4′-Heptyl-4-biphenylcarbonitrile (7CB, CAS 41122-71-8) is a thermotropic nematic liquid crystal from the cyanobiphenyl family, used in optical electronics research such as liquid-crystal displays (LCDs). Its molecule is a 1,1'-biphenyl core carrying a cyano group and a heptyl chain at the 4,4'-positions. It is supplied as a white powder or crystals with >98% purity by 1H NMR, a melting point of 36.0 °C and a mesomorphic range of 27.0 to 45.0 °C.
7CB is a common host matrix in nanocomposite studies. Carbon quantum dots dispersed in it have been reported to quench photoluminescence and lower UV–Vis absorbance at shorter wavelengths, while multiwalled carbon nanotubes can markedly alter its dielectric behaviour.
In perovskite solar cells, 7CB interacts with PbI2 to guide crystal growth orientation, giving fine, oriented domains that aid electron transport and stability. Reported devices rose in power conversion efficiency from 17.14% to 20.19% with a fill factor above 80%, and kept 92% of initial efficiency after 500 h at 25 °C and 70% relative humidity.
- Nematic liquid crystal material for LCD and optical electronics research.
- Additive for controlling perovskite crystal orientation to improve solar cell efficiency and stability.
- Host matrix for studying optical properties of dispersed carbon quantum dots.
- Matrix for investigating dielectric changes induced by multiwalled carbon nanotubes.
| Brand | Ossila |
|---|---|
| CAS number | 41122-71-8 |
| Molecular formula | C20H23N |
| Purity | >98% (1HNMR) |
| Category | — |
| Pack sizes | 5 g, 10 g, 25 g |
| Physical form | White powder/crystals |
| Storage | — |
- Product code: M2359A1
- Molecular Weight: 277.40
- Synonyms: 7CB, 4-Cyano-4'-heptylbiphenyl, 4'-Heptyl-4-biphenylcarbonitrile
- Classification / Family: Biphenylcarbonitrile, Nematic Liquid Crystals
- Mesomorphic Range: 27.0 to 45.0 °C
- Melting Point: Tm = 36.0 °C
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