ORIENTATION OF P-NITROPHENOL MOLECULES INDUCED BY EPITAXIAL CRYSTALLIZATION ON FRICTION-TRANSFERRED POLY(TETRAFLUOROETHYLENE) SUBSTRATES

The crystallization of p-nitrophenol molecules (PNP) onto monooriented poly(tetrafluoroethylene) (PTFE) films prepared by friction transfer on glass slides was found to yield highly oriented thin layers of the former species. Polarized Fourier-transform infrared spectroscopy and X-ray diffraction studies clearly show that the thin PNP layers adopt the beta crystal form and have a single-crystal-like orientation with a (001) contact crystal plane, the crystallographic alpha axis being aligned with the PTFE chain axis. Materials of this outstanding orientation are very suitable for analysis by FTIR spectroscopy of the crystal field effect on molecular vibrations.