Well-ordered structure of N-octadecanoyl-L-alanine Langmuir-Blodgett film studied by FTIR spectroscopy

N-Octadecanoyl-L-alanine Langmuir-Blodgett films have been studied by FTIR grazing angle reflection and transmission measurements. The N-H and C=O (in amide and carboxylic acid) groups are oriented almost parallel to the substrate surface. The hydrocarbon chains are tilted regularly with a preferred orientation of C-C-C planes parallel to the substrate surface. The anisotropic arrangement of enantiomeric molecules that twist from neighbor to neighbor gives the aggregate chirality in the two-dimensional condensed state. (C) 1999 Elsevier Science B.V. All rights reserved.