Product Overview
2,5-Bis(5-tert-butyl-2-benzoxazolyl)thiophene, commonly known as BBOT or Optical Brightener OB, is an organic fluorescent whitening agent belonging to the benzoxazole-based optical brightener family. It has the molecular formula C₂₆H₂₆N₂O₂S and a molecular weight of 430.57 g/mol. The compound is generally supplied as a pale yellow to yellow powder or crystalline solid.
BBOT works by absorbing ultraviolet light and converting part of that energy into visible blue fluorescence. This optical effect helps reduce the appearance of yellow tones and improves the perceived whiteness and brightness of compatible materials. It is particularly useful in polymer and industrial material formulations where optical appearance is important.
The compound is used as an optical brightener in thermoplastic resins, including polyvinyl chloride (PVC), acrylic resins, and polyester fibers. It is also applicable in paints, coatings, and printing inks. In addition, its fluorescent properties make it useful in specialized analytical and material-related applications. BBOT is insoluble in water but soluble in certain organic solvents, including acetone and toluene. Its melting point is approximately 199–205°C, depending on the product specification. These properties make it a useful functional additive for manufacturers developing fluorescent whitening solutions and specialty materials.
2,5-Bis(5-tert-butyl-2-benzoxazolyl)thiophene Chemical Properties
Melting point | 199-201 °C(lit.) |
Boiling point | 531.2±45.0 °C(Predicted) |
density | 1.26 |
refractive index | 1.6360 (estimate) |
Fp | >350°C |
storage temp. | Keep in dark place,Sealed in dry,Room Temperature |
solubility | toluene: soluble50mg/mL |
form | powder |
pka | 3.03±0.10(Predicted) |
color | Pale Green to Yellow |
Water Solubility | Soluble in acetone and toluene. Insoluble in water. |
λmax | 373nm(EtOH)(lit.) |
Merck | 14,1014 |
BRN | 631803 |
Stability: | Stable. Incompatible with strong oxidizing agents. |
InChIKey | AIXZBGVLNVRQSS-UHFFFAOYSA-N |
LogP | 8.6 at 25℃ |
CAS DataBase Reference | 7128-64-5(CAS DataBase Reference) |
NIST Chemistry Reference | Benzoxazole, 2,2'-(2,5-thiophenediyl)bis[5-(1,1-dimethylethyl)-(7128-64-5) |
EPA Substance Registry System | 2,2'-(2,5-Thiophenediyl)bis[5-tert-butylbenzoxazole] (7128-64-5) |
Safety Information
Risk Statements | 36/37/38 |
Safety Statements | 24/25 |
WGK Germany | 1 |
RTECS | DM4888332 |
TSCA | Yes |
HS Code | 29349990 |
Toxicity | LD50 orl-rat: >10 g/kg MVCRB3 2,193,1973 |
