[00.8] SUPRAMOLECULAR CHEMISTRY 12: (1) 27-51, Sp. Iss. SI 2000
Complexation of M3+ lanthanide cations by calixarene-CMPO ligands: A molecular dynamics study in methanol solution and at a water/chloroform interface
Laurent Troxler 1, Marc Baaden, Volker Böhmer 2, Georges Wipff1,*
We report a molecular dynamics study on the 1:1 M3+ lanthanide (La3+, Eu3+ and Yb3+) inclusion complexes of an important extractant molecule L: calixarene-tetraalkyl ether substituted at the wide rim by four NH-C(O)-CH2-P(O)Ph-2 arms. The M(NO3)(3) and MCl3 complexes of L are compared in methanol solution and at a water / chloroform interface. In the different environments the coordination sphere of M3+ involves the four phosphoryl oxygens and three to four loosely bound carbonyl oxygens of the CMPO-like arms. Based on free energy simulations, we address the question of ion binding selectivity in pure liquid phases and at the liquid-liquid interface where L and the complexes are found to adsorb. According to the simulations, the enhancement of M3+ cation extraction in the presence of the calixarene platform, examined by comparing L to the (CMPO)(4) "ligand" at the interface, is related to the fact that (i) the (CMPO)(4)Eu(NO3)(3) complex is more hydrophilic than the LEu(NO3) one and (ii) the free CMPO ligands spread at the interface, and are therefore less organized for cation capture than L.
Correspondence should be addressed to Prof. G. Wipff.
- Univ Strasbourg 1, CNRS, UMR 7551, Inst Chim, 4 Rue B Pascal, F-67000 Strasbourg, France.
- Univ Mainz, Fachbereich Chem & Pharm, Abt Lehramt Chem, D-55099 Mainz, Germany.
1 time cited on 2/2/2005 (Ref. ISI Web Of Science)