Studies on the molecular orientation of Flavin Langmuir-Blodgett films by FT-IR spectroscopy

The molecular orientation of flavin Langmuir-Blodgett films was studied by FT-IR transmission, reflection absorption and polarized transmission spectroscopy. It was concluded from these measurements that the flavin (isoalloxazine) ring takes a biaxial orientation; the long axis of the isoalloxazine ring almost takes an in-plane orientation to the substrate plane and is almost parallel to the dipping direction of the substrate at the time of preparation of the film. It was also concluded that the short molecular axis is oriented obliquely to the film plane.