Acylating Friedel–Crafts complexes: multinuclear NMR data and chemical reactivity

Abstract

¹³ C, ²⁷Al and ¹⁷O NMR investigations about the nature of the 1 : 1 system AlCl₃·RCOCl (R = CH₃, CH₂Cl, CHCl₂, CCl₃) in CH₂Cl₂ show a donor–acceptor structure with the carbonyl oxygen involved in the metal co-ordination. The shift of the carbonyl group resonance (Δδ) in ¹³C and ¹⁷O NMR spectra is strongly dependent on the electron-withdrawing power of the R group and shows a close connection with the reactivities of the different acyl complexes.