As a product in the field of coal chemical industry, fluorene has been known to people for more than 100 years. In 1876, the Frenchman Berthelot, the discoverer of fluorene, separated and purified a new fluorescent flake compound in the laboratory and named it fluorene, which means fluorescent substance. After more than 100 years of development, fluorene and derivatives containing fluorene structure are widely used in pharmaceutical, aerospace, electronics and other industries.

Structural characteristics of fluorene

The chemical structure of fluorene is a special biphenyl structure, that is, there is a methylene group that fixes two benzene rings on a plane. Compared with general biphenyl, the structure has stronger rigidity, which also brings many other differences in properties, such as better thermal stability, larger conjugated absorption wavelength, more obvious photoluminescence (fluorescence and phosphorescence), electroluminescence phenomenon, These optical properties make fluorene derivatives widely used in the optoelectronic industry.

Photosensitive and photoconductive materials containing fluorene structure

Due to their special optical properties, compounds containing fluorene structure and their derivatives can be used to synthesize various functional compounds with photoconductive or photosensitive activity, and further made into photoconductive materials and photosensitive material devices.

1. Fluorene-triphenylamine structure compound: This functional compound is coated on a conductive substrate to form a photosensitive layer, which can be used in electrophotographic equipment. The modified photosensitive layer has excellent electrophotographic properties such as high sensitivity, repeated voltage stability, weakened transfer memory, no cracks in the photosensitive layer, and non-crystallization of charge transfer materials.

• Fluorene-azo structure compound: Photoconductive materials prepared with fluorene-azo structure compounds as raw materials are widely used in non-silver series and photosensitive materials. The imaging principle of this type of photosensitive material is: first charge the material, then expose the charged material to the image, the charge of the part that sees the light disappears, and the potential of the part that does not see the light is retained, and a permanent image is obtained by developing and fixing.

• Polyalkylfluorene and its derivatives: Polyalkylfluorene and its derivatives have high thermal and chemical stability because they contain a rigid in-plane biphenyl unit, and have a high fluorescence quantum yield in the solid state. As a chain conjugated polymer, polyalkylfluorene can be applied to the field of optoelectronic display devices. Under normal circumstances, polyalkylfluorene has a large band gap and is a blue-light-emitting material. This type of material is favored because it is one of the few blue-light-emitting diode materials.

• Fluorene-thiophene copolymer: If fluorene derivatives are copolymerized with some monomers with small band gaps, polymer materials with different luminescent colors can be obtained. Thiophene monomers and their derivatives are electron donors. The lone pair of electrons on the sulfur atom of the thiophene ring can provide electrons, which increases the electron cloud density on the polymer chain and reduces the band gap of the polymer. The steric hindrance between the thiophene ring and the benzene ring is smaller than that between the benzene rings, so the planarity between the benzene ring and the thiophene ring is stronger, which makes the conjugation of the polymer greater, and the spectrum of the polymer is red-shifted, which can achieve the adjustment of the color of the polyfluorene itself and the electroluminescent color.

• Fluorene-oxadiazole copolymer: In order to obtain a high-efficiency PLED device, it is very necessary to inject electrons and holes into the polymer light-emitting layer in a balanced manner. Conjugated polymers with high electron affinity have low electron injection barriers, while polymers with electron-withdrawing units in the main chain usually have higher electron affinity. Introducing oxadiazole units into the polymer chain is an effective method to improve the electron affinity and electron transport capacity of the polymer.

Daken Chemical focus on development and production of Fluorene derivative, the following is some of our products:

9,9-bis(6-hydroxy-2-naphthyl)fluorene CAS No.: 934557-66-1

9,9-bis (3-phenyl-4-hydroxy) phenyl fluorene CAS No.: 161256-84-4

9,9-Bis[4-(2-acryloyloxyethoxy)-3-phenylphenyl]fluorene CAS No.: 1193334-69-8

9,9-Bis[6-(2-acryloyloxyethoxy)-2-naphthyl]fluorene CAS No.: 1170946-19-6

9,9-Bis(6-glycidyloxy-2-naphthyl)fluorene CAS No.: 1238475-45-0

9,9-Bis(4-glycidyloxyphenyl)fluorene diacrylate 143182-97-2

9,9-Bis[4-(2-acryloyloxyethyloxy)phenyl]fluorene 161182-73-6

Ethoxylated 9,9-bis[4-hydroxyphenyl]fluorene diacrylate 917867-33-5

More products, please kindly reach out to us by emails: ellen.zhao@dakenchem.com