MD-SIMULATIONS ON UO2(2-SOLUTION AND AT A WATER() AND SR2+ COMPLEXES WITH CMPO DERIVATIVES IN AQUEOUS)CHLOROFORM INTERFACE/

Based on molecular dynamics simulations, we compare the UO22+ and Sr2 complexes of 1:1 and 1:2 stoichiometries with two different CMPO liga nds in water, including NO3- counterions. All complexes retain CMPO bi nding to the cation via direct coordination of O-(p) and medium-range interactions with the O-(c) oxygen. In solution, the complexed UO22+ i s directly coordinated to one or two water molecules, and to the count erions. The Sr2+ complex is more hydrated than UO22+ and its counterio ns are more dissociated. Replacement of methyl by phenyl phosphoryl su bstituents in CMPO is shown to increase the cation interactions with t he ligand. The preferred binding of UO22+ compared to Sr2+ is related to the stereochemical differences in their water coordination pattern, and to the weaker water affinity for the complexed UO22+ cation. Fina lly, we report the first simulations on one free CMPO and its complexe s at a water/chloroform interface, including NO3- counterions. The fre e ligand and its complexes remain adsorbed at the interface, instead o f spontaneously migrating to the organic phase. They behave therefore as surfactants.