4CzBN, or 2,3,5,6-tetrakis(carbazol-9-yl)benzonitrile (CAS 1996609-93-8), is a sky-blue emitter that works by thermally activated delayed fluorescence (TADF). It is supplied as a sublimed material with purity above 99.0% by 1H NMR, appearing as a lime-yellow powder or crystals, and is intended for organic light-emitting diode (OLED) research.
The molecule is built on a benzonitrile core carrying four bulky carbazolyl groups spread evenly around the ring beside the nitrile group. Although no bulky group sits at the 4-position, the carbazolyl units at the 3- and 5-positions are still twisted. With one nitrile group fewer than the symmetric, non-polar 4CzTPN, 4CzBN shows a lower charge carrier balance.
In toluene it absorbs at 334 nm and 403 nm and emits at 443 nm. Reported energy levels are HOMO 5.79 eV, LUMO 2.75 eV and T1 2.66 eV. In a reported device using 15 wt.% 4CzBN in mCBP, sky-blue emission reached a maximum current efficiency of 26.6 cd/A, EQE of 9.7% and power efficiency of 20.9 lm/W.
- Sky-blue TADF emitter in the emissive layer of OLED devices.
- Blue dopant doped into host materials such as mCBP for OLED research.
- Study of carbazole-benzonitrile TADF materials and their excited-state behaviour.
- Optical absorption and fluorescence measurements with an optical spectrometer.
| Brand | Ossila |
|---|---|
| CAS number | 1996609-93-8 |
| Molecular formula | C55H33N5 |
| Purity | Sublimed >99.0% (1H NMR) |
| Category | — |
| Pack sizes | — |
| Physical form | Lime-yellow powder/crystals |
| Storage | — |
- Product code: M2217A2
- Full name: 2,3,5,6-tetrakis(carbazol-9-yl)benzonitrile
- Molecular weight: 763.9 g/mol
- Absorption: λmax 334 nm, 403 nm in toluene
- Fluorescence: λem 443 nm in toluene
- HOMO/LUMO: HOMO = 5.79 eV, LUMO = 2.75 eV, T1 = 2.66 eV
- Thermal properties: Td = 455 °C (0.5% weight loss), Tg = 316 °C (lit.)
- Classification / Family: Carbazole, Phthalonitrile, TADF materials, Blue dopant materials, Sublimed materials
- Device emission color: Sky-blue
- Max. current efficiency: 26.6 cd/A
- Max. EQE: 9.7%
- Max. power efficiency: 20.9 lm/W
An MSDS sheet is available for 4CzBN; consult it for safe handling and storage.
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