Group I ions

While often somewhat ignored by coordination chemists, the interaction of Group I ions has recently received increased attention, particularly with regard to duplex DNA. To a large extent these ions are involved in charge neutralization of the anionic backbone of (deoxy)-ribonucleotide polymers. However, more specific effects have been... 

The lack of structural detail for interactions involving labile metals, particularly the Group I ions, is problematic and here model compounds are proving useful. A range of binding modes for Na+ and K+ ions involving both T-02 and T-04 have been realized with Nl-alkylated thymi-... 

The nature of adsorption of Group I ions on the oxide is illustrated in Figure 1 in which the adsorption isotherms for potassium ions on Mn02 are given as a function of pH. Similar behavior was observed for the adsorption of sodium ions. 

The group I ions are predicted to precipitate as insoluble chlorides, as indicated in the following equations ... 

In both of the above examples, we used an anionic buffer (MOPS or cacodylate). The buffer anions have only repulsive interactions with RNA and can be grouped with chloride ions when calculating mean ion activities. Thus, we apply mean ionic activity coefficients measured with KC1 solutions to solutions in which K+ ions are contributed both by KC1 and K-buffer salts. We strongly advise against the use of cationic buffers such as Tris, because of its idiosyncratic interactions with nucleic acids as compared to group I ions, and particularly against mixing KC1 with Tris buffer, which creates a cationic mixture of unknown activity. 

Hydrogen, ammonium, and Group I ions form soluble compounds with all negative ions. 

Group I ions, hydrogen ions, and ammonium ions always form soluble ionic compounds.)... 

The separation of the Group I ions in the classic scheme of qualitative analysis. 

The treatment of the Group I ions is summarized in Fig. 8.14. Note that the presence of Pb2+ is confirmed by adding Cr042-, which forms bright yellow lead(II) chromate (PbCr04). Also note that H+ added to a solution containing Ag(NH3)2+ and Cl- reacts with the NH3 to form NH4+, thus destroying the Ag(NH3)2+ complex. Silver chloride then re-forms ... 

It is pertinent that there are other ions that have chemical behavior closely resembling that of the Group I ions ... 

TABLE 6-2 Data on Hydration of Aqueous Group I Ions ... 

The treatment of the Group I ions is summarized in Fig. 16.3. Note that the presence of Pb is confirmed by adding Cr04 , which forms bright yellow lead(ll) chromate... 

Polymer electrolytes incorporating an IL can be classified into two main groups (i) ion gels whereby the IL is the main conducting medium and the polymer is the support and (ii) polyelectrolytes prepared via the... 

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