Complex formation of bivalent einsteinium with perchlorate, tetrafluoroborate, and tetraphenylborate ions in tetrahydrofuran

Cocrystallization technique was used to study the effect of perchlorate, tetrafluoroborate, and tetraphenylborate ions on the behavior of bivalent einsteinium in tetrahydrofuran (THF). It was found that addition of ClO4- and BF4- affects and addition of BPh4- does not affect the cocrystallization coefficients of Es2+ with solid [Sr(18-crown-6)]I-2 in THF solution. On the basis of the experiments, it was concluded that the stability of complexes increases when passing from BF4- to ClO4- whereas Es2+ does not form complexes with BPh4- in THF.