Cations strontium

Fialkiewicz and Szandorowski examined the penetration of Sr and Cl ions through air-dried films of a styrenated alkyd pigmented with iron oxide over the range 10-60% p.v.c. (pigment volume concentration) and found intense penetration of the strontium cations, but negligible penetration of the chloride ions. 

Another related host-guest complex has been constructed from citric acid, boric acid, and a strontium salt in a 2 1 1 stoichiometry. In this complex the strontium cation is surrounded by four water molecules, two monodentate carboxyl groups and one oxygen atom of the BO4 unit [161]. 

Solov ev, V.P., Kireeva, N.V., Tsivadze, A.Yu., Varnek, A. 2006. Structure-property modeling of complexation of strontium cation by organic ligands. J. Struct. Chem. 47 311-325. 

The far-IR spectra of hydrated and dehydrated SrA are displayed in Figure 10. The form of the spectra aside from red shifts are remarkably similar to those of the Ca-A described above. This is not surprising as the siting and populations of Sr2+ ions are identical to Ca2+ in Ca -A (19b). The Sr2+ ions are located in the six-rings, with 4.5 ions per pseudo-cell in site B, and 1.2 ions per pseudo-cell in site C. Together the Ca2+ and Sr2+ zeolites yield a consistent picture of the divalent cation far-IR vibrational frequencies, and are useful models for the investigation of the transition metal (2+) -A systems. Strontium cation vibrations anticipated to occur at 175 cm-l (site B) and at 145 cm (site C) compare quite well with the observed bands at 182 and 142 cm l respectively. 

Fig. 3.16 Mo (green) surrounded by six next-uearest-neighbOT Mg (red) in a perfectly B-sile ordtued material oxygen ions are white and strontium cations are mnitled fm clarity (Reprinted in part with permission from [80]. Copyright 2007 American Chcanical Society)...

In this communication our attempts to exploit the electrolysis at ITIES for analytical purposes are described. As examples the determination of acetylcholine, tetraethylammonium, calcium, barium and strontium cations by differential pulse stripping voltammetry (DPSV) at the hanging electrolyte drop electrode (HEDE) will be presented. 

The determination of calcium, barium and strontium cations is an example of the ionophore (X) facilitated charge transfer process... 

Even though the stability constants for calcium, barium and strontium cations in nitrobenzene are much higher than that for lithium cation, the translocation of lithium ion from water to nitrobenzene is shifted by about 300 mV negatively when it is used as a base electrolyte, i.e., when [Li+(w)]>>[X(n)] and it coincides with the transfer of alkaline earth metal cation. From a comparison of the standard electrical potential difference and from the calculated half-wave potentials using the stability constant for several cations we have chosen magnesium chloride as a base electrolyte for the aqueous phase. To minimize the base electrolytes current in DPSV we have decreased their concentrations. In the case of magnesium chloride it was 2.5 mM solution in water and 5 mM solution of TBATPB in nitrobenzene. The concentration of the ionophore was 1 mM. 

Table 8.3 presents reaction rate constants for Sr" " reacting with several small neutral oxygen-containing reagents. The strontium cation has electronic configuration [Kr] 5s and electronic state term symbol S. The fastest Sr+ reaction studied in our lab is, by far, that with nitrogen... 

Table 8.3 Selected properties of reactant neutrals and reaction rate coefficients for reactions with strontium cations (Sr+, S) ...

Mackova, J., and Mikulaj, V. (1996). Transport of strontium cation through a hollow fiber supported dichlorobenzene membrane using 18-C-6 crown ether. Nitrate and anion of dinonylnaphfhalene sulfonic acid. J. Radioanal. Nucl. Chem. 208, 111. 

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