 FeCl3 Oh 3 5/2 78 0.53 0.56 0.00 (81)
54 KFeF4 Oh 3 5/2 4.2 0.69 0.69 0.00 (55)
                   
55 Fe(dtc-Et2)2Cl Cs 3 3/2 4.2 0.50 0.50 2.70 (82)
56 (Et4N)2[Fe(η4-MAC*)Cl] C1 3 3/2 4.2 0.25 0.25 +3.60 (83)
57 Fe(mnt)2(idzm) C2 3 3/2 77 0.36 0.39 2.64 (84)
                   
58 trans-[Fe(TMC)(O)(NCCH3)](OTf)2 C1 4 1 4.2 0.17 0.17 1.24 (85)
59 [Fe(N4Py)(O)](ClO4)2 Cs 4 1 4.2 –0.04 –0.04 +0.93 (86)
60 Et4N[Fe(η4-MAC*)Cl] C1 4 2 4.2 –0.04 –0.04 –0.89 (83)
61 Fe(PPh3)2(″S2″)2 C2v 4 1 4.2 0.16 0.16 1.52 (87)
62 Fe(PPh3)(″S2″)2 Cs 4 1 4.2 0.12 0.12 3.03 (87)
                   
63 PPh4[Fe(B*)(O)] C1 5 1/2 4.2 –0.42 –0.42 +4.25 (88)
64 [Fe(cyclam-acetate)(N)]PF6 C1 5 1/2 4.2 –0.02 –0.02 –1.60 (26, 89)
                   
65 [Fe(Me3cyclam-acetate)(N)](PF6)2 C1 6 0 4.2 –0.29 –0.29 +1.53 (27)
66 K2FeO4 Td 6 1 78 –0.85 –0.82 0.00 (90)
a

Approximate point group symmetry of the molecular structure.

b

Fe oxidation state.

c

Fe spin state.

d

Referred to α-iron at room temperature.

e

If available, the experimental sign of ΔEQ (+ or −) is given; in all other cases, we show the absolute value of quadrupole splittings.

f

In the computation, the large TPpivP ligand was substituted with porphine. The following abbreviations are used in the table: LS = low spin state, HS = high spin state, phen = 1,10-phenanthroline, LN4 = N-[(1-H-imidazol-4-yl)methylene]-N′-(1-pyridin-2-yl-ethylidene)-2,2-dimethyl-propane-1,3-diamine, pz = pyrazolyl ring, OEP = dianion of octaethylporphyrin, bipy =2,2′-bipyridine, terpy = 2,2′:6′2″-terpyridine, DTSQ = bis(dithiosquarato-S,S′) dianion, TPpivP = ″pivalamide-picket-fence″ porphyrin, DBC = dibenzo-18-crown-6), TPP = tetraphenylporphyrinate, TMP = 3,4,7,8-tetramethyl-1,10-phenanthroline), LN4′ = N,N′-bis[(1H-imidazol-4-yl)methylene]-2,2-dimetyl-propane-1,3-diamine, cyclam = 1,4,8,11-tetraazacyclotetradecane, thpu = dianion of pyruvic acid thiosemicarbazone, acpa = anion of N-(1-acetyl-2-porpylidene)(2-piridylmethyl)amine), MBTHx = bis(N-methylbenzothiohydroxamato) anion, EDTA = tetra-anion of ethylenediaminetetraacetic acid, acac = acetylacetonate, tfa = trifluoroacetylacetonate, dtc-Et2 = diethyldithiocarbamate, MAC* = tetra-anion of 1,4,8,11-tetraaza-13,13-diethyl-2,2,5,5,7,7,10,10-octamethyl-3,6,9,12,14-pentaoxocyclotetradecane, mnt = cis-1,2-dicyano-1,2-ethylenedithiolato, idzm =2-(p-pyridyl)-4,4,5,5-tetramethylimidazolinium, TMC = 1,4,8,11-tetramethyl-1,4,8,11-tetraazacyclotetradecane, ″S2″ = 1,2-benzenedithiolato-S,S′ dianion, B* = tetra-anion of 3,3,6,6,9,9-hexamethyl-3,4,8,9-tetrahydro-1H-1,4,8,11-benzotetraazacyclotridecine-2,5,7,10(6H,11H)-tetraone. Note that counterions were not included in the computations.