Table 3 Relaxation parameters from the global analysis of 1H NMRD and 17O NMR dataa

From: Design of Mn(1,4-DO2A) derivatives as stable and inert contrast agents for magnetic resonance imaging

Parameters

Mn(1,4-Et4DO2A)

Mn(L1)

Mn(L2)

Mn(1,4-DO2A)b

20r1/mM−1 s−1

3.1

2.8

2.5

2.10

Δ2/1019 s−2

4.7 ± 0.6

22.2 ± 2.1

19.2 ± 1.1

48.1

τv/ps

26 ± 2

10 ± 1

8 ± 1

4.4

τM/ns

0.59 ± 0.07

0.97 ± 0.12

0.77 ± 0.11

0.88

ΔHM#/kJ mol−1

28.0 ± 1.5

29.0 ± 1.2

29.0 ± 2.0

29.4

τR/ps

63 ± 2

64 ± 1

81 ± 3

46

AO/ℏ/106rad s−1

39.7 ± 1.1

43.8 ± 1.5

45.0 ± 2.1

43.0

q

1c

0.9 ± 0.1

0.5 ± 0.1

0.87

  1. aThe following parameters were fixed to standard values: rMn-H = 2.83 Å, the relative diffusion coefficients of the solute and solvent at 283, 298, and 310 K (D = 1.30, 2.24 and 3.10 × 10−5 cm2 s−1, respectively), the associated activation energy (ED = 20.0 kJ mol−1), and the distance of closest approach (a = 3.6 Å) between the solute and the water molecules in the outer coordination sphere.
  2. bFrom ref. 14.
  3. cFixed in the fitting procedure.
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