Cesium binding

K = 63 M 1, Kb = 1.4M-1)47 lithium-7 (K = 14 M 1 K" = 0.5 M 1) 49) and for cesium-133 (K, st 50 M-1, K = 4M 1)S0). In the case of sodium-23, transverse relaxation times could also be utilized to determine off-rate constants k ff = 3 x 105/sec k"ff = 2x 107/sec47,51). Therefore for sodium ion four of the five rate constants have been independently determined. What has not been obtained for sodium ion is the rate constant for the central barrier, kcb. By means of dielectric relaxation studies a rate constant considered to be for passage over the central barrier, i.e. for jumping between sites, has been determined for Tl+ to be approximately 4 x 106/sec 52). If we make the assumption that the binding process functions as a normalization of free energies, recognize that the contribution of the lipid to the central barrier is independent of the ion and note that the channel is quite uniform, then it is reasonable to utilize the value of 4x 106/sec for the sodium ion. 

C07-0053. Draw energy level diagrams that illustrate the difference in electron binding energy between cesium metal and chromium metal. Refer to Problems and. ... 

C22-0040. Use atomic masses to compute the total binding energy and the binding energy per nucleon for elemental cesium, which has just one stable nuclide. 

Rodrigues, G.C., Ourdane, M.A., Bieron, J., Indelicato, P. and Lindroth, E. (2001) Relativistic and many-body effects on total binding energies of cesium ions. Physical Review A, 63, 012510-1-012510-10. 

The increase in Tc depended on metal ions, as shown in Fig. 5. A large temperature increase was observed for potassium chloride, while the increase was only 1.5 °C for sodium chloride. The temperature increase was not observed by the addition of lithium and cesium chlorides. The binding affinity of a crown ether with metal ions depends on the cavity size [16]. When the ion diameter fits in the cavity size, the ion is captured by the crown ether. The cavity size of benzo[18]crown-6 is known to accommodate the diameter of K+ [17]. The relative Tc increase correlates well with the binding affinity of benzo[18]crown-6 to metal ions. K+ which efficiently binds to pendant benzo[18]crown-6 most pronouncedly increased Tc, while Li+ and Cs+ which are hardly captured by the crown ether groups could not increase Tc. 

The formation of the polynucleotide structure poly(I) is strikingly cation dependent, and relates to the size of the alkali metal cation in the central cavity. Lithium and cesium cations are too small or too large respectively to bind effectively. Na+ occupies a site that is 2.2 A away from four carbonyl oxygens, while K+ is able to occupy a site 2.8 A away from eight carbonyl oxygens.101... 

There is full agreement between the extraction and the complexation data, in that among the conformationally mobile 1,3-dimethoxy compounds, the crown-5 exhibits selectivity for potassium,31 the crown-7 is completely unselective and quite inefficient, whereas MC2 and MCI show selectivity for cesium. Interestingly, all ligands in the 1,3-alternate conformation display significant enhancement in the binding of... 

For the three conformers, the binding sequence is Na > K > Rb > Cs. This is supported by energy component analysis on the trajectories, as well as by Free energy perturbation (FEP) calculations. Intrinsically, Cs+ has the weakest interactions with both hosts. The largest contribution of the cation/host interaction energy comes from the ether ring rather than from the aromatic moieties. Each complex displays a clear conformational preference. Sodium is most stable in the cone conformation, whereas cesium is most stable in the 1,3-altemate conformation. 

MD simulations performed on calix[4]arene-monocrown-6 and on calix[4]arene-bis-crown-6 and their alkali complexes, suggested that incorporation of aromatic groups in the crown ether loop was a possible way to enhance cation binding and cesium over sodium selectivity.45... 

Table I lists the binding energies for the major constituent elements present on the mineral surfaces, both before and after reaction. These values are, in general, in good agreement with literature values for aluminosilicates (5). The value for Cs corresponds to that for ionic Cs salts. No large shifts are expected in these numbers, since there is no oxidation state difference between reactants and products. A detailed XPS study of the interaction of cesium (and strontium) with feldspar surfaces is in progress, and will be the subject of a future paper ...

Table I. Elemental Binding Energies (eV)a for Feldspars (i) Before and (ii) After Hydrothermal Reaction with Aqueous Cesium Solutions ...

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