Structure of tribenzyloxyaluminium and tri-(4-chlorobenzyloxy)aluminium

Abstract

60 MHz and 220 MHz ¹H N.m.r. solution spectra of tribenzyloxyaluminium and tri-(4-chlorobenzyloxy)aluminium provide interesting examples of magnetic nonequivalence of the methylene protons in the alkoxy-groups. At temperatures of 40° or below the 60MHz methylene spectra consists of a singlet and an AB quartet whilst at 220 MHz two well resolved AB quartets are observed. These spectra, together with molecular weight measurements, are discussed and interpreted in terms of asymmetric tetrameric tetrameric molecules.