表面增强拉曼散射(SERS)光谱研究含偶氮基长链脂肪酸薄膜

表面增强拉曼散射（ＳＥＲＳ）光谱研究含偶氮基长链脂肪酸薄膜吴玉清赵冰徐蔚青陶艳春吴英李伯符（吉林大学超分子结构与谱学开放实验室１３００２３）ＳｕｒｆａｃｅＥｎｈａｎｃｅｄＲａｍａｎＳｐｅｃｔｒｏｓｃｏｐｉｃＳｔｕｄｙｏｆＡｚｏｂｅｎｚｅｎｅＣｏｎｔａ...

Surface Enhanced Raman Spectroscopic Study of Azobenzene Containing Long chain Fatty Acid Langmuir Blodgett Film

Abstract Langmuir Blodgett film and casting film on the nitric acid etched silver foil of C 8 H 17 O N=N O C 3H 6COOH (abbreviated as 8A3H) has been studied by Surface Enhanced Raman Spectroscopy(SERS). The strong peaks at 1138, 1409 and 1450 cm -1 are assigned to phenyl N and the Fermi resonant doublets of the trans N=N stretching mode, respectively. Both SERS spectra of casting film and LB film have good signal to noise ratio. It is noted that there are signficant differences in the doublet vibration frequencies of the N=N stretching mode and that of 1191 cm -1 between the LB film and solid state spectra. The band due to the N=N stretching mode shows an upward shift by about 7 cm -1 in the former, and 4 to 2 cm -1 up shift for 1191 cm -1 and 1138 cm -1 peaks, respectively. These are all attributed to the surface enhanced raman effect of the silver foil. The freguercy shifts of 8A3H LB film and casting film compared to the solid state are larger than those of 8A5H. The intensily ratio of the Fermi douslet at ca 1410 and 1457 cm -1 of 8A5H LB film and casting film is the same as that of 8A3H and is thus different from that of 8A5H solid state. This results may be due to the difference between the length of hydrocarbon chain in the head region.