A New Type of Light Stabilizer for Dye Layers of Optical Disks: Tetracyanoquinodimethane Derivatives

Abstract

A new technology to improve the light fastness of cyanine dye layers of a compact disk recordable (CD-R) or a digital video disk recordable (DVD-R) without using any singlet oxygen quenchers was discussed. The light fastness of dicarbocyanine dye layers of a CD-R was improved by doping with tetracyanoquinodimethane (TCNQ) derivatives of various reduction potentials (E 1/2 RED). The optimum potential was found to be around 0 V vs saturated calomel electrode (SCE). Doping with TCNQ derivatives was found to be effective also for the improvement of light fastness of the carbocyanine dye layers which have optical properties suitable for a DVD-R disk. Excessive electron demanding TCNQ derivatives (E 1/2 RED> 0), however, showed rather poor jitter and block-error rate (BLER) after exposure to a xenon lamp as compared to a TCNQ derivative (TCNQ1) with an optimal reduction potential (ca. 0 V vs SCE). Since TCNQ derivatives have no absorption band in a red to near infrared region, the CD-R or the DVD-R having cyanine dye layers doped with TCNQ derivatives exhibit higher reflectivity than those with such singlet oxygen quenchers as diimmonium salts.

Current Developments in Optical Data Storage with Organic Dyes

“…The stabilizing action of tetracyanoquinodimethanes has also been described, which act as powerful electron acceptors and quench the excited singlet state of the cyanines. [87,88] Furthermore, azo-metal complexes [89][90][91][92][93] and formazan-metal complexes [94] are suitable for improving light stability. Thus, a broad palette of oxygen scavengers are available, which makes it possible to produce highly lightstable layers in CD-R and DVD/R, even with cyanine dyes.…”

Determination of the structure of 1,1′-diethyl-2,2′-carbocyanine iodide using NMR spectra and GIAO-HF/DFT calculations

“…This special property has resulted in their use in the photographic industry as a spectral sensitizer [2,3]. They can also be applied in optoelectronics [4,5] and data storage [6,7], as molecular probes in biological systems [8,9], and in solar cells [10,11].…”

Aktuelle Entwicklungen in der optischen Datenspeicherung mit organischen Farbstoffen

“…Auch die stabilisierende Wirkung von Tetracyanchinodimethanen wurde beschrieben, die starke Elektronenacceptoren sind und den angeregten Singulettzustand der Cyanine löschen. [87,88] Darüber hinaus eignen sich sowohl Azo-Metallkomplexe [89][90][91][92][93] als auch Formazan-Metallkomplexe [94] zur Verbesserung der Lichtbeständigkeit. Somit steht eine breite Palette an Sauerstoff-Fängern zur Verfügung, die es ermöglichen, sehr lichtstabile Schichten von Cyaninfarbstoffen in CD-R und DVD/R zu erzeugen.…”