NMRD profiles

Aime, S., Anelli, P.L., Botta, M., Fedeli, F., Grandi, M., Paoli, P., and Uggeri, F. (1992) Synthesis, characterization, and 1/T1 NMRD profiles of gadolinium (III) complexes of monoamide derivatives of DOTA-like ligands. X-ray structure of the 10-[2-[[2-hydroxy-l-(hydroxyl-methyl)ethyl]amino]-l-[phenylmethoxy)methyl]-2-oxo-ethyl]-l,4,7,10-tetraaza-cyclododecane-l,4,7-triacetic acid-gadolinium (III) complex. Inorg. Chem. 31, 2422-2428. 

H NMRD Profiles of Paramagnetic Complexes and Metalloproteins Ivano Bertini, Claudia Luchinat and Giacomo Parigi... 

The lattice dynamics in this model depends on a larger number of parameters. Except for the magnetic field, we have the magnitudes of the static and transient ZFS and the two correlation times, xp and x. The model is very flexible and can predict NMRD profiles of widely different shapes, exemplified in Fig. 5. 

Fig. 5. NMRD profiles for an asymmetric complex calculated for different values of the transient ZFS. Reproduced with permission from Larsson, T Westlund, P.O. Kowalewski, J. Koenig, S.H. J. Chem. Phys. 1994, 101, 1116-1128. Copyright 1994 American Institute of Physics.

Fig. 7. NMRD profiles calculated for slightly asymmetric, weakly deformable complexes with different electron spin quantum numbers (a) cylindrically-symmetric ZFS, E = 0 (b) maximum rhombicity E = DjS. Reprinted from J. Magn. Reson. vol. 146, Nilsson, T. Kowalewski, J., Slow-motion theory of nuclear spin relaxation in paramagnetic low-symmetry complexes A generalization to high electron spin , pp. 345-358, Copyright 2000, with permission from Elsevier.

Fig. 9. Fit of the slow-motion theory to the experimental NMRD profile for Ni(tmc)(H20). Reprinted with permission from Nilsson, T Parigi, G. Kowalewski, J. J. Phys. Chem. 2002,106,4476-4488. Copyright 2002 American Chemical Society.

The modified Florence program is well-suited for fitting the experimental NMRD profiles for slowly-rotating complexes of gadolinium(HI), an S = 7/2 ion characterized by relatively low ZFS, whose electron spin relaxation can be considered to be in the Redfield limit. An example of fitting an NMRD profile for aqueous protons, using different methods, for a protein adduct of a Gd(HI) chelate capable of accommodating one water molecule in the first coordination sphere, is displayed in Fig. 11. Other examples will be provided in Chapter 3. 

Fig. 10. Calculated NMRD profiles for S = 1 for a given parameter set and different theoretical approaches. Solid line slow motion theory dotted line original Florence model dashed line modified Florence model dotted-dashed line SBM. Reproduced with permission from Bertini, L Kowalewski, J. Luchinat, C. Nilsson, T Parigi, G. J. Chem. Phys. 1999, 111, 5795-5807. Copjn ight 1999 American Institute of Physics.

Fig. 11. Experimental NMRD profile for GdDOTA(BOM)3-BSA in aqueous solution and the least squares fits obtained using the modified Florence approach (solid line), original Florence model (dashed-dotted line) and the SBM (dashed line). From Kruk, D. Nilsson, T. Kowalewski, J. Phys. Chem. Chem. Phys. 2001, 5, 4907-4917. Reproduced by permission of the PCCP Owner Societies.

Fig. 12. Experimental and calculated NMRD profiles for GdEDTA in aqueous solution in the presence (upper curve) and absence (lower curve) of bovine serum albumin. Reprinted from J. Magn. Reson. vol. 162, Kruk, D. Kowalewski, J., Nuclear Spin Relaxation in Paramagnetic Systems (S > 1) under Fast Rotation Conditions , pp. 229-240, Copyright 2003, with permission from Elsevier.

Abernathy and Sharp (130,145) treated the intermediate regime, when the reorientation of the paramagnetic species is in-between the slow- and fast-rotations limits. They applied the spin-dynamics method, described in Section VI, to the case of outer-sphere relaxation and interpreted NMRD profiles for non-aqueous solvents in the presence of complexes of Ni(II) (S = 1) and Mn(III) (S = 2). 

Fig. 18. NMRD profile for Gd(III)(Cn-DOTP) -HSA calculated using the radial distribution function of Fig. 17. Reproduced with permission from Kruk, D. Kowalewski, J. J. Chem. Phys. 2002, 117,1194-1200. Copyright 2002 American Institute of Physics.

I. From the NMRD profile to the electron relaxation mechanism 105... 

A. Dependence of the NMRD profiles on the electron relaxation parameters 106... 

I. From the NMRD Profile to the Electron Relaxation Mechanism... 

Let us first examine the NMRD profiles of systems with correlation times Xci = Tie assuming the Solomon-Bloembergen-Morgan (SBM) theory (see Section II.B of Chapter 2) (2-5) is valid, and in the absence of contact relaxation. We report here the relevant equations for readers ... 

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