4′-Octyloxy-4-biphenylcarbonitrile, commonly known as 8OCB (CAS 52364-73-5), is a liquid crystal material showing nematic and smectic A phases, intended for optical electronics work such as liquid-crystal displays (LCDs). It is a member of the 4-oxy-4'-cyanobiphenyl (OCB) family, built on a biphenyl core carrying an octyloxy group and a cyano group at the 4,4'-positions. Ossila supplies it as a white powder or crystals with purity above 98% by 1H NMR.
On heating from the crystal, 8OCB passes through three transitions: crystalline to smectic A at 52.86 °C, smectic A to nematic at 66.65 °C, and nematic to isotropic at 79.10 °C. In the solid state the molecules arrange into lamellar bilayers held by hydrogen bonding from the CN group, and several crystal polymorphs have been reported from solution and from the melt.
8OCB has also been studied as an additive in organic solar cells. Adding 6 wt% of the nematic liquid crystal to a P3HT:PC60BM active layer, then annealing at 70 °C, helped template P3HT crystallization and phase separation, giving a maximum PCE of 3.5%.
- Research on liquid-crystal displays and other optical electronic devices.
- Studies of phase transitions and crystal polymorphism in cyanobiphenyl liquid crystals.
- Preparation of binary 8CB/8OCB liquid crystal mixtures for thermal and spectrophotometric analysis.
- Use as a nematic liquid crystal additive to improve morphology in P3HT:PC60BM organic photovoltaic active layers.
| Brand | Ossila |
|---|---|
| CAS number | 52364-73-5 |
| Molecular formula | C21H25NO |
| Purity | >98% (1HNMR) |
| Category | — |
| Pack sizes | 5 g, 10 g, 25 g |
| Physical form | White powder/crystals |
| Storage | — |
- Product code: M2360A1
- Molecular Weight: 307.43
- Synonym: 8OCB
- Classification / Family: Biphenylcarbonitrile, Liquid Crystals
- Melting Point: Tm = 54 °C
- Crystalline–smectic A transition: TCrA = 52.86 °C
- Smectic A–nematic transition: TAN = 66.65 °C
- Nematic–isotropic transition: TNI = 79.10 °C
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