Fluorobenzene is the chemical compound with the formula C6H5F, often abbreviated PhF. A colorless liquid, it is a precursor to many fluorophenyl compounds.
PhF was first reported in 1886 by O. Wallach at the University of Bonn, who prepared the compound in two steps. Phenyldiazonium chloride was first converted to a triazene using piperidine:
According to the procedure, solid [PhN2]BF4 is heated with a flame to initiate an exothermic reaction, which also affords boron trifluoride and nitrogen gas. Product PhF and BF3 are readily separated because of their differing boiling points.[2]
PhF behaves rather differently from other halobenzene derivatives owing to the pi-donor properties of fluoride. For example, the para position is more activated than benzene toward electrophiles. For this reason, it can be converted to 1-bromo-4-fluorobenzene with relatively high efficiency.[3]
Solvent properties
Structure of [(C5Me5)2Ti(FC6H5)]+, a coordination complex of fluorobenzene.
PhF is a useful solvent for highly reactive species. Its melting point at -44 °C is lower than that of benzene. In contrast, the boiling points of PhF and benzene are very similar, differing by only 4 °C. It is considerably more polar than benzene, with a dielectric constant of 5.42 compared to 2.28 for benzene at 298 K.[4] Fluorobenzene is a relatively inert compound reflecting the strength of the C–F bond.
Although it is usually considered a non-coordinating solvent, a metal complex of PhF has been crystallized.[5]
^Wallach, O. "Über einen Weg zur leichten Gewinnung organischer Fluorverbindungen" (Concerning a method for easily preparing organic fluorine compounds) Justus Liebig's Annalen der Chemie, 1886, Volume 235, p. 255–271; doi:10.1002/jlac.18862350303
^Flood, D. T. (1933). "Fluorobenzene". Org. Synth. 13: 46. doi:10.15227/orgsyn.013.0046..
^Rosenthal, Joel; Schuster, David I. (2003). "The Anomalous Reactivity of Fluorobenzene in Electrophilic Aromatic Substitution and Related Phenomena". J. Chem. Educ. 80 (6): 679. Bibcode:2003JChEd..80..679R. doi:10.1021/ed080p679.
^Table of Dielectric Constants of Pure Liquids. National Bureau of Standards. 1951.
^R.N. Perutz and T. Braun "Transition Metal-mediated C–F Bond Activation" Comprehensive Organometallic Chemistry III, 2007, Volume 1, p. 725–758; doi:10.1016/B0-08-045047-4/00028-5.
August 25, 2023
fluorobenzene, chemical, compound, with, formula, c6h5f, often, abbreviated, colorless, liquid, precursor, many, fluorophenyl, compounds, structure, fluorobenzene, space, filling, model, fluorobenzenenamespreferred, iupac, name, other, names, phenyl, fluoridem. Fluorobenzene is the chemical compound with the formula C6H5F often abbreviated PhF A colorless liquid it is a precursor to many fluorophenyl compounds Fluorobenzene Structure of fluorobenzene Space filling model of fluorobenzeneNamesPreferred IUPAC name FluorobenzeneOther names Phenyl fluorideMonofluorobenzeneIdentifiersCAS Number 462 06 6 Y3D model JSmol Interactive imageBeilstein Reference 1236623ChEBI CHEBI 5115 YChEMBL ChEMBL16070 YChemSpider 9614 YECHA InfoCard 100 006 657EC Number 207 321 7Gmelin Reference 49856KEGG C11272 YPubChem CID 10008UNII G3TSZ68K12 YUN number 2387CompTox Dashboard EPA DTXSID4025329InChI InChI 1S C6H5F c7 6 4 2 1 3 5 6 h1 5H YKey PYLWMHQQBFSUBP UHFFFAOYSA N YInChI 1 C6H5F c7 6 4 2 1 3 5 6 h1 5HKey PYLWMHQQBFSUBP UHFFFAOYAMSMILES Fc1ccccc1PropertiesChemical formula C6H5FMolar mass 96 103Appearance Colorless liquidDensity 1 025 g mL liquidMelting point 44 C 47 F 229 K Boiling point 84 to 85 C 183 to 185 F 357 to 358 K Solubility in water lowMagnetic susceptibility x 58 4 10 6 cm3 molRefractive index nD 1 46553StructureMolecular shape PlanarHazardsGHS labelling PictogramsSignal word WarningHazard statements H225 H318 H411Precautionary statements P210 P233 P240 P241 P242 P243 P264 P273 P280 P303 P361 P353 P305 P351 P338 P310 P337 P313 P370 P378 P391 P403 P235 P501NFPA 704 fire diamond 130Related compoundsRelated halobenzenes ChlorobenzeneBromobenzeneIodobenzeneRelated compounds Benzene1 2 DifluorobenzeneExcept where otherwise noted data are given for materials in their standard state at 25 C 77 F 100 kPa Y verify what is Y N Infobox references Contents 1 Preparation 2 Reactions 3 Solvent properties 4 See also 5 ReferencesPreparation EditPhF was first reported in 1886 by O Wallach at the University of Bonn who prepared the compound in two steps Phenyldiazonium chloride was first converted to a triazene using piperidine PhN2 Cl 2 CH2 5NH PhN N N CH2 5 CH2 5NH2 ClThe triazine was then cleaved with hydrofluoric acid PhN N N CH2 5 2 HF PhF N2 CH2 5NH2 FHistorical note in Wallach s era the element fluorine was symbolized with Fl Thus his procedure is subtitled Fluorbenzol C6H5Fl 1 On the laboratory scale PhF is prepared by the thermal decomposition of the benzenediazonium tetrafluoroborate PhN2BF4 PhF BF3 N2According to the procedure solid PhN2 BF4 is heated with a flame to initiate an exothermic reaction which also affords boron trifluoride and nitrogen gas Product PhF and BF3 are readily separated because of their differing boiling points 2 The technical synthesis is by the reaction of cyclopentadiene with difluorocarbene The initially formed cyclopropane undergoes a ring expansion and subsequent elimination of hydrogen fluoride Reactions EditPhF behaves rather differently from other halobenzene derivatives owing to the pi donor properties of fluoride For example the para position is more activated than benzene toward electrophiles For this reason it can be converted to 1 bromo 4 fluorobenzene with relatively high efficiency 3 Solvent properties Edit Structure of C5Me5 2Ti FC6H5 a coordination complex of fluorobenzene PhF is a useful solvent for highly reactive species Its melting point at 44 C is lower than that of benzene In contrast the boiling points of PhF and benzene are very similar differing by only 4 C It is considerably more polar than benzene with a dielectric constant of 5 42 compared to 2 28 for benzene at 298 K 4 Fluorobenzene is a relatively inert compound reflecting the strength of the C F bond Although it is usually considered a non coordinating solvent a metal complex of PhF has been crystallized 5 See also EditBromobenzene Chlorobenzene IodobenzeneReferences Edit Wallach O Uber einen Weg zur leichten Gewinnung organischer Fluorverbindungen Concerning a method for easily preparing organic fluorine compounds Justus Liebig s Annalen der Chemie 1886 Volume 235 p 255 271 doi 10 1002 jlac 18862350303 Flood D T 1933 Fluorobenzene Org Synth 13 46 doi 10 15227 orgsyn 013 0046 Rosenthal Joel Schuster David I 2003 The Anomalous Reactivity of Fluorobenzene in Electrophilic Aromatic Substitution and Related Phenomena J Chem Educ 80 6 679 Bibcode 2003JChEd 80 679R doi 10 1021 ed080p679 Table of Dielectric Constants of Pure Liquids National Bureau of Standards 1951 R N Perutz and T Braun Transition Metal mediated C F Bond Activation Comprehensive Organometallic Chemistry III 2007 Volume 1 p 725 758 doi 10 1016 B0 08 045047 4 00028 5 Retrieved from https en wikipedia org w index php title Fluorobenzene amp oldid 1063289502, wikipedia, wiki, book, books, library,
