Pyridylazonaphthols (PANs) and pyridylazophenols (PAPs) as analytical reagents. Part I. Synthesis and spectroscopic examination of reagents and some chelates

Abstract

2-(2-Pyridylazo)-1-naphthol (o-α-PAN), 2-(2-pyridylazo)phenol (o-PAP) and 4-(2-pyridylazo)phenol (p-PAP) have been prepared. They and 1-(2-pyridylazo)-2-naphthol (o-β-PAN) and their chelates with various transition metals have been examined and characterised by infrared spectroscopy and mass and nuclear magnetic resonance spectrometry. The purity and structures of the reagents have been established and it was confirmed that they are terdentate ligands.