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Synthesis of Metal-Azo Dyes and Their Optical and Thermal Properties as Recording Materials for DVD-R

2002; Oxford University Press; Volume: 75; Issue: 9 Linguagem: Inglês

10.1246/bcsj.75.2067

1348-0634

Hyeyoung Park, Eung-Ryul Kim, Dong-Jin Kim, Haiwon Lee,

Nonlinear Optical Materials Studies

Abstract Four kinds of azo dyes and their metal-azo dyes were synthesized in order to obtain a high reflective index and better thermal stability as a recording material for DVD-R. Several kinds of novel azo dyes based on benzoic acid, 6-methoxybenzothiazole, benzothiazole-6-carboxylic acid, and benzimidazole have been synthesized. These azo dyes reacted with metal ions, such as Ni2+, Cu2+, Zn2+, and Co2+, as ligands. All structures of the compounds were confirmed by 1H-NMR and FT-IR analyses. The optical and thermal properties of azo dyes and their metal-azo dyes were characterized by UV-vis and TGA analyses. In the UV-vis spectra, the absorption maxima of metal-azo dyes show at longer wavelength than those of azo dyes. These spectral shifts are affected by substituent groups, electron-donating or -withdrawing groups, of azo dyes and metal ions. The metal-azo dyes were thermally stable up to 300 °C, which were confirmed by TGA analyses. Particularly, in the case of an azo dye complexed with Zn based on 6-methoxybenzothiazole, good absorption at 635 nm was observed, and its thermal stability was maintained up to 300 °C, with high refractive index of about 2.08.