Ref. p. 329]
3 Radicals in metal complexes
Substance
Generation / Matrix or
Solvent / Method / T [K]
65
g-Factor /
a-Value [mT]
Ref. /
add. Ref.
gzz = 2.0587
00Fuk
gzz = 2.0499
00Fuk
gzz = 2.0451
00Fuk
gzz = 2.0558
00Fuk
2.0031
85Oku
3.3 Complexes of group 2 (Be, Mg, Ca, Sr, Ba)
[BaO2] •+
chemical reaction
Ba2+ O2•−
acetonitrile
ESR / 143
[CaO2] •+
chemical reaction
Ca2+ O2•−
acetonitrile
ESR / 143
[MgO2] •+
chemical reaction
Mg2+ O2•−
acetonitrile
ESR / 143
[O2Sr] •+
chemical reaction
Sr2+ O2•−
acetonitrile
ESR / 143
[C6H5BrMgN] •
chemical reaction
14
N
THF
•
MgBr
ESR / 298
[C6H5MgNO2] •+
H2N
chemical reaction
•+
O
Mg
HO
water, pH 6.6
ESR / 294
•+
6
5
4
electrochemical or
photosensitized reaction
dimethylsulfoxide
O
O
HO
ESR / 298
O
O
Ca
Landolt-Börnstein
New Series II/26A2
2.00384
88Pra
14
O
[C6H7CaO6] •+
N: 0.980
H(p): 0.575
H(o): 0.520
H(m): 0.073
N: 0.348
H(3): 0.122
H(6): 0.059
H(5): 0.495
H(NH): 0.282
H(NH'): 0.297
86Gex
H(4): 0.1423
H(5): 0.0063
H(6): 0.0261
H(6): 0.0178
66
3.3 Complexes of group 2 (Be, Mg, Ca, Sr, Ba)
[Ref. p. 329
Substance
Generation / Matrix or
Solvent / Method / T [K]
g-Factor /
a-Value [mT]
Ref. /
add. Ref.
[C7H7BrMgN] •
chemical reaction
2.0031
85Oku
14
N
THF
•
MgBr
ESR / 298
N: 1.050
H(o): 0.520
H(m): 0.110
H(CH3): 0.520
CH3
[C7H7BrMgNO] •
chemical reaction
85Oku
2.0031
14
N
THF
•
MgBr
ESR / 298
N: 1.100
H(o): 0.500
H(m): 0.05
OCH3
[C9H4BaO3] •+
chemical reaction
HMPTA
•−
O
enthalpy for ion pairing
O
[C9H4CaO3] •+
chemical reaction
HMPTA
•−
O
[C9H4MgO3] •+
chemical reaction
HMPTA
•−
O
ESR / 298
Mg2+
O
[C9H8MgNO4] •
2–
H(2 H): 0.088
H(2 H): 0.103
chemical oxidation
•
O
Mg
H3C
84Ech
enthalpy for ion pairing
O
H
N
H(4 H): 0.094
enthalpy for ion pairing
O
OOC
84Ech
ESR / 373
Ca2+
O
−
H(4 H): 0.093
ESR / 298
Ba2+
O
84Ech
O
water, TRIS buffer, pH 8.5
ESR / RT
87Kal
14
N: 0.35
H(aromatic, 1 H): 0.045
H(aromatic, 1 H): 0.05
H(sidechain, 3 H): 0.48
H(sidechain, 2 H): 0.32
H(N-H): 0.35
data on deuterated compounds available
Landolt-Börnstein
New Series II/26A2
Ref. p. 329]
3 Radicals in metal complexes
Substance
Generation / Matrix or
Solvent / Method / T [K]
[C10H10MgNO4] •
2–
•
HN
water, TRIS buffer, pH 8.0
ESR / RT
O
Mg
H3C
O
[C11H10MgNO5] •
2–
•
COO
N
water, TRIS buffer, pH 7.5
ESR / RT
O
Mg
O
[C11H11MgN2O5] •
−
2–
water, TRIS buffer, pH 8.0
ESR / RT
HN
O
HN
O
Mg
O
H3C
[C13H14MgN3O4] •
H
N
N
2–
•
HN
O
H3C
O
water, TRIS buffer
ESR / RT
Mg
2–
•
HN
O
H3C
O
water, TRIS buffer
ESR / RT
Mg
Landolt-Börnstein
New Series II/26A2
87Kal
14
N: 0.64
H(aromatic, 1 H): 0.05
H(aromatic, 1 H): 0.12
H(aromatic, 1 H): 0.5
H(sidechain, 2 H): 0.44
H(sidechain, 1 H): 0.42
H(sidechain, 1 H): 0.086
87Kal
14
N: 0.30
H(aromatic): 0.04
H(aromatic): 0.045
H(sidechain, 3 H): 0.48
H(sidechain, 2 H): 0.26
H(N-H): 0.30
87Kal
14
N: 0.35
H(aromatic, 2 H): 0.045
H(sidechain, 3 H): 0.48
H(sidechain, 2 H): 0.32
H(N-H): 0.35
chemical oxidation
COO−
H2N
N: 0.35
H(aromatic, 1 H): 0.045
H(aromatic, 1 H): 0.053
H(sidechain, 3 H): 0.48
H(sidechain, 1 H): 0.32
H(N-H): 0.35
chemical oxidation
COO−
[C13H17MgN2O4] •
14
chemical oxidation
•
OOC
Ref. /
add. Ref.
87Kal
chemical oxidation
−
HO
g-Factor /
a-Value [mT]
chemical oxidation
COO−
H3C
67
87Kal
14
N: 0.35
H(aromatic, 2 H): 0.05
H(sidechain, 3 H): 0.48
H(sidechain, 2 H): 0.32
H(N-H): 0.35
68
3.3 Complexes of group 2 (Be, Mg, Ca, Sr, Ba)
Substance
[C15H17MgN4O7] •
O
O
•
H
N
N
H
HN
2–
H3C
O
Generation / Matrix or
g-Factor /
Solvent / Method / T [K] a-Value [mT]
Ref. /
add. Ref.
chemical oxidation
87Kal
water, TRIS buffer,
pH 7.0
O
Mg
O
[Ref. p. 329
ESR / RT
NH
14
N: 0.25
H(aromatic, 2 H): 0.055
H(sidechain, 3 H): 0.48
H(sidechain, 2 H): 0.22
H(N-H): 0.25
O
−
O
[C16H14MgNO4] •
2–
chemical oxidation
COO−
•
HN
O
H3C
O
water, TRIS buffer
ESR / RT
Mg
[C18H14CaN2O8] •+
chemical reaction
87Kal
14
N: 0.35
H(aromatic, 1H): 0.045
H(aromatic, 1H): 0.05
H(sidechain, 3 H): 0.48
H(sidechain, 2 H): 0.32
H(N-H): 0.35
2.0044
98Ito
14
MeOOC
COOMe
Me
acetonitrile
•−
N
ESR / 298
2+
Ca
MeOOC
N
N(2 N: N(1), N(6)):
0.101
H(3): 0.150
H(8): 0.121
H(1, CH3): 0.091
O
O
electrochemistry
[C18H14MgN2O2] •+
•+
chemical reaction
2.0029
methanol
H: 0.324
H: 0.0676
H: 0.022
H: 0.005
H(2 H): 0.0005
H(2 H): 0.0003
H(CH3): 0.062
H(CH3): 0.003
14
N: 0.324
14
N: 0.0264
ESR / 298
NH
H3C
CH3
O
Mg
O
N
H
00Ito
Landolt-Börnstein
New Series II/26A2
Ref. p. 329]
3 Radicals in metal complexes
69
Substance
Generation / Matrix or
g-Factor /
Solvent / Method / T [K] a-Value [mT]
Ref. /
add. Ref.
[C18H21BaNO3] •+
chemical reaction
2.0041
96Fer
acetate buffer, pH 5
ESR / RT
H(3): 0.0432
H(5): 0.3663
H(6): 0.0899
H(α1): 0.3200
H(α2): 0.3036
chemical reaction
2.0041
acetate buffer, pH 5
ESR / RT
H(3): 0.0350
H(5): 0.3768
H(6): 0.0830
H(α1): 0.3186
H(α2): 0.3116
chemical reaction
2.0043
acetate buffer, pH 5
ESR / RT
H(3): 0.0222
H(5): 0.3890
H(6): 0.0700
H(α1): 0.3489
H(α2): 0.3332
chemical reaction
2.0042
acetate buffer, pH 5
ESR / RT
H(3): 0.0392
H(5): 0.3715
H(6): 0.0872
H(α1): 0.3106
H(α2): 0.3062
chemical reaction
species 1, 43 %:
KCl / NaOH buffer
2.00468
•+
HO
H
N
O
CH3
O
Ba
[C18H21CaNO3] •+
•+
HO
H
N
O
CH3
O
Ca
[C18H21MgNO3] •+
•+
HO
H
N
O
Mg
O
CH3
[C18H21NO3Sr] •+
•+
HO
H
N
O
CH3
O
Sr
[C21H19CaN2O8] • or
[C21H20CaN2O8] •+
H3 C
O
N
CH3
OH
OH
O
O
O−
•2−
ESR / RT
Ca2+
CONH2
1
O
- H+ + H +
H3 C
O
N
CH3
OH
OH
CONH2
O
O
OH O
Landolt-Börnstein
New Series II/26A2
H(β): 0.589
H(β '): 0.162
H(8): 0.109
H(9): 0.308
species 2, 57 %:
2.00465
•−
Ca2+
2
H(β): 0.542
H(β '): 0.165
H(8): 0.120
H(9): 0.310
96Fer
96Fer
96Fer
91Nil
70
3.3 Complexes of group 2 (Be, Mg, Ca, Sr, Ba)
Substance
[C21H19N2O8Sr] •
H3C
O
• 2−
CH3
N
OH
O
O
O−
Ref. /
add. Ref.
autooxidation
91Nil
ESR / RT
H(β): 0.556
H(β '): 0.167
H(8): 0.130
H(9): 0.300
CONH2
•−
O
Me
Me
reduction with barium
metal
THF
Ba2+ ESR / ENDOR / 200
O
Me
Me
2.00466
O
[C22H22BaO4] •+
Me O
Generation / Matrix or
g-Factor /
Solvent / Method / T [K] a-Value [mT]
phosphate buffer, pH 12
Sr2+
OH
[Ref. p. 329
O
2.0049
90Boc
135,137
Ba: 0.145
H: 0.0097
H: < 0.005
Me
electrochemistry
[C25H42BaNO5] •2+
O
tBu
N
tBu
Ba2+
O
N
tBu
electrochemistry, UV-VIS, mass and resonance Raman
spectroscopy
Ca2+
O
N
tBu
O•
chemical oxidation
2.0043
acetonitrile
H: 0.677
01Ito
O
ESR / 233
O
electrochemistry, UV-VIS, mass and resonance Raman
spectroscopy
[C25H42MgNO5] •2+
tBu
H: 0.606
O
O
O•
acetonitrile
01Ito
ESR / 233
[C25H42CaNO5] •2+
tBu
2.0045
O
O
O•
chemical oxidation
chemical oxidation
2.0039
acetonitrile
H: 0.642
01Ito
O
Mg2+
O
ESR / 233
O
electrochemistry, UV-VIS, mass and resonance Raman
spectroscopy
Landolt-Börnstein
New Series II/26A2
Ref. p. 329]
3 Radicals in metal complexes
71
Substance
Generation / Matrix or
Solvent / Method / T [K]
g-Factor /
a-Value [mT]
Ref. /
add. Ref.
[C25H42SrNO5] •2+
chemical oxidation
2.0045
01Ito
acetonitrile
H: 0.749
O
tBu
O
tBu
ESR / 233
Sr 2+
N
O
O
O•
electrochemistry, UV-VIS, mass and resonance Raman spectroscopy
[C27H46BaNO6] •2+
tBu
O
tBu
N
O
Ba2+
O•
O
tBu
tBu
O
Ca2+
O•
O
tBu
N
O•
O
Mg
O
O
O
N
O
Landolt-Börnstein
New Series II/26A2
2.0042
acetonitrile
H: 0.677
01Ito
ESR / 233
chemical oxidation
2.0046
acetonitrile
H: 0.606
01Ito
ESR / 233
O
electrochemistry, UV-VIS, mass and resonance Raman spectroscopy
tBu
O•
chemical oxidation
2+
[C27H46SrNO6] •2+
tBu
ESR / 233
electrochemistry, UV-VIS, mass and resonance Raman spectroscopy
[C27H46MgNO6] •2+
tBu
H: 0.630
O
O
O
acetonitrile
01Ito
electrochemistry, UV-VIS, mass and resonance Raman spectroscopy
[C27H46CaNO6] •2+
N
2.0042
O
O
O
chemical oxidation
O
Sr 2+
O
chemical oxidation
2.0043
acetonitrile
H: 0.642
01Ito
ESR / 233
O
electrochemistry, UV-VIS, mass and resonance Raman spectroscopy
72
3.3 Complexes of group 2 (Be, Mg, Ca, Sr, Ba)
[Ref. p. 329
Substance
Generation / Matrix or
Solvent / Method / T [K]
g-Factor /
a-Value [mT]
Ref. /
add. Ref.
[C34H32Mg2N4] •+
chemical reaction
2.0035
95Sta1
dichloroethane or THF
14
•+
ESR / 293
Me
N(4 H): 0.24
H(6 H): 0.12
Mg
Ph N
N Ph
N
Me
N
Mg
Me
Me
[C44H8F20MgN4] • +
chemical oxidation
F
F
F
95Bar
dichloromethane
ESR / 298
F
F
F
F
•+
F
F
2.0037
N
Mg N
N
N
F
F
F
F
F
F
F
F
F
F
F
electrochemistry, UV-VIS and resonance Raman spectroscopy
[C44H20F8MgN4] • +
chemical oxidation
•+
F
N
Mg N
N
N
F
F
F
F
F
95Bar
dichloromethane
ESR / 298
F
F
2.0035
ESR / 183
14
dichloromethane /
methanol (5 %)
14
N: 0.110
N: 0.117
ESR / 298
electrochemistry, UV-VIS and resonance Raman spectroscopy
Landolt-Börnstein
New Series II/26A2
Ref. p. 329]
3 Radicals in metal complexes
73
Substance
Generation / Matrix or
Solvent / Method / T [K]
g-Factor /
a-Value [mT]
Ref. /
add. Ref.
[C44H28MgN4] • −
electrochemically generated
gav = 2.0024
94Set
[Mg(TPP)] • −
butyronitrile
aav = 0.093
ESR / 300
butyronitrile
ESR / 77
g⊥ = 2.0000
g|| = 2.0035
a⊥ = 0.057
a|| = 0.11
temperature data available from 10 K to 300 K
[C48H28Cl8MgN4O] • +
•+
O
Cl
gav = 1.998
dichloromethane or
acetonitrile / THF 9:1
g⊥ = 2.000
g|| = 1.994
ESR / 295
a⊥ = 0.143
a|| = 0.143
dichloromethane or
acetonitrile / THF 9:1
gav = 1.999
Cl
Cl
N
Mg N
N
N
Cl
electrochemically generated
Cl
Cl
Cl
ESR / 100
Cl
96Kal
g⊥ = 2.004, 1.999
g|| = 1.995
a⊥ = 0.041, 0.114
a|| = 0.143
[C48H48MgN8] •+
electrochemically generated
•+
tBu
tBu
N
N
tBu
2.0019
acetonitrile
ESR / 298
N
Mg N
N
N
N
N
Landolt-Börnstein
New Series II/26A2
tBu
electrochemistry, UV-VIS and NIR spectroscopy
89Fre
74
3.3 Complexes of group 2 (Be, Mg, Ca, Sr, Ba)
[Ref. p. 329
Substance
Generation / Matrix or
Solvent / Method / T [K]
g-Factor /
a-Value [mT]
Ref. /
add. Ref.
[C52H36Cl8MgN4O2] • +
electrochemically generated
gav = 1.999
96Kal
•+
dichloromethane or
acetonitrile / THF 9:1
O
ESR / 295
Cl
Cl
Cl
N
Mg N
N
N
Cl
Cl
ESR / 100
Cl
Cl
Cl
O
dichloromethane or
acetonitrile / THF 9:1
gav = 1.999
g⊥ = 2.003
g|| = 1.990
a⊥ = 0.027
a|| = 0.027
Landolt-Börnstein
New Series II/26A2