| 摘要 |
The invention relates to an optical recording medium comprising a substrate, a reflecting layer and a recording layer, wherein the recording layer comprises a compound of formula (I), or a mesomeric or tautomeric form thereof, wherein Z<n+> is a proton or an n-valent ammonium, phosphonium, metal complex or alkali metal cation and n is a number (1), (2) or (3); it being possible, where appropriate, for Z<n+ >to be linked to R1, R2, R3 or R4 by a direct bond or by way of an O, S or NR8 bridge. R1, to R7 are hydrogen or hydrocarbon radicals defined in the description and claims; R2 and R6 can additionally be halogen or nitro. Novel compounds of formula (I) are also claimed, these being compounds in which Z<n+ >is a phosphonium, metal complex or alkali metal cation or which are asymmetrical. |
