Stability constants calculate

The conditional stability constants calculated for the different salinity ranges are given in Table 5. It looks as if in the more saline samples complexes with lower K are formed. 

Equation (f) allows for electron transfer over a range of separation distances and is appropriate when most of the reaction occurs at separation distances between r and (r -1-6r). Because 5r is typically 0.8 A (80 pm), for many systems r/3 s Sr, and the values of the stability constant calculated from Eqs. (e) and (f) do not differ appreciably. 

Table 5.21 illustrates dramatic difference (almost eight decades per one proton released) in the stability constant calculated for different number of protons released per one adsorbed Pb assumed in the model calculations. The effect of the assumed electrostatic position of Pb is less significant, namely, only one order of magnitude in the stabihty constant between the inner and outer sphere complex. It should be emphasized that all these results were calculated using the same model for primary surface charging (one set of TLM parametei-s). Table 5,21 illustrates how limited is... 

Also for other diffuse layer models (cf. Table 5.13) the calculated stability constant of silica-Pb surface complex is considerably higher than for their TLM counterparts obtained from the same experimental data. The difference between the highest and the lowest K in Table 5.28 by almost two orders of magnitude is more significant than the discrepancies between the stability constants calculated for different diffuse layer models obtained for alumina (cf. Table 5.22). In spite of different K, the course of the calculated uptake curves obtained for different diffuse layer models and one proton released per one adsorbed Pb with... 

IDespite these difficulties, approximate stability constants, calculated for 1 1 complexes, are useful, because they allow comparison of the com-plexing ability of various cations and various polyols, and they enable the calculation of the approximate extent of complex-formation at different concentrations. 

It is recommended that the recalculated values be included in the review the magnitude of the uncertainty values are such that they would account for the correction of the data to 25°C. Overall, there was little difference between the stability constants calculated by the authors and those determined in the present review. 

Pt acetylenes can also function as fluoresecent sensors for cations. Receptor 45 incorporates two 4-ethynylbenzo-15-crown-5 moieties with luminescent dimino Pt(ii) complexes.In acetonitrile solution, complex 45 is weakly emissive (excitation at 405 nm, Amax = 635, 0= 1.1 x 10 ). However, on addition of significant increase in the emission intensity and a blue shift in A ax to 555 nm were observed. At 40equiv. of Mg or Zn, the measured enhancement was 1,035- and 870-fold, respectively. Other cations, namely, K, Na, and Gd, resulted in a less than 10-fold emission enhancement. The binding stoichiometry was found to be 1 2 receptor cation, and the overall stability constants calculated for Na, Mg, and Zn were [3 = 7.9 x 10, 5.3 x 10, and 9.3 x 10 respectively. 

The binding of several RuCp compounds to HSA was studied as a first approach to outline its pharmacokinetics and had been investigated by spectroscopic methods (absorption and fluorescence) and ultraflltration-UV-vis. as weU. It was found that TM34 binds to HSA forming a 1 1 adduct the stability constant calculated for this HSA-TM34 adduct was log Kb = 4. This value is similar to that found for KP1019 and shows that the complex can be transported in the blood by HSA [11],... 

It is inferesting to note, however, that the stability constants calculated on the basis of different models and different techniques deviate very little. As an example, the association constant for [Eu(N03)] " at / = 0.5M NaC104 may be quoted as... 

The value derived by Neck and Kim (2001) from available data at that time was log 4 = -10.0 1.4, consistent with the stability constant calculated in the present review. 

The Zr4(OH)25" species was postulated by Veyland (1999) to describe solubility and potentiometric data. In an earlier publication, however, the author used the species Zr2(OH)7" to describe the same data (Veyland et al., 1998). The Zr4(OH)45 species was used by Brown, Curti and Grambow (2005) to describe the solubility data from a number of studies (Kovalenko and Bagdasarov, 1961 Bilinski, Branica and Sillen, 1966 Veyland, 1999). However, the solubility measured in these studies was overestimated due to the presence of colloids which were not adequately removed from the experimental solutions. As such, hydrolysis species and their associated stability constants derived from these data cannot be reliable. Recently, Altmaier, Neck and Fanghanel (2008) showed conclusively that neither their data nor that of Sasaki et al. (2006) could be described with the inclusion of the Zr4(OH)45 species, with a solubility almost three orders of magnitude higher predicted with the inclusion of the species than was measured. Consequently, neither the Zr4(OH)45 nor the Zr4(OH)j5(aq) species or stability constants calculated for them are retained in this review. 

Available and reinterpreted data for the monomeric hydrolysis species of zir-conium(IV) are given in Table 10.6. As indicated, a number of the published data have been reinterpreted and in some cases the stability constants calculated in the present review are considerably different from those derived in the original study. Detail of the reinterpretations made in this review is provided in the following or, if such reinterpretations have been made previously and accepted in the present review, a citation to the accepted reinterpretation is given. 

There are only three values which appear to be consistent with the stability constant derived by Neck and Kim (2001) for Th(OH)3 at 25°C and zero ionic strength, that is, log 3° =-11.0 1.0. Rand et al. (2007) calculated stability constants at zero ionic strength from those given by Kiciak and Stefanowicz (1971), Ekberg et /. (2000) and Bentouhami etal. (2004) of log 3 = -10.4 0.2, -11.8 3.0 and -10.3 0.1, respectively. These values are within the uncertainty of the stability constant calculated by Neck and Kim (2001), and this value is retained in the present review ... 

From the stability constant calculated for zero ionic strength in perchlorate media and the single datum for the Th4(OH)8 species given for chloride media (Hietanen and Sillen, 1968), the ion interaction coefficient that has been determined assuming a linear relationship with ionic strength (i.e. Ac2 =0) is... 

Gamsjager and Beutler (1979) reported data for the second stepwise stability constant for Ir(OH)2. These can be combined with the data for 0 to determine the constant for 02- The stability constants calculated in this manner (log 02, 1.05 mol kg-i NaClOJ are -10.41, -9.86, -9.57 and -9.21 at 5, 15, 25 and 35 "C, respectively. From these stability constants, those relevant to zero ionic strength (log 02°) were —9.35, —8.77, —8.46 and —8.07, respectively. These data... 

The stability constant calculated for zero ionic strength is in good agreement with that selected by Baes and Mesmer (1976) (log 22 — O- )-... 

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