title: The nature of metal-ligand bonding in the primary hydration shell and in ionophores with alkali metal ions.
abstract: 1. Trasport of alkali ions in model membranes mediated by ionophores is associated with at least two basic problems: (a) a conceivable physical model for the metal-ligand bonding in the primary hydration shell and (b) migration of ions from the primary hydration shell to ionophores to form ion complexes. 2. The nature of metal-ligand bonding both in the primary hydration shell and in the ionophores has been found to be around 80% ionic and 20% covalent in both cases by indepdnent investigation. Clearly the energetics being equivalent in both systems, ions will not migrate from the former to the latter. 3. A novel model is proposed in terms of hydrogen bonding in the primary hydration shell for Li+ and Na+ so that the migration of these ions to ionophores is easily envisaged. Hydrogen bonding contribures 18% and 5% of the energy to the total hydration shell energy of Li+ and Na+, respectively.
mesh_terms: D000081:Acetamides; D001665:Binding Sites; D002151:Calorimetry; D002414:Cations, Monovalent; D005559:Formamides; D008024:Ligands; D008094:Lithium; D013058:Mass Spectrometry; D008567:Membranes, Artificial; D008954:Models, Biological; D008958:Models, Molecular; D008968:Molecular Conformation; D012964:Sodium; D013816:Thermodynamics; D014867:Water
chemical_list: D000081:Acetamides; D002414:Cations, Monovalent; D005559:Formamides; D008024:Ligands; D008567:Membranes, Artificial; D014867:Water; D008094:Lithium; D012964:Sodium