A TRLFS study on the complexation of Cm(III) and Eu(III) with 4-t-butyl-6,6'-bis-(5,6-diethyl-1,2,4-triazin-3-yl)-2,2'-bipyridine in water/2 propanol mixture

The complexation of Cm(III) and Eu(III) with 4-t-butyl-6,6-bis-(5,6-diethyl-1,2,4-triazin-3-yl)-2,2'-bipyridine (t-Bu-C2-BTBP) in water/2 propanol solution is studied. With increasing ligand concentration, 1:2 complexes [M(t-Bu-C2-BTBP)2(H2O)]3+ form from the solvated metal ions. The stability constants are logKCm(III) = 11.1 and logKEu(III) = 9.0. For both Cm(III) and Eu(III), the complexation reaction is both enthalpy and entropy driven. ¿HCm(III) is 11.7 kJ/mol more negative than ¿HEu(III), whereas the entropy difference is negligible. This is in good agreement with t-Bu-C2-BTBP's selectivity in liquid-liquid extraction.

TRUMM Sascha;  LIESER Georg;  PANAK P.J.;  GEIST A.;  FANGHAENEL Thomas;  FOREMAN Mark R. S. J.; 

2010-04-16

ROYAL SOC CHEMISTRY

JRC55029

1477-9226,   

https://publications.jrc.ec.europa.eu/repository/handle/JRC55029,   

10.1039/b919247f,