Uses
1-(2-Pyridylazo)-2-naphthol is an indicator of transition metals. 1-(2-Pyridylazo)-2-naphthol is an indicator in complexometry and a reagent for the extraction and spectrophotometric determination of many transition metals. Dyes and metabolites.
Chemical Properties
orange crystals
Uses
1-(2-Pyridylazo)-2-naphthol is an indicator of transition metals. 1-(2-Pyridylazo)-2-naphthol is an indicator in complexometry and a reagent for the extraction and spectrophotometric determination of many transition metals. Dyes and metabolites.
Definition
ChEBI: 1-(2-pyridin-2-yldiazenyl)-2-naphthol is a member of naphthols.
General Description
1-(2-Pyridylazo)-2-naphthol (PAN), an orange colored dye, is commonly used as an acid-base indicator. It can form chelates with metal ions, which makes it a valuable indicator in complexometric titrations. PAN is also a spectrophotometric reagent, which can extract metal chelates into an organic solvent.
Agricultural Uses
1-(2-Pyridylazo)-2-naphthol is a hard stratum of strongly compacted soil caused by continual plowing to the same depth of hardened soil which has high clay content. The precipitated iron and silicates cement the soil particles and form pans. 1-(2-Pyridylazo)-2-naphthol often impede drainage and root growth. It can be broken up using a subsoiler .
Purification Methods
Purify PAN by repeated crystallisation from EtOH or MeOH. It can also be purified by sublimation under vacuum. Purity can be checked by TLC using a mixed solvent (pet ether/Et2O/EtOH; 10:10:1) on a silica gel plate. It has pK1 1.9 and pK2 12.2 in 20% aqueous ethoxyethanol. It chelates with copper [Pease & Williams Anal Chem 31 1046 1959]. [Beilstein 22 I 694, 22 III/IV 7073, 22/4 V 618.]
