POLYMERIZATION AND MOLECULAR RECOGNITION IN THE MONOLAYERS OF THE SURFACE-ACTIVE DERIVATIVES OF CROWN-ETHERS

The four surface-active derivatives of crown-ethers with a variety of fatty alkyl chains were synthesized and studied in monolayers at vario us conditions. The areas per crown-ether molecule in monolayers are in creasing significantly in the presence of various alkali metal cations in the aqueous subphase. These effects can be explained as complex fo rmation between crown-ethers in the monolayers and cations from aqueou s subphase, causing a change in the conformation of the polyether ring of the molecule at the interface. This is accompanied with the change in the cation selectivity (Na+ > Li+ > K+ > Cs+) as compared with the series in volume (K+ > Cs+ > Na+ > Li+). Polymerization of the crown- ether monolayer allows to stabilize the conformation of the molecule a t the interface as if tuned to the definite cation.