2,2',7,7'-Tetrabromo-9,9'-spirobifluorene

Description

2,2′,7,7′-Tetrabromo-9,9′-spirobifluorene is a spirobifluorene (SBF) derivative and is used as a blue-emitting material in electroluminescent devices. The spirobifluorene linkage in the molecule helps in decreasing the crystallization tendency and also increases the colour stability by preventing the formation of aggregates or excimers. They possess high photoluminescence efficiency and good chemical stability.

Chemical Properties

White to light yellow powder

Uses

2,2'',7,7''-Tetrabromo-9,9''-spirobifluorene is used in the preparation of OLEDs using amorphous compounds with spiro-bifluorene core.

Uses

2,2',7,7'-Tetrabromo-9,9'-spirobifluorene is used in the preparation of OLEDs using amorphous compounds with spiro-bifluorene core.

Application

Blue light emitting material in Organic Light Emitting Diodes (OLEDs).

General Description

2,2′,7,7′-Tetrabromo-9,9′-spirobifluorene is a spirobifluorene (SBF) derivative and is used as a blue-emitting material in electroluminescent devices. The spirobifluorene linkage in the molecule helps in decreasing the crystallization tendency and also increases the colour stability by preventing the formation of aggregates or excimers. They possess high photoluminescence efficiency and good chemical stability.

Synthesis

General procedure for the synthesis of 2,2',7,7'-tetrabromo-9,9'-spirobifluorene from 9,9'-spirobifluorene: 80 mg (0.5 mmol) of anhydrous FeCl3 was added to 30 ml of dichloromethane solution containing 3.16 g (10.0 mmol) of 9,9'-spirobifluorene. A solution of 2.1 ml (41 mmol) of bromine dissolved in 5 ml of dichloromethane was added slowly and dropwise over 10 min. The reaction mixture was refluxed for 6 hours. After completion of the reaction, it was cooled to room temperature and the product precipitated as a precipitate. The precipitate was collected by diafiltration and washed with a small amount of cold dichloromethane. Drying gave 6.0 g (95% yield) of the target product 2,2',7,7'-tetrabromo-9,9'-spirobifluorene as a white solid.

References

[1] Journal of the American Chemical Society, 1990, vol. 112, # 14, p. 5662 - 5663
[2] Journal of Organic Chemistry, 1996, vol. 61, # 20, p. 6906 - 6921
[3] Inorganic Chemistry, 2018, vol. 57, # 11, p. 6210 - 6213
[4] Journal of Materials Chemistry A, 2016, vol. 4, # 22, p. 8750 - 8754
[5] Chemistry - An Asian Journal, 2017, vol. 12, # 2, p. 181 - 189