MOLECULAR ARRANGEMENTS AND POLYCONDENSATION OF LONG-CHAIN ESTERS OF AMINO-ACIDS CONTAINING AN AROMATIC RING IN LANGMUIR-BLODGETT-FILMS

Octadecylesters of L-1-naphthylalanine and L-1-pyrenylalanine were syn thesized. Both compounds form stable condensed monolayers at the air-w ater interface and can be transferred onto solid plates by the vertica l dipping and horizontal lifting methods to give the alternating Y-typ e and non-alternating X-type films respectively. The orientation and p acking of the aromatic rings depend upon the deposition methods and th e surface pressures, as indicated by UV, circular dichroism and fluore scence spectra. Poly-amino acids containing the pi-electron systems as a side group could be obtained in the LB films. For the Y-type films, the oligomer was obtained in the first step at 25-degrees-C, and then the poly-amino acid with a random coil was produced by increasing the temperature to 40-degrees-C, as suggested by the amide I bands at 169 0 and 1650 cm-1. The conversion in the X-type film was very low compar ed with that in the Y-type film. It is considered that the interlayer reaction propagates by ''sewing up'' the amino and the ester groups fa cing each other at the adjacent layers in the Y-type films.