可視・赤外光和周波分光法による同位体を混合したステアリン酸カドミウムＬＢ膜の観測

Abstract

Stearic acid (CH3(CH2)16COOH) cadmium Langmuir-Blodgett (LB) films have been formed with changing the mixing ratio between stearin acid and the deuterated one. Then, vibrational sum frequency generation (SFG) spectra of the top odd layer of the mixed LB films have been taken. In the SFG spectra, there were no peaks attributed to CH2 stretching vibrational modes. These results indicate that the mixed LB films were constructed by nearly all-trans stearin acid molecules, and had well-ordered packing structure. With increase of the mix ratio of deuterated stearin acid, the peak position of CH3 symmetric stretching mode was red-shifted with ~ 2 cm-1, while the peak position of CD3 symmetric stretching mode was blue-shifted. This tendency is qualitatively consistent with vibrational modulation due to dipole-dipole interaction.