Compounds on the basis of 2- and 4-chromenylidene-merocyanines respectively, and their use

A compound of the formula I or II

• wherein
• (a) R1 and R3 to R12 may each be the same or different and is selected from the group consisting of hydrogen, chlorine, bromine, and a substituent selected from the group consisting of an alkyl, aryl, heteroaryl, cycloalkyl, heterocycloalkyl, alkyloxy, alkylmercapto, aryloxy, arylmercapto, heteroaryloxy, heretoarylmercapto, cyano, an isocyano, isothiocyano, hydrazino, amino, monochloro- and dichloro- or monobromo- and dibromo-triazinyl, aziridino, sulfonyl halogenid, N-hydroxysuccinyl, imido, glyoxyl, maleimido, iodacetamido, and phosphoramido;
• and wherein the substituent may also contain, apart from carbon and hydrogen, as many as 4 oxygen atoms and 0, 1 or 2 nitrogen atoms, or one sulfur atom, or one sulfur and one nitrogen atom;
• (b) R1 and R2, R2 and R3, R3 and R4, R5 and R6, and R6 and R7 together may form an aromatic, non-aromatic or nitrogen-containing 5- or 6-member ring;
• (c) X represents oxygen or sulfur;
• (d) n is zero, 1, 2 or 3;
• (e) and with the proviso that R2 must contain a nitrogen atom and is a substituted or unsubstituted amino group or a nitrogen-containing 5- or 6- membered ring.