pentafluorobenzene

{{Chembox

| ImageFile = Pentafluorobenzene.svg

| ImageSize = 200px

| ImageAlt =

| PIN = Pentafluorobenzene

| OtherNames = Pentafluorobenzene, phenyl pentafluoride

| Section1 = {{Chembox Identifiers

| CASNo = 363-72-4

| CASNo_Ref = {{cascite|correct|CAS}}

| UNII_Ref = {{fdacite|correct|FDA}}

| UNII = IH36LU53XS

| PubChem = 9696

| ChemSpiderID = 13866746

| EINECS = 206-658-7

| SMILES = C1=C(C(=C(C(=C1F)F)F)F)F

| StdInChI= 1S/C6HF5/c7-2-1-3(8)5(10)6(11)4(2)9/h1H

| StdInChIKey= WACNXHCZHTVBJM-UHFFFAOYSA-N

}}

| Section2 = {{Chembox Properties

| C=6|H=1|F=5

| Appearance = Colorless liquid

| Density = 1.511 g/cm³

| Solubility = Insoluble

| MeltingPtC = −47.4

| BoilingPtC = 85

| VaporPressure =

}}

| Section3 = {{Chembox Hazards

| MainHazards =

| GHSPictograms = {{GHS02}} {{GHS05}} {{GHS07}}

| GHSSignalWord = DANGER

| HPhrases = {{H-phrases|225|302|315|318|335}}

| PPhrases =

| FlashPtC = 14

| AutoignitionPt =

}}

}}

Pentafluorobenzene is a synthetic organofluoride compound with the molecular formula {{chem|C|6|H|F|5}}.{{cite web|title=Pentafluorobenzene|url=http://www.sigmaaldrich.com/catalog/product/aldrich/p5301?lang=en®ion=RU&gclid=Cj0KEQjw6-PJBRCO_br1qoOB4LABEiQAEkqcVZI5xErFDTYKmyXDPaZoi7a8XDWgAXiIZSrKwDGKvVsaAn_18P8HAQ|website=Sigma Aldrich|publisher=sigmaaldrich.com|accessdate=8 June 2017}} The compound consists of a benzene ring substituted with five fluorine atoms.{{cite web|title=Пентафторбензол|url=http://www.himreakt.ru/4102/|publisher=himreakt.ru|accessdate=8 June 2017|language=Russian}} The substance is a colorless liquid with a boiling point similar to that of benzene.{{cite web|title=Pentafluorobenzene|url=http://webbook.nist.gov/cgi/cbook.cgi?ID=363-72-4|website=NIST|publisher=webbook.nist.gov|accessdate=8 June 2017}}CRC Handbook of Chemistry and Physics, 90. Edition, CRC Press, Boca Raton, Florida, 2009, {{ISBN|978-1-4200-9084-0}}, Section 3, Physical Constants of Organic Compounds, p. 3-414.

It is prepared by defluorination of highly fluorinated cyclohexanes over hot nickel or iron.{{cite journal|doi=10.1038/183586a0|title=Thermal Reactions of Highly Fluorinated Cyclo Hexadienes|year=1959|last1=Gething|first1=B.|last2=Patrick|first2=C. R.|last3=Tatlow|first3=J. C.|last4=Banks|first4=R. E.|last5=Barbour|first5=A. K.|last6=Tipping|first6=A. E.|journal=Nature|volume=183|issue=4661|pages=586–587|bibcode=1959Natur.183..586G}} Another method involved dehydrofluorination of polyfluorinated cyclohexane using hot aqueous solution of potassium hydroxide.{{cite journal|doi=10.1039/JR9590000166|title=31. Aromatic polyfluoro-compounds. Part I. The synthesis of aromatic polyfluoro-compounds from pentafluorobenzene|year=1959|last1=Nield|first1=E.|last2=Stephens|first2=R.|last3=Tatlow|first3=J. C.|journal=Journal of the Chemical Society (Resumed)|pages=166}}

It has been observed as a degradation by-product of the incineration of polytetrafluoroethylene and of biosolids.{{cite journal |last1=Hakeem |first1=Ibrahim Gbolahan |last2=Halder |first2=Pobitra |last3=Patel |first3=Savankumar |last4=Selezneva |first4=Ekaterina |last5=Rathnayake |first5=Nimesha |last6=Marzbali |first6=Mojtaba Hedayati |last7=Veluswamy |first7=Ganesh |last8=Sharma |first8=Abhishek |last9=Kundu |first9=Sazal |last10=Surapaneni |first10=Aravind |last11=Megharaj |first11=Mallavarapu |last12=Batstone |first12=Damien J. |last13=Shah |first13=Kalpit |title=Current understanding on the transformation and fate of per- and polyfluoroalkyl substances before, during, and after thermal treatment of biosolids |journal=Chemical Engineering Journal |date=August 2024 |volume=493 |pages=152537 |doi=10.1016/j.cej.2024.152537|doi-access=free }}