Chiral Discrimination in Langmuir Monolayers of N-eicosanoylproline Methyl Ester

Monolayers of chiral (L) and of racemic N-eicosanoylproline methyl ester have been investigated using surface pressure isotherm measurements and Brewster angle microscopy. The surface pressure isotherms indicate differences between the chiral and racemic monolayers; however, the differences appear somewhat smaller than those previously observed for monolayers of other N-acylamino acids capable of amideamide hydrogen bonding. The surface pressure isotherms exhibit hysteresis during compression-expansion cycles. The domains formed on compression of both the racemic and chiral monolayers are small and irregular, in contrast to the dendritic or curved domains previously observed for monolayers of N-acylamino acids capable of amideamide hydrogen bonding.