Infrared Spectra of Organic Phosphates in the Combination Region of the C—O and P—O Vibrations

Recently, the organic phosphorus compounds have gained attention because of their use in solvent-extraction separations. The infrared spectra of these compounds may be used to give important information concerning their composition. The infrared spectral assignments of these compounds have been conducted by several workers. According to them, the P=O stretching vibration in many compounds appears in the region of 1170–1310 cm−1. The C–O and P–O stretching vibrations in the P–O–C bond are also assigned at 1020–1050 cm−1 and 1020 cm−1, respectively. As these vibrations are coupled to each other, it is difficult to distinguish between the P–O and C–O bands.