Monolayers of amphiphilic azacrowns: characterization of monolayer behavior and specific interaction with nucleotides

A series of N-alkyl-substituted, amphiphilic azacrowns was synthesized by two methods. All derivatives form highly oriented monolayers at the gas/water interface. The monolayer behavior is strongly dependent on subphasic conditions such as the pH and the existence of ions, in contrast to analogous compounds derivatized through an N-acylation. Under conditions of carefully controlled pH and ionic strength some of these new derivatives exhibit a distinct selectivity for nucleotides (ATP > ADP > AMP). Multilayers of one of these nucleotide-sensitive compounds, having a well-defined layer spacing, could be prepared on hydrophobized quartz via Langmuir-Blodgett deposition.