Optical information recording medium using metallized formazan dyes

A recordable optical element having a transparent substrate and on the surface of said substrate, a dye containing recording layer and a light reflecting layer, the improvement wherein said dye is a metallized formazan dye of the general structure:

• ##STR16## wherein:
• Z are the atoms necessary to complete a 5 or 6 membered carbocyclic or heterocyclic ring;
• each R.sub.1 independently is a group selected from the group consisting of alkyl having about 1 to 20 carbon atoms;
• aryl having from about 6 to 10 carbon atoms;
• heteroaryl;
• alkenyl having from about 2 to 20 carbon atoms;
• halogen;
• thiocyano;
• cyano;
• nitro;
• sulfo;
• carboxy;
• hydroxy;
• alkoxy;
• aryloxy;
• hetaryloxy;
• alkylsulfonyl;
• arylsulfonyl;
• hetarylsulfonyl;
• arylazo;
• hetarylazo;
• alkoxycarbonyl;
• aryloxycarbonyl;
• alkoxycarbonylamino;
• aryloxycarbonylamino;
• alkoxycarbonyloxy;
• aryloxycarbonyloxy;
• alkylcarbonylamino;
• arylcarbonyloxy;
• hetarylcarbonyloxy;
• alkylcarbonylamino;
• arylcarbonylamino;
• hetarylcarbonylamino;
• mono- or di-alkylaminocarbonyloxy;
• mono- or di-arylaminocarbonyloxy;
• mono- or di-hetarylaminocarbonyloxy;
• mono- or di-alkylaminocarbonylamino;
• mono- or di-arylaminocarbonylamino;
• mono- or di-hetarylaminocarbonylamino;
• mono or di arylcarbamoyl;
• alkyl or aryl carbamoyl;
• mono- or di- alkylsulfamoyl;
• mono- or di-arylsulfamoyl;
• and alkylarylsulfamoyl;
• R.sub.2 represents an alkyl group having from 1 to about 20 carbon atoms;
• a heterocyclic group having from 1 to about 10 carbon atoms, an aromatic ring with H or R.sub.1 substituents;
• CN;
• alkoxycarbonyl;
• NO.sub.2 ;
• alkylsulfonyl;
• arylsulfonyl;
• carbamoyl;
• sulfamoyl;
• each R.sub.3 independently represents H or R.sub.1 with the proviso that one of the R.sub.3 groups may serve as a fourth ligand to the metal center, if located ortho to the azo linkage and chosen from O--, N--SO.sub.2 R.sub.4 where R.sub.4 can be an alkyl group with one to ten carbon atoms or aryl group with five to ten carbon atoms, CO.sub.2 --, SO.sub.3 -- or --N.dbd.CH--;
• m and n independently represent integers from 0 to 4;
• L represents nitrogen or C--Y where Y represents a group capable of coordination to the metal ion such as O--, N--SO.sub.2 R.sub.4 (where R.sub.4 can be an alkyl group with one to ten carbon atoms or aryl group with five to ten carbon atoms) CO.sub.2 --, SO.sub.3 -- or N.dbd.CH--.
• M represents a complexing metal such as Ni, Pd, Zn, Cu, etc.
• V is the charge (valence) of the coordinating metal ion;
• X is a counter ion group balancing the charge Q on the metal complex such as a sodium ion, chloride ion, tetraalkylammonium, tetrafluoroborate, hexafluorophosphate etc.
• u is the number of counter ions required to balance the charge on the complex;
• Q is the charge on the metal complex representing the difference between the metal valence (V) and the total anionic charge provided by the formazan dye and auxiliary ligand (B)p;
• B is a ligand or ligands necessary to complete the coordination sphere of the metal ion and p is an integer from 0 to 3.