Ligand held strength

In the case of mixed ligands photoreactivity may be predicted empirically from considerations of the ligand field strength (Adamson s rule). For O/, complex, the axis having the weakest average held as determined by the position of its respective ligands in the spectroehemical series will... 

It can be seen from the above discussion that the varying structural modes present in Figure 14 are readily available. For the partially encapsulated complexes there is not only a dependence upon the cation cavity best fit but also on the relative strengths of the competing counter donors, both anions and/or solvent molecules. This is shown in the structures of (79)NaI H20, where the water is held by the metal rather than the I-,402 and (72)NaBr-H20, where the sodium is either symmetrically coordinated with two H20 in axial positions, or non-symmetrically coordinated and lying out of the ligand plane towards the Br not the H20 (Figure 19).421... 

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