| Popis: |
This chapter discusses the characteristic frequencies of ethers and peroxides. The characteristic frequencies of ethers and peroxides are because of the vibrations involving C—Ο linkage and O—Ο bonds, respectively. Furthermore, the C–Η vibrations for —OCH 3 , —OCH 2 —, and —OCH— ethers occur at different frequencies than those observed in alkanes. The characteristic COC vibrations in ethers are approximated as antisymmetric COC stretch, symmetric COC stretch, and COC deformation. However, these vibrations are far more complex than simply COC vibrations because of strong interaction between the C—Ο and all C—C bonds in the molecule. The characteristic frequency in the vibrational spectra of peroxides is because of the O—O stretching mode. Raman spectroscopy is a good technique to investigate the presence of the peroxy group because the O—Ο stretching gives rise to strongly polarized Raman bands about 900–700 cm −1 but only to weak IR absorption. |
