Heterocyclisch substituierte Arendiazoniumsalze mit erweiterter spektraler Empfindlichkeit. II. 4‐(1‐Heterocycliden‐2,3‐diaza‐prop‐2‐en‐3‐yl)‐benzendia‐zoniumtetrafluoroborate

Abstract

Heterocyclic Substituted Arenediazonium Salts with a Long‐wave‐length Range of Sensitivity. II. 4‐(1‐Heterocycliden‐2,3‐diaza‐prop‐2‐en‐3‐yl)‐arenediazonium tetrafluoroborates The title compounds (3) are obtained by reaction of aromatic bis‐diazonium salts with substituted 2‐benzylidene‐1,3‐dithioles and 2‐benzylidene‐1,3‐diselenole, respectively. The maximum of the long wave‐length absorption band of 3 varies from 580 nm up to 665 nm depending on the structure of the compound. The quantum yields of the photolysis of the diazonium salts 3 are low (1 · 10−4 to 7 · 10−3). The azo dyes obtained from 3 with usual azo‐couplers absorb in a shorter wave‐length range than the corresponding diazonium salts themselves (hypso‐coupling effect).