Characteristic Infrared Frequencies of 3,3-Diphenylphthalides in the Region of 2000 to 330 Cm −1

Abstract

The infrared spectra of ten 3,3-bis(phenyl)-phthalides were obtained in order to select frequencies characteristic of the phthalide ring system, and to observe the effects of phenyl substitution in the 3 position of the phthahde ring system. Bands characteristic of the phthahde ring system per se were observed near 1284 cm⁻¹, 1107 cm⁻¹, 1016 cm⁻¹, 503 cm⁻¹, and 479 cm⁻¹. Bands characteristics of 3,3-bis (phenyl)-phthalides were seen near 632 cm⁻¹, 530 cm⁻¹, and 370 cm⁻¹. The effect of substituents on the 3,3-phenyl rings upon frequency was noted for several bands, bands characteristic of these substituents were also observed These data indicate that the various bands can be used for identification of the 3,3-bis(phenyl)-phthalide structure.