Infrared intensities as a quantitative measure of intramolecular interactions. XXXIX. Triaryl-phosphines, -phosphine oxides and -phosphine sulphides

Abstract

The infrared intensities for the v₈ ring stretching band of series of meta- and para-substituted triphenyl-phosphines, -phosphine oxides, and -phosphine sulphides indicate the σ°_R values: PPh₂,-0.08; PPh₂O, +0.07; PPh₂S, +0.06. All three groups show acceptor properties when para to a strong donor substituent.