The aluminium(III) complexes of hydroxyflavones in absolute methanol. Part II. Ligands containing more than one chelating site
The complexes formed in absolute methanol between aluminium chloride and the multidentate ligands kaempferol, morin, quercetin, rutin, and 3,3′,4′-trihydroxyflavone have been studied by u.v. and visible spectroscopy. The stoicheiometry of the complexes favoured at various metal to ligand ratios, and under a range of acidity conditions, has been established by the method of molar-ratios. From this data the preferred site for complex formation, in acid, neutral, and basic solution, has been established for each ligand.