Abstract: Cationic compounds of the formula (1) ##STR1## in which R denotes alkyl, hydroxyalkyl, alkoxyalkyl, phenylalkyl, or phenoxyalkyl,R' denotes alkyl, hydroxyalkyl, benzyl, or allyl andX.sup.(-) denotes a colorless anion, process for their manufacture and their use.

Abstract: Cationic compounds of the formula (1) ##STR1## in which R denotes alkyl, hydroxyalkyl, alkoxyalkyl, phenylalkyl, or phenoxyalkyl,R' denotes alkyl, hydroxyalkyl, benzyl, or allyl andX.sup.(-) denotes a colorless anion,process for their manufacture and their use.

Abstract: Compounds of the general formula (1) ##STR1## wherein R.sub.1 denotes hydrogen, halogen, alkyl, alkoxy or, conjointly with R.sub.2, a fused benzo ring, R.sub.2 denotes hydrogen, alkyl, alkoxy, halogen, phenyl, cyano, carboalkoxy, carboxyl, carbonamido, monoalkylcarbonamido, dialkylcarbonamido, sulfo, alkylsulfonyl, alkyloxysulfonyl, sulfonamido, monoalkylsulfonamido or dialkylsulfonamido or, conjointly with R.sub.3, a fused benzo ring, R.sub.3 has the same meaning as R.sub.2, R.sub.4 denotes hydrogen, alkyl, alkoxy, halogen or, conjointly with R.sub.3, a fused benzo ring, R.sub.5 denotes alkyl, hydroxyalkyl, alkoxyalkyl, optionally substituted aralkyl, cyanoethyl, cycloalkyl or a group of the formulae --CH.sub.2 CN, --CH.sub.2 CONH.sub.2 or --CH.sub.2 COO--alkyl, A denotes a group of the formulae ##STR2## or--(CH.sub.2).sub.4 --R.sub.6 denotes hydrogen, alkyl, hydroxyalkyl, alkoxyalkyl, aralkyl or optionally substituted phenyl, n denotes 1, 2 or 3 and X.sup.

Abstract: Novel 1,3,4-oxadiazolone-(2) compounds of the formula ##STR1## wherein Y denotes carboxy optionally functionally modified or optionally substituted phenyl or a five-membered heterocycle optionally substituted and selected from the group consisting of: furan, thiophen, oxazole, imidazole, oxadiazole, oxadiazolone, triazole, benzofuran, thionaphthalene, benzoxazole, benzimidazole, and benzotriazole, R denotes hydrogen, alkyl or optionally substituted phenyl, n denotes 0 and 1 and the rings A and B carry optionally further non-chromophoric substituents. These compounds may be used as optical brighteners.