High-Resolution Infrared and Raman Spectra of the Polycrystalline Sinomenine Hydrochloride

Abstract

High-resolution infrared and Raman spectra of the polycrystalline sinomenine (SM) hydrochloride have been measured to work out its whole really existing vibrational spectral bands. Except for the hydroxyl stretching modes and IR active bands less than 400 cm−1, most normal modes (about 34) are both IR and Raman active. In addition, 8 Raman bands less than 400 cm−1 are tentatively assigned, for the first time to our knowledge, to stretching/bending modes of the aromatic-ring−methoxyls and (SMH)+–Cl− ions, respectively.