| abstract |
PCT No. PCT/EP92/00693 Sec. 371 Date Sep. 27, 1993 Sec. 102(e) Date Sep. 27, 1993 PCT Filed Mar. 28, 1992 PCT Pub. No. WO92/17549 PCT Pub. Date Oct. 15, 1992.Methine dyes with a polyketo group I <IMAGE> I where A is <IMAGE> R1 is a 5- or 6-membered cycloaliphatic radical which contains one or two hetero atoms from the group -NR4-, -O- and -S- and which may be fused to an isoaromatic or heteroaromatic group, R2 and R3 are identical or different C1-C10-alkyl groups or together one of the radicals R1, and m and n are identical or different integers from 0 to 3, are useful as drugs, for producing singlet oxygen, as sensitizers in electrophotographic layers and for photopolymerizations and as laser light sensitive dyes in optical recording media; also novel triketo- and tetraketomethine dyes. |