Co-ordinating properties of some ligand systems related to 4-(2-pyridylazo)resorcinol.
The metal-complexing properties of 2-(8-quinolylazo)-1-naphthol-4-sulphonic acid and the 2-pyridyl-, 2-pyrimidyl- and 8-qumolylhydrazones of salicylaldehyde have been described and compared with those of 4-(2-pyridylazo)resorcmol and related dyes. The sensitive chromophoric action of metal ions on the latter group of dyes is thought to be due to the formation of a resonance-stabilized anion in which the heterocyclic nitrogen atom plays an important part. Ligands capable of forming chelates containing larger rings give on reaction with metals less sensitive colour reactions but more stable complexes.
Anderson
R G
RG
Department of Inorganic Chemistry, School of Chemistry, The University, Bristol 8, U.K.
Nickless
G
G