Detection of chiral disorder in langmuir monolayers undergoing spontaneouschiral segregation

Acid-base interactions between two different chiral amphiphilic molecules ( p-pentadecylmandelic acid and p-tetradecylphenylethylamine) are used in ord er to achieve spontaneous chiral segregation from a racemic mixture at the air-water interface, as shown by grazing incidence X-ray diffraction. The e xtent of possible chiral disorder for both acid and base components is exam ined. We show that an oblique lattice symmetry is insufficient to guarantee spontaneous segregation of chiral molecules in two-dimensional crystals be cause of possible chiral disorder.