Alkali metal cations, energetics

By considering the stability constant and the lipophilicity of host molecules, Fyles et al. synthesized a series of carboxylic ionophores having a crown ether moiety and energetically developed the active transport of alkali metal cations 27-32). Ionophores 19-21 possess appropriate stability constants for K+ and show effective K+-selective transports (Fig. 5). Although all of the corresponding [15]crown-5 derivatives (22-24) selectively transport Na+, their transport rates are rather slow compared with... 

Lobacz et al. [52] have described partial adsorption ofTl+-cryptand (2,2,2) complex on mercury electrode. From voltocoulom-etry, cyclic voltammetry, and chrono-coulometry, it has been deduced that electroreduction of this complex proceeds via two parallel pathways from the solution and from the adsorbed states, which are energetically close. Also, Damaskin and coworkers [53] have studied adsorption of the complexes of alkali metal cations with cryptand (2,2,2) using differential capacity measurements and a stationary drop electrode. It has been found that these complexes exhibit strong adsorption properties. Novotny etal. [54] have studied interfacial activity and adsorptive accumulation of U02 " "-cupferron and UO2 - chloranilic acid complexes on mercury electrodes at various potentials in 0.1 M acetate buffer of pH 4.6 and 0.1 M NaCl04, respectively. 

Alkali Metal Cation-Cavitates Rigid, Macrospheroidal Multidentate, Multisite Zeolate Nanoreaction Chambers We have recently completed an extensive series of quantitative kinetic measurements in zeolite Y, for archetypical CO substitution reactions of Mo (CO) -M5 Y (M = Li, Na, K, Rb and Cs) by PMcj and CO. A key objective of this particular study was to evaluate how the energetics and dynamics of this reaction compared to the situation found in the gas and solution phases. Through such detailed studies of the rates of these reactions as a function of, for example, temperature, pressure, loading and cation type, it was anticipated that one could begin to identify the different ways in which the special environment found within the nanoreaction vessels of a zeolite host could influence the nature of chemical transformations contained therein. 

High-pressure mass spectrometry (HPMS) has largely been applied to the determination of bonding energetics in adducts (also called clusters when several ligands are bonded to one cation) of alkali metal cations with simple molecules [105, 106]. 

Fast atom bombardment directs a beam of energetic inert-gas atoms onto a sample in a viscous liquid matrix, usually in glycerol or triethanolamine. A flow of the sample in the solution replenishes the sample on the surface and limits degradation by the particle beam. The surfactant suppresses ionization of glycerol, and by providing a cleaner background, it increases the sensitivity of the FAB method [90,91]. The FAB techniques usually provide quasimolecular ions with only a few fragment ions. Electrolytes added to the sample solution facilitate the formation of quasimolecular ions, for example, adduct ions with alkali metal cations. 

Apart from the ammonium salt of dinitramidic acid, many different stable oxygen-rich salts with a variety of cations are possible which could provide a new class of energetic materials. The presence of -N(N02)2 groups in these compounds imparts high heat of formation, density and oxygen balance and hence has received a lot of attention in recent years. The alkali metal dinitramide... 

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