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. 

Technical Specifications:
C.A.S. No. 85-85-8
M.F. C15H11N3O
M.W. 249.27gm/mole



Solubility 0.1 %(0.1N EtOH) Clear solution
Absorption Maximum (in EtOH) ?max 462-466nm
Absorptivity (A1%/1cm in EtOH, at ?max) >670
Loss on drying (110°C) <5%
Suitability as metal indicator Passes test

Note: This article uses material from the