New Solvatochromic Dyes of the 5-Dimethylamino-5'nitro-2,2'-bithiophene Type.
The first serious competitor to the known solvatochromic pyridiniumphenolate betaines has been uncovered with the 5-dimethylamino-5'-nitro-2,2'-bithiophene 1 a (X=Z=S, Y=CH, R=CH(3)), which has the added benefit of being notably sensitive to solvent in acidic media. By simple heterocyclization further compounds of the general type 1 have been synthesized, and their suitability as solvent indicators was investigated. In this way a new record was set with the selenophene analogue of 1 a.
Hartmann
H
Fachbereich Chemie der Fachhochschule Merseburg Geusaer Strasse, 02617 Merseburg (Germany).
Eckert
K
Schröder
A