A B S TRAC T The cation selectivity of the Na entry mechanism located in the outer membrane of the bullfrog (Rana catesbeiana) skin epithelium was studied. This selectivity was determined by measuring the short-circuit current when all of the external sodium was replaced by another cation and, also, by noting the relative degree of inhibition that the alkali metal cations produced on Na influx....

Bond-length distributions have been examined for 55 configurations of alkali-metal ions and 29 configurations of alkaline-earth-metal ions bonded to oxygen, for 4859 coordination polyhedra and 38 594 bond distances (alkali metals), and for 3038 coordination polyhedra and 24 487 bond distances (alkaline-earth metals). Bond lengths generally show a positively skewed Gaussian distribution that ori...

Because of contradictions in the literature, we reinvestigated the kinetics of the Birch reduction, i.e. the hydrogenation of benzene and its derivatives in metal ammonia solutions (MAS; containing solvated electrons e and metal cations M) with alcohols to yield the corresponding cyclohexa-1,4-dien compounds (e.g. 2Li+ 2CH3OH+C6H6)2CH3OLi+C6H8). The kinetics of this reaction are obscured since ...

Aspects of host-guest complexation are examined in the solvent-free environment of a mass spectrometer. A kinetic dissociation method is used to determine orders of relative ammonium and alkali metal cation binding affinities of an array of model hosts, such as crown ethers and their acyclic analogs. Sizeselective effects on binding are observed from these gas-phase experiments. The binding pro...

Monte Carlo simulations were employed to gain insight on HCN adsorption mechanism on LTA zeolites with different alkali metal cations, Li, Na, and K. Adsorption isotherms were calculated at four different temperatures at and above the normal boiling point of HCN. Results show that adsorption capacity depends on the type of the extraframework cation and Li-LTA showed the highest HCN adsorption c...

Rubidium ytterbium(III) tetra-kis-(polyphosphate), RbYb(PO3)4, was synthesized by solid-state reaction. It adopts structure type IV of the MRE(PO3)4 (M = alkali metal and RE = rare earth metal) family of compounds. The structure is composed of a three-dimensional framework made up from double spiral polyphosphate chains parallel to [10-1] and irregular [YbO8] polyhedra. There are eight PO4 tetr...

This work demonstrates by means of DFT and ab initio calculations that recognition of alkali cations can be achieved by probing the variations of the second-order nonlinear optical properties along the commutation process in spiropyran/merocyanine systems. Due to the ability of the merocyanine isomer to complex metal cations, the switching between the two forms is accompanied by large contrasts...

Electrostatics are central to all aspects of nucleic acid behavior, including their folding, condensation, and binding to other molecules, and the energetics of these processes are profoundly influenced by the ion atmosphere that surrounds nucleic acids. Given the highly complex and dynamic nature of the ion atmosphere, understanding its properties and effects will require synergy between compu...