“4-Cyano-4'-pentylbiphenyl”的意思、由来-开放百科全书

词条

4-Cyano-4'-pentylbiphenyl

释义

Production
Notes
References
External links

{{chembox
| Verifiedfields = changed
| Watchedfields = changed
| verifiedrevid = 477221399
| ImageFile1 = 4-Cyano-4'-pentylbiphenyl.svg
| ImageSize1 = 260px
| ImageAlt1 = Skeletal formula of 4-cyano-4'-pentylbiphenyl
| ImageFile2 = 4-Cyano-4'-pentylbiphenyl molecule planar spacefill.png
| ImageSize2 = 210
| ImageAlt2 = Space-filling model of the 4-cyano-4'-pentylbiphenyl molecule
| OtherNames = 4'-Amyl-4-biphenylcarbonitrile, 4'-Pentyl-4-biphenylcarbonitrile, 4-Amyl-4'-cyanobiphenyl
|Section1={{Chembox Identifiers
| SMILES = N#Cc2ccc(c1ccc(cc1)CCCCC)cc2
| InChIKey = HHPCNRKYVYWYAU-UHFFFAOYAV
| StdInChI_Ref = {{stdinchicite|changed|chemspider}}
| StdInChI = 1S/C18H19N/c1-2-3-4-5-15-6-10-17(11-7-15)18-12-8-16(14-19)9-13-18/h6-13H,2-5H2,1H3
| StdInChIKey_Ref = {{stdinchicite|changed|chemspider}}
| StdInChIKey = HHPCNRKYVYWYAU-UHFFFAOYSA-N
| CASNo = 40817-08-1
| PubChem = 92319
| EC_number = 255-093-2
| CASNo_Ref = {{cascite|changed|CAS}}
| ChemSpiderID_Ref = {{chemspidercite|changed|chemspider}}
| ChemSpiderID = 83347
| InChI = 1/C18H19N/c1-2-3-4-5-15-6-10-17(11-7-15)18-12-8-16(14-19)9-13-18/h6-13H,2-5H2,1H3
}}
|Section2={{Chembox Properties
| C=18 | H=19 | N=1
| Appearance = Colorless if isotropic or cloudy white if nematic
| Density = 1.008 g/mL
}}
|Section7={{Chembox Hazards
| ExternalSDS =
| NFPA-H = 2
| NFPA-F = 1
| NFPA-R = 0
| NFPA-S =
| GHSPictograms = {{GHS07}}
| GHSSignalWord = Warning
| HPhrases = {{H-phrases|302|312|315|319|332|335}}
| PPhrases = {{P-phrases|261|264|270|271|280|301+312|302+352|304+312|304+340|305+351+338|312|321|322|330|332+313|337+313|362|363|403+233|405|501}}
}}
}}4-Cyano-4'-pentylbiphenyl is a commonly used nematic liquid crystal with the chemical formula C₁₈H₁₉N. It frequently goes by the common name 5CB. 5CB was first synthesized by George William Gray, Ken Harrison, and J.A. Nash at the University of Hull in 1972 and at the time it was the first member of the cyanobiphenyls.^[1]^[2] The liquid crystal was discovered after Gray's group received a grant from the UK Ministry of Defence to find a liquid crystal that had liquid crystal phases near room temperature with the specific intention of using them in liquid crystal displays. The molecule is about 20 Å long. The liquid crystal 5CB undergoes a phase transition from a crystalline state to a nematic state at 24 °C and it goes from a nematic to an isotropic state at 35 °C.^[3]

Production

5CB is produced by modifying biphenyl in a linear manner. First Br₂ is added to the biphenyl to introduce a bromine atom to the end of the moiety. Next aluminium chloride and C₄H₉COCl is added to the sample, followed by the addition of potassium hydroxide and NH₂NH₂. By this point the molecule will have a bromine atom on one end of the rigid core and C₅H₁₁ on the other end. Finally, introduction of copper(I) cyanide and DMF results in the removal of the bromine and its replacement with CN, yielding 5CB.^[4]

Notes

1. ^{{harvnb|Gray|Harrison|Nash|1973|pp=130–131}}
2. ^{{harvnb|Collings|Hird|1997|p=53}}
3. ^{{Cite news|url=https://www.techniques-ingenieur.fr/base-documentaire/materiaux-th11/materiaux-actifs-et-intelligents-42126210/cristaux-liquides-a1325/|title=Cristaux liquides|last=BAROIS|first=Philippe|date=1996-02-10|work=Techniques de l'Ingénieur|page=5|language=fr-FR}}
4. ^{{harvnb|Collings|Hird|1997|pp=151–152}}

References

Barois, Philippe (1996). Cristaux liquides. Techniques de l'ingénieur. ref. article : a1325.
{{cite book | last1=Collings | first1=Peter J. | editor1-first= George William | editor1-last= Gray | editor1-link= George William Gray | editor2-first= J. W. | editor2-last= Goodby | editor3-first= A. | editor3-last= Fukuda | ref=harv | authorlink1= | last2= Hird | first2= Michael | year= 1997 | title= Introduction to Liquid Crystals: Chemistry and Physics | publisher = Taylor and Francis Ltd. | isbn = 0-7484-0643-3 }}
{{cite journal | last1=Gray | first1=George William | authorlink1= George William Gray | journal=Liquid Crystals | volume=24 | issue=1 |date=January 1998 | pages=5–14 | title= Reminiscences from a life with liquid crystals | doi=10.1080/026782998207523 }}
{{cite journal | last1=Gray | first1=George William | authorlink1= George William Gray | last2=Harrison | first2=Ken J. | last3=Nash | first3=J A. | journal=Electronics Letters | volume=9 | number=6 | pages=130–131 | title= New family of nematic liquid crystals for displays | year=1973 | ref=harv | doi=10.1049/el:19730096}}
{{cite journal | last1=Seo | first1=D. S. | authorlink1= | last2=Matsuda | first2=H. | last3=Oh-Ide | first3=T. | last4=Kobayashi | first4= S. | journal=Molecular Crystals and Liquid Crystals | volume=224 | issue=1 | pages=13–31 | title= Alignment of Nematic Liquid Crystal(5CB) on the Treated Substrates: Characterization of Orientation Films, Generation of Pretilt Angles, and Surface Anchoring Strength | year=1993 | doi=10.1080/10587259308032475 }}
{{cite journal | last1=Vill | first1=Volkmar | authorlink1= | journal=Liquid Crystals | volume=24 | issue=1 |date=January 1998 | pages=21–24 | title= Grey levels in the history of liquid crystals | doi=10.1080/026782998207541 }}

External links

Space Filling Model of 5CB
{{cite web |url=http://mraths.org.uk/?page_id=576 |title=Liquid Crystal Displays (1973-1982) |publisher=Malvern Radar and Technology History Society |year=2016}}

3 : Liquid crystals|Liquid crystal displays|Nitriles

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