Water exchange on main group and d-transition metal ions

Water Exchange on Main Group and d-Transition Metal Ions 

There are only few main group metal ion hydrates open to detailed mechanistic study of water exchange by NMR Be , Mg , Al , Ga and to a less extent, In . They provide the opportunity to study the influence of size and charge on exchange rate constant and mechanism without the complicating effects of the variation of the electronic occupancy of the d-orbitals. All of the alkali ions as well as Ca , Sr, and Ba are very labile as a consequence of their relatively low surface charge density. However, indications on water exchange on Sr can be obtained from 

The larger Mg ion is hexa-coordinated. The water exchange rate for [Mg(H20)6] (40) lies between those of the d-transition metals [Co(H20)6] + and [Ni(H20)e] + (Tables I and Table II), and reflects the order of ionic radii of these three ions. The measured activation volume is 

Rate Constants and Activation Parameters eor Water Exchange on Divalent First Row Transition Metae Ions [M(H20)s] + 

Rate Constants and Activation Parameters for Water Exchange on Trivalent First Row Transition Metal Ions [M(H20)6]  

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Water exchange on main group and d-transition metal ions... 

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