Bayer Aktiengesellschaft

Helmut Telle

Roderich Raue

Rudolf Schieder

Wolfgang Brinkwerth

Uwe Brinkmann

Wolfgang Huffer

Udo Eckstein

Carl-Wolfgang Schellhammer

Dyestuff laser consisting of a reservoir, with a laser dyestuff solution contained therein, and a pumped light source associated therewith, which is capable of exciting the dyestuff solution to produce an emission, characterized in that the dyestuff solution contains, in a solvent which does not interfere with the emission, a dyestuff which, in the form of the free acid, corresponds to the general formula ##STR1## wherein R.sub.1 to R.sub.4 independently of one another represent hydrogen, alkyl, trifluormethyl, alkoxy, aralkoxy, alkenyloxy, halogen or the carboxyl, cyano, alkylsulphone, aryl-sulphone, carboxamide, sulphonamide or carboxylic acid ester group,

Dyestuff laser

Fluorescent dyestuffs of the general formula ##STR1## wherein R and R.sup.1 independently of one another represent hydrogen, a salt-forming cation, an alkyl radical with 1 to 16 C atoms or an aryl or aralkyl radical which is optionally substituted by non-chromophoric groups,

Fluorescent dyestuffs, processes for their preparation and their use as

Fluorescent dyestuffs of the formula ##STR1## wherein: R.sub.1 and R.sub.2 independently of one another represent hydrogen, a salt-forming cation, an alkyl radical with 1 to 8 carbon atoms or an aralkyl radical which is optionally substituted by non-chromophoric groups,

Fluorescent dyestuffs

Laser light in the wavelength range of 400 - 480 Nm is obtained with a dyestuff laser containing a dyestuff of the general formula ##STR1## wherein E denotes one of the radicals ##STR2## R.sub.1 -R.sub.4 independently of one another denote hydrogen, alkyl, trifluoromethyl, alkoxy, aralkoxy, halogen, alkenyloxy, the carboxyl, cyano, alkylsulphone, arylsulphone, carboxamide or sulphonamide group or the carboxylic acid ester group, or R.sub.1 and R.sub.2, or R.sub.3 and R.sub.4, conjointly represent a fused benzene ring and m and n independently of one another denote 0, 1 or 2, with the proviso that the radical E contains at least one sulphonic acid group if m and n represent 0, and wherein

Laser light in the wavelength range of 420-480 nm is obtained with a dyestuff laser containing a dyestuff of the general formula ##STR1## wherein R and R.sub.1 independently of one another represent ##STR2## R.sub.2 denotes an optionally substituted alkyl radical with 1-4 C atoms, R.sub.3 and R.sub.4 independently of one another represent hydrogen or optionally substituted C.sub.1 -C.sub.4 -alkyl or conjointly with the nitrogen can form a 5-membered or 6-membered heterocyclic ring and

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Cologne, Germany

Helmut Telle