Azomethine derivatives. Part XIII. Azomethine stretching frequencies of some di- and tri-substituted methyleneamines, their hydrochlorides, and their boron trifluoride adducts

Abstract

Details of the i.r. spectra of the imines Ph₂C:NH, p-BrC₆H₄(Ph)C:NH, (p-ClC₆H₄)₂C:NH, (p-tolyl)₂C:NH, p-tolyl-(Bu^t)C:NH, Bu₂^tC:NH, Ph₂C:NMe, Ph₂C:NPh, PhCH:NMe, and PhCH:NPh, their hydrochlorides [R¹R²C:NR³H]⁺Cl^–, and their boron trifluoride, adducts R¹R²C:NR³,BF₃, are reported. On co-ordination of the imine to a proton or boron trifluoride, the frequency of the azomethine stretching vibration ν(C:N)increases to an extent (Δν= 5 → 64cm.^–1) which depends on R¹, R², and R³. Factors affecting ν(C:N) and Δv are briefly discussed.