Synthesis of novel near-infrared absorbing metal complex dyes with indoaniline-type ligands

Abstract

New metal complex dyes with N,O-bidentate indoaniline-type ligands, 5-(4′-dialkylaminophenylimino)quinolin-8-ones (3), have been prepared, which have intense absorption bands in the near-i.r. region and were isolated as stable compounds. A film of complex dye which was prepared from 5-(4′-diethylamino-2′-methylphenylimino)quinolin-8-one and Ni(BF₄)₂aq showed a λ_max value of 772 nm and reflected 54.3% of the incident light intensity at 830 nm; these metal complex dyes have potential as a diode-laser optical storage medium.