Extraction experiments show that 2-benzylphenol is an efficient and selecti
ve extractant for cesium. The structures of cesium and potassium 2-benzylph
enolate were determined. Both structures also contain 2-benzylphenol, which
ligates the cation, through its phenolic oxygen atom and the benzyl ring.
The phenolate oxygen atom does not directly contact the cation in either st
ructure, but is a hydrogen-bond acceptor to the 2-benzylphenol ligands, for
ming a supramolecular assembly. For comparison to the bound ligands, the st
ructure of 2-benzylphenol was also determined. Molecular mechanics and ab i
nitio molecular orbital theory are used to rationalize several aspects of C
s/Na selectivity.