Porous inorganic capsules in action: modelling transmembrane cation-transport parameter-dependence based on water as vehicle

Insight into basic principles of cation transport through ''molecular channels'', and especially details of the related fundamental H2O vehicle function, could be obtained via Li-7 NMR studies of the Li+ uptake/release processes by the unique porous nanocapsule [{(Mo-VI)(Mo5O21)-O-VI(H2O)(6)}(12) {(Mo2O4)-O-V(SO4)}(30)](72-) which behaves as a semi-permeable inorganic membrane open for H2O and small cations; channel traffic as well as internal cavity distribution processes show a strong dependence on ''environmental'' effects such as exerted by solvent properties, the amount of water present, and competing complexing ligands, and end up in a complex equilibrium situation as in biological leak channels.