Optical and dielectrical properties of 2-hydroxy-1-naphthylideneaniline and its derivatives

The optical and electrical properties of 2-Hydroxy-1-naphthylideneaniline and its derivatives (HLn) have been investigated. The spectral distribution of absorption (α) coefficient for the ligands HL1 and HL4 showed five absorption peaks and shoulders which are assigned as π–π* and n–π* transitions. The optical energy gap (Eg) for HL1 and HL4 is investigated and found to be in the range of 2.09–2.27 eV depending on the function group and the type of electronic transition. The ac conductivity measurements showed a semiconductor behavior. The electrical conduction mechanism was also investigated and found to be correlated barrier-hopping (CBH) and quantum mechanical tunneling (QMT) mechanisms depending on the function group. The effect of adsorbed NH3 gas on the electrical conductivity and dielectric constants of ligand HL3 was also investigated.