| abstract |
New dibenzofuranylbiphenyl compounds of the formula (I) are described which are optionally substituted one or more times with radicals R = hydrogen, C₁-C₄-alkyl, C₁-C₄-alkoxy, halogen, phenoxy and benzyloxy and in which R₃ = C₁-C₄-alkyl, halogen or phenyl, M = hydrogen and / or mean an equivalent of a non-chromophoric cation, their preparation and use for optical brightening. |