Attempts to separate contact and pseudocontact shifts

The procedure based on the direct use of the g tensor anisotropy and Eq. (2.24) is quite common for S = xh systems, since g values from frozen solutions are easily obtainable. In this case, both the second order Zeeman contributions and possibly the effects of temperature on the g values are neglected. Furthermore, the directions of the molecular axes are arbitrarily assumed unless single-crystal data are available. Attempts are available in the literature regarding low spin cobalt(II) [77] and copper(II) [61]. 

Other semiquantitative methods for evaluating the metal-centered pseudocontact contributions to the shifts are based on the pattern predicted for a series of metal ions of the pseudocontact shifts assuming axial symmetry. Eq. (2.18), which 

2 The diamagnetic contribution, if not negligible, should be appropriately subtracted. 

Particular cases applicable to low spin and high spin Fe(III) will be discussed in Section 5.2. The case of lanthanides will be discussed in Section 2.8.4. 

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