Background:

Disperse Blue 148 is the best high-temperature trichromatic blue azo dye.Target:Single-crystal structures of the best high-temperature trichromatic blue azo dye C.I. Disperse Blue 148 and its diazonium component 3-amino-5-nitro-[2,1]- benzisothiazole are described herein. C.I. Disperse Blue 148 exhibits an essentially coplanar molecular structure and a dimeric packing mode between adjacent phenyl and benzisothiazole rings. Particularly, PXRD measurement reveals the existence of a new crystalline form of C.I. Disperse Blue 148 having the highest melting point and the best thermal stability, which is obviously different from all the known α, β, and γ forms. [1]

[1]. Hui-Fen Qian, et al. Structural and spectral characterizations of C.I. Disperse Blue 148 having a new crystalline form. Dyes and PigmentsVolume 99, Issue 2, November 2013, Pages 489-495