FLUORESCENCE MICROSCOPY STUDY OF CHIRAL DISCRIMINATION IN LANGMUIR MONOLAYERS OF N-ACYLVALINE AND N-ACYLALANINE AMPHIPHILES

Monolayers of L- and of racemic N-palmitoylvaline, N-stearoylvaline, a nd N-palmitoylalanine have been investigated using fluorescence micros copy and surface pressure isotherm measurements. The condensed phase d omains formed from the racemic films of the valine derivatives exhibit ed large arms curved clockwise or counterclockwise with equal probabil ity. Very rapid compression resulted in the formation of globular doma ins in the racemic films of the valine derivatives. In contrast, the c ondensed phase domains formed from the racemic films of the alanine de rivative were irregular and branched, indicating a sensitivity to the head-group size. The monolayers of the pure L enantiomers of all these compounds exhibited dendritic growth of the condensed phase.