Patent ID: 6849315

Claim:
An optical recording medium, comprising a substrate and a recording layer, wherein the recording layer comprises a compound of formula (I) wherein R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 , R 10 , R 11 , R 12 and R 13 are each independently of the others hydrogen, G 1 , or C 1 -C 24 alkyl, C 2 -C 24 alkenyl, C 2 -C 24 alkynyl, C 3 -C 24 cycloalkyl, C 3 -C 24 cycloalkenyl, C 7 -C 24 aralkyl, C 6 -C 24 aryl, C 4 -C 12 heteroaryl or C 1 -C 12 heterocycloalkyl, each unsubstituted or substituted by one or more identical or different substituents G 1 , wherein R 1 and R 2 , R 1 and R 13 , R 2 and R 3 , R 3 and R 4 , R 4 and R 5 , R 5 and R 6 , R 6 and R 7 , R 7 and R 8 , R 8 and R 9 , R 9 and R 10 , R 10 and R 11 , R 11 and R 12 and/or R 12 and R 13 can independently of one another be bonded to one another in pairs separately or, when they contain substitutable sites, via a direct bond or via a —CH 2 —, —O—, —S—, —NH— or —NC 1 -C 24 alkyl-bridge in such a manner that, together with the atoms and bonds indicated in formula (I), five- or six-membered, saturated, unsaturated or aromatic, unsubstituted or G 1 -substituted rings are formed, G 1 is any desired substituent, X m− is an inorganic, organic or organometallic anion, Y n+ is a proton or a metal, ammonium or phosphonium cation, and m and n are each independently of the other a number from 1 to 5, and p and q are each independently of the other 0 or a number from 0.2 to 6, the ratio of p and q to one another, depending upon m and n and, as applicable, the number of charged G 1 , being such that in formula (I) there is no excess positive or negative charge.