Distyrylbiphenyls

Abstract

The distyrylbiphenyls of the formula ##STR1## in which X and X' independently of one another are a direct bond, oxygen, sulfur, --O--C.sub.1-3 -alkylene-CON(R.sub.4)--CON(R.sub.4)--, --O--C.sub.1-3 alkylene-COO--, OCO or --COO--, with the proviso that if n+n'=O, X and X' may not be --CON(R.sub.4)-- or O--C.sub.1-3 -alkylene-CON(R.sub.4)--, and if n+n'=2 and X and X' are --CON(R.sub.4)-- or --COO--, A.sup..crclbar. may not be a phosphite or phosphonate anion, and Y and Y' independently of one another are C.sub.1-20 -alkyene, R.sub.1 and R.sub.1 ' independently of one another are unsubstituted or substituted C.sub.1-8 -alkyl or C.sub.3-4 -alkenyl, R.sub.1 together with R.sub.2, or R.sub.1 ' together with R.sub.2 ', is a heterocyclic ring, R.sub.2 and R.sub.2 ' independently of one another are unsubstituted or substituted C.sub.1-8 -alkyl or C.sub.3-4 -alkenyl, or R.sub.2 together with R.sub.1, or R.sub.2 ' together with R.sub.1 ', is a heterocyclic ring, or R.sub.1 and R.sub.2, or R.sub.1 ' and R.sub.2 ', together with R.sub.3 are a pyridine or picoline ring, R.sub.3 is hydrogen, unsubstituted or substituted C.sub.1-4 -alkyl or C.sub.3-4 -alkenyl or together with R.sub.1 and R.sub.2, or with R.sub.1 ' and R.sub.2 ', is a pyridine or picoline ring, R.sub.4 is hydrogen or unsubstituted or substituted C.sub.1-6 -alkyl, A.sup..crclbar. is a colorless anion and n and n' independently of one another are the number 0 or 1, and the benzene nuclei B and C can also be substituted by non-chromophoric substituents, can be prepared by reacting a correspondingly substituted benzaldehyde with a biphenyl phosphonate and then alkylating or protonating the distryrylbiphenyldiamine formed. The distyrylbiphenyls are fluorescent brightening agents for organic materials. They are particularly suitable for use as additives for textile and laundry after-treatment agents which contain cationic textile softeners.