NMR of metal ligands

Consider a metal complex CM, where C is a multidentate ligand that leaves an empty coordination position on the metal, in the presence of a monodentate ligand L. CM could also be a metalloenzyme interacting with a substrate or an inhibitor L. The paramagnetic effects observed on a nucleus of L can then be used to obtain information on its dissociation constant  

Under fast exchange conditions, the molar fraction of bound ligand /m can be expressed in terms of Eqs. (4.13) and (4.31) as 

If the experimental conditions are such that [CML] is always much smaller than Cl (i.e. large excess of L with respect to CM), then Eq. (4.31) becomes 

like Eq. (4.32), is valid when the ligand is in fast exchange it is also valid under the exchange-limited conditions, which are described in Eqs. (4.8), (4.10) and (4.11), as long as xm is not dependent on Cl- In this case, K can still be obtained, in addition to the limit values of flip, / 2P, or A wp at /a/ = 1. 

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