1014. BBOT

Nomenclature

CAS number: 7128-64-5
2,2′-(2,5-Thiophenediyl)bis[5-(1,1-dimethylethyl)benzoxazole]; 2,5-bis(5-tert-butyl-2-benzoxazolyl)thiophene; C.I. Fluorescent Brightener 184; Uvitex OB (Ciba).
C26H26N2O2S; mol wt 430.56.
C 72.53%, H 6.09%, N 6.51%, O 7.43%, S 7.45%.

Description and references

High mol wt fluorescent whitening agent. Prepn: P. Liechti et al., CH 427822 (1967 to Ciba); Z. Seha, C. D. Weis, Helv. Chim. Acta 63, 413 (1980). Fluorescence depolarization studies: G. R. Fleming et al., Chem. Phys. Lett. 51, 399 (1977). Photostability study: G. Tury et al., J. Photochem. Photobiol. A 114, 51 (1998).

Chemical structure

Properties

Yellow to green powder, mp 196-202°. Flash pt: >350°C. d20 1.26. Vapor pressure (20°): 2.6×10-8 Pa. Soly at 20° (%w/w): water <0.01; acetone 0.5; chloroform 14; ethyl acetate 1; n-hexane 0.2; methanol <0.1. Absorption max (cyclohexane): 374 nm. Emission max (cyclohexane): 435 nm.

Use

Optical brightener additive in polymers, fibers, films, inks, laquers, and paints. In liquid scintillators.