the do1(18c6)fi (mwli. na. k and i 8c6=18-crown-6) complexes have been chosen as the model systems toinvestigate the nature of chemical bonds between alkali metal cations and large mffitidentaie orgmnic ligands.the b3lyp/6-3i+g(d,p) level of calculation has been used for obtaining equilibrium geernetnes and p(r)functions (electron density distributions). by the aid of fundamental physical theor...

Complexes of the anion of the secondary amine 2-phenylaminopyridine (LH) with the heavier alkali metals Na-Cs have been prepared in the presence of various macrocyclic polyether crowns [12-crown-4 (12C4), 15-crown-5 (15C5), and 18-crown-6 (18C6)], which coordinate to the metal ions in all cases. Depending on the combination of alkali metal and crown, the products include separated ion pairs [(c...

Binding of metal cations to the nucleobases can influence base pairing, base stacking and nucleobase tautomerism. Gas-phase condensation of dc discharge generated alkali metal cations and thermally vaporized cytosine (DC/FT) has been found to produce kinetically trapped excited tautomeric conformations of the M(+)(cytosine) complexes, which influences the threshold collision-induced dissociatio...

Abstract The regulation of anions and cations at the atomic scale is great significance in membrane-based separation technologies. Ionic transport techniques could also play a crucial role developing high-performance alkali metal batteries such as metal-sulfur metal-selenium batteries, which suffer from non-uniform ions (e.g., Li + or Na ) detrimental shuttling effect polysulfide/polyselenide a...

The selectivity of acetylcholine (A-Ch)-activated channels for alkali cations, organic cations, and nonelectrolytes in cultured muscle cells has been studied. To test the effect of size, charge, and hydrogen-binding capacity of permeant molecules on their permeability, we have obtained the selectivity sequences of alkali cations, compared the permeability of pairs of permeant molecules with sim...

Abstract The average composition of natural waters such as rivers, lakes, ocean, and hydrothermal vents and corresponding solids in equilibrium (e.g., river-suspended particles or shale; lake sediments; oceanic pelagic clay, organisms, and manganese nodules; and the mid-ocean ridge basalts) do not change randomly. The observed positive correlation between the electron binding energy (Iz [*Iz]) ...

a new series of noncyclic ionophores containing two to four furan units (ia to iiib) i.e. 1,1-difurylethane (ia), 2,5-bis(methylfurfuryl)furan (iia) and 1,1’ ethyledenebis[5-(methylfurfuryl)furan] (iiia), 2,2-difurylpropane (ib), 2,5-bis (dimethylfurfuryl)furan(iib), 2,2’-isopropylidenebis[5-(dimethylfurfuryl)furan] (iiib) have been synthesized by the condensation of furan with acetaldehyde and...