Abstract
<p> Formation constants for yttrium and rare earth element (YREE) chloride complexation have been measured at 25°C by examining the influence of medium (NaClO <sub> 4 </sub> and NaCl) on YREE complexation by fluoride ions and methyliminodiacetate (MIDA). YREE chloride complexation constants <sub> Cl </sub> β <sub> 1 </sub> ( <em> M </em> ) obtained in this work using dissimilar procedures are in good agreement and indicate that, at constant temperature and ionic strength, <sub> Cl </sub> β <sub> 1 </sub> ( <em> M </em> ) does not vary significantly across the fifteen-member series of elements. The ionic strength μ dependence of YREE chloride formation constants between 0 and 6 molar ionic strength can be written, for all YREE, as logCIβ1(M)=logCI⁡β10(M)−3.066μ0.5/(1+1.727μ0.5)">logCIβ1(M)=logCIβ01(M)−3.066μ0.5/(1+1.727μ0.5)logCIβ1(M)=logCI⁡β10(M)−3.066μ0.5/(1+1.727μ0.5)</p><p> where <sub> Cl </sub> β <sub> 1 </sub> ( <em> M </em> ) = [MCl <sup> 2+ </sup> ][M <sup> 3+ </sup> ] <sup> −1 </sup> [Cl <sup> −1 </sup> ] <sup> −1 </sup> and log <sub> Cl </sub> β <sub> 1 </sub> <sup> o </sup> ( <em> M </em> ) represents the MCl <sup> 2+ </sup> formation constant for all YREE at zero ionic strength: log <sub> Cl </sub> β <sub> 1 </sub> <sup> o </sup> = 0.65 ± 0.05.</p>
Original language | American English |
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Journal | Journal of Solution Chemistry |
Volume | 30 |
DOIs | |
State | Published - Jan 1 2001 |
Keywords
- rare earth elements
- complexation
- chloride
- stability constants
- ionic strength
- lanthanide
- yttrium
- MIDA
Disciplines
- Life Sciences