Spectroscopic, thermal, and recording properties of metal(II)-azo complexes for blu-ray recording materials

Three kinds of novel metal(II)-azo complexes based on indandione were synthesized in order to obtain a suitable optical recording medium for blu-ray disc-recordable (BD-R). Smooth thin films of these metal(II)-azo complexes were prepared by spin-coating method. Absorption spectra, thermal decomposition and blu-ray static recording properties of the thin films were investigated. These metal(II)-azo complexes, with absorption peaks at 435 - 444nm wavelength region, have high thermal stability with sharp thermal decomposition thresholds. The results of the blue-ray (405nm) static optical recording test of these metal(II)-azo complexes indicated that high reflectivity contrast (>50%) can be obtained at appropriate laser power and pulse width, and the size of the recording mark on the Co(II) complex film is as small as 200nm at writing laser power of 2mW and pulse width of 300ns. These results imply that metal(II)-azo complexes based on indandione are promising candidates as recording media of BD-R.