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Fluorene

October 17, 2023

Not to be confused with Fluorane, Fluorine, Fluorone, or Fluorenone.

Fluorene /ˈflʊəriːn/, or 9H-fluorene is an organic compound with the formula (C6H4)2CH2. It forms white crystals that exhibit a characteristic, aromatic odor similar to that of naphthalene. It has a violet fluorescence, hence its name. For commercial purposes it is obtained from coal tar.[3] It is insoluble in water and soluble in many organic solvents. Although sometimes classified as a polycyclic aromatic hydrocarbon, the five-membered ring has no aromatic properties.[citation needed] Fluorene is mildly acidic.

Fluorene[1]
Names
Preferred IUPAC name
9H-Fluorene[2]
Systematic IUPAC name
Tricyclo[7.4.0.02,7]trideca-2,4,6,9,11,13-hexaene
Identifiers
  • 86-73-7 Y
3D model (JSmol)
  • Interactive image
ChEBI
  • CHEBI:28266 Y
ChEMBL
  • ChEMBL16236 Y
ChemSpider
  • 6592 Y
ECHA InfoCard 100.001.541
EC Number
  • 201-695-5
KEGG
  • C07715 Y
  • 6853
RTECS number
  • LL5670000
UNII
  • 3Q2UY0968A Y
  • DTXSID8024105
  • InChI=1S/C13H10/c1-3-7-12-10(5-1)9-11-6-2-4-8-13(11)12/h1-8H,9H2 Y
    Key: NIHNNTQXNPWCJQ-UHFFFAOYSA-N Y
  • InChI=1/C13H10/c1-3-7-12-10(5-1)9-11-6-2-4-8-13(11)12/h1-8H,9H2
    Key: NIHNNTQXNPWCJQ-UHFFFAOYAW
  • c1ccc2c3ccccc3Cc2c1
Properties
C13H10
Molar mass 166.223 g·mol−1
Density 1.202 g/mL
Melting point 116 to 117 °C (241 to 243 °F; 389 to 390 K)
Boiling point 295 °C (563 °F; 568 K)
1.992 mg/L
Solubility organic solvents
log P 4.18
Acidity (pKa) 22.6
-110.5·10−6 cm3/mol
Hazards
NFPA 704 (fire diamond)
Health 1: Exposure would cause irritation but only minor residual injury. E.g. turpentineFlammability 1: Must be pre-heated before ignition can occur. Flash point over 93 °C (200 °F). E.g. canola oilInstability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazards (white): no code
1
1
0
Flash point 152 °C (306 °F; 425 K)
Lethal dose or concentration (LD, LC):
16000 mg/kg (oral, rat)
Safety data sheet (SDS) Sigma-Aldrich
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Y verify (what is YN ?)

Synthesis, structure, and reactivity Edit

Although fluorene is obtained from coal tar, it can also be prepared by dehydrogenation of diphenylmethane.[3] Alternatively, it can be prepared by the reduction of fluorenone with zinc[4] or hypophosphorous acid–iodine.[5] The fluorene molecule is nearly planar,[6] although each of the two benzene rings is coplanar with the central carbon 9.[7]

Fluorene can be found after the incomplete combustion of plastics such as PS, PE and PVC.[8]

Acidity Edit

The C9-H sites of the fluorene ring are weakly acidic (pKa = 22.6 in DMSO.[9]) Deprotonation gives the stable fluorenyl anion, nominally C13H9−, which is aromatic and has an intense orange colour. The anion is a nucleophile. Electrophiles react with it by adding to the 9-position. The purification of fluorene exploits its acidity and the low solubility of its sodium derivative in hydrocarbon solvents.

Both protons can be removed from C9. For example, 9,9-fluorenyldipotassium can be obtained by treating fluorene with potassium metal in boiling dioxane.[10]

Ligand properties Edit

Fluorene and its derivatives can be deprotonated to give ligands akin to cyclopentadienide.

 
A fluorenyl-derived Kaminsky precatalyst for producing syndiotactic polypropylene.[11]

Uses Edit

Fluorene is a precursor to other fluorene compounds; the parent species has few applications. Fluorene-9-carboxylic acid is a precursor to pharmaceuticals. Oxidation of fluorene gives fluorenone, which is nitrated to give commercially useful derivatives. 9-Fluorenylmethyl chloroformate (Fmoc chloride) is used to introduce the 9-fluorenylmethyl carbamate (Fmoc) protecting group on amines in peptide synthesis.[3]

Polyfluorene polymers (where carbon 7 of one unit is linked to carbon 2 of the next one, displacing two hydrogens) are electrically conductive and electroluminescent, and have been much investigated as a luminophore in organic light-emitting diodes.

Fluorene dyes Edit

Fluorene dyes are well developed. Most are prepared by condensation of the active methylene group with carbonyls. 2-Aminofluorene, 3,6-bis-(dimethylamino)fluorene, and 2,7-diiodofluorene are precursors to dyes.[12]

See also Edit

References Edit

  1. ^ Merck Index, 11th Edition, 4081
  2. ^ International Union of Pure and Applied Chemistry (2014). Nomenclature of Organic Chemistry: IUPAC Recommendations and Preferred Names 2013. The Royal Society of Chemistry. p. 207. doi:10.1039/9781849733069. ISBN 978-0-85404-182-4.
  3. ^ a b c Griesbaum, Karl; Behr, Arno; Biedenkapp, Dieter; Voges, Heinz-Werner; Garbe, Dorothea; Paetz, Christian; Collin, Gerd; Mayer, Dieter; Höke (2000). "Hydrocarbons". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a13_227.
  4. ^ Fittig, Rud. (1873), "Ueber einen neuen Kohlenwasserstoff aus dem Diphenylenketon" Ber. Dtsch. Chem. Ges. volume 6, p. 187.doi:10.1002/cber.18730060169
  5. ^ Hicks, Latorya D.; Han, Ja Kyung; Fry, Albert J. (2000). "Hypophosphorous acid–iodine: a novel reducing system". Tetrahedron Letters. Elsevier BV. 41 (41): 7817–7820. doi:10.1016/s0040-4039(00)01359-9. ISSN 0040-4039.
  6. ^ D. M. Burns, John Iball (1954), Molecular Structure of Fluorene Nature volume 173, p. 635. doi:10.1038/173635a0
  7. ^ Gerkin, R. E.; Lundstedt, A. P.; Reppart, W. J. (1984). "Structure of fluorene, C13H10, at 159 K". Acta Crystallographica Section C Crystal Structure Communications. 40 (11): 1892–1894. doi:10.1107/S0108270184009963.
  8. ^ Wang, Zhenlei; Richter, Henning; Howard, Jack B.; Jordan, Jude; Carlson, Joel; Levendis, Yiannis A. (2004-06-01). "Laboratory Investigation of the Products of the Incomplete Combustion of Waste Plastics and Techniques for Their Minimization". Industrial & Engineering Chemistry Research. 43 (12): 2873–2886. doi:10.1021/ie030477u. ISSN 0888-5885.
  9. ^ F. G. Bordwell (1988). "Equilibrium acidities in dimethyl sulfoxide solution". Acc. Chem. Res. 21 (12): 456–463. doi:10.1021/ar00156a004.
  10. ^ G. W. Scherf; R. K. Brown (1960). "Potassium Derivatives of Fluorene as Intermediates in the Preparation of C9-substituted Fluorenes. I. The Preparation of 9-fluorenyl Potassium and the Infrared Spectra of Fluorene and Some C9-substituted Fluorenes". Canadian Journal of Chemistry. 38: 697. doi:10.1139/v60-100..
  11. ^ Ewen, J. A.; Jones, R. L.; Razavi, A.; Ferrara, J. D. (1988). "Syndiospecific Propylene Polymerizations with Group IVB Metallocenes". Journal of the American Chemical Society. 110 (18): 6255–6256. doi:10.1021/ja00226a056. PMID 22148816.
  12. ^ Kurdyukova, I. V.; Ishchenko, A. A. (2012). "Organic dyes based on fluorene and its derivatives". Russian Chemical Reviews. 81 (3): 258–290. Bibcode:2012RuCRv..81..258K. doi:10.1070/RC2012v081n03ABEH004211.

External links Edit

  • Fluorene in the National Institute of Standards and Technology database.

October 17, 2023
fluorene, confused, with, fluorane, fluorine, fluorone, fluorenone, ʊər, fluorene, organic, compound, with, formula, c6h4, 2ch2, forms, white, crystals, that, exhibit, characteristic, aromatic, odor, similar, that, naphthalene, violet, fluorescence, hence, nam. Not to be confused with Fluorane Fluorine Fluorone or Fluorenone Fluorene ˈ f l ʊer iː n or 9H fluorene is an organic compound with the formula C6H4 2CH2 It forms white crystals that exhibit a characteristic aromatic odor similar to that of naphthalene It has a violet fluorescence hence its name For commercial purposes it is obtained from coal tar 3 It is insoluble in water and soluble in many organic solvents Although sometimes classified as a polycyclic aromatic hydrocarbon the five membered ring has no aromatic properties citation needed Fluorene is mildly acidic Fluorene 1 NamesPreferred IUPAC name 9H Fluorene 2 Systematic IUPAC name Tricyclo 7 4 0 02 7 trideca 2 4 6 9 11 13 hexaeneIdentifiersCAS Number 86 73 7 Y3D model JSmol Interactive imageChEBI CHEBI 28266 YChEMBL ChEMBL16236 YChemSpider 6592 YECHA InfoCard 100 001 541EC Number 201 695 5KEGG C07715 YPubChem CID 6853RTECS number LL5670000UNII 3Q2UY0968A YCompTox Dashboard EPA DTXSID8024105InChI InChI 1S C13H10 c1 3 7 12 10 5 1 9 11 6 2 4 8 13 11 12 h1 8H 9H2 YKey NIHNNTQXNPWCJQ UHFFFAOYSA N YInChI 1 C13H10 c1 3 7 12 10 5 1 9 11 6 2 4 8 13 11 12 h1 8H 9H2Key NIHNNTQXNPWCJQ UHFFFAOYAWSMILES c1ccc2c3ccccc3Cc2c1PropertiesChemical formula C 13H 10Molar mass 166 223 g mol 1Density 1 202 g mLMelting point 116 to 117 C 241 to 243 F 389 to 390 K Boiling point 295 C 563 F 568 K Solubility in water 1 992 mg LSolubility organic solventslog P 4 18Acidity pKa 22 6Magnetic susceptibility x 110 5 10 6 cm3 molHazardsNFPA 704 fire diamond 110Flash point 152 C 306 F 425 K Lethal dose or concentration LD LC LD50 median dose 16000 mg kg oral rat Safety data sheet SDS Sigma AldrichExcept 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 Synthesis structure and reactivity 1 1 Acidity 1 2 Ligand properties 2 Uses 2 1 Fluorene dyes 3 See also 4 References 5 External linksSynthesis structure and reactivity EditAlthough fluorene is obtained from coal tar it can also be prepared by dehydrogenation of diphenylmethane 3 Alternatively it can be prepared by the reduction of fluorenone with zinc 4 or hypophosphorous acid iodine 5 The fluorene molecule is nearly planar 6 although each of the two benzene rings is coplanar with the central carbon 9 7 Fluorene can be found after the incomplete combustion of plastics such as PS PE and PVC 8 Acidity Edit The C9 H sites of the fluorene ring are weakly acidic pKa 22 6 in DMSO 9 Deprotonation gives the stable fluorenyl anion nominally C13H9 which is aromatic and has an intense orange colour The anion is a nucleophile Electrophiles react with it by adding to the 9 position The purification of fluorene exploits its acidity and the low solubility of its sodium derivative in hydrocarbon solvents Both protons can be removed from C9 For example 9 9 fluorenyldipotassium can be obtained by treating fluorene with potassium metal in boiling dioxane 10 Ligand properties Edit Fluorene and its derivatives can be deprotonated to give ligands akin to cyclopentadienide nbsp A fluorenyl derived Kaminsky precatalyst for producing syndiotactic polypropylene 11 Uses EditFluorene is a precursor to other fluorene compounds the parent species has few applications Fluorene 9 carboxylic acid is a precursor to pharmaceuticals Oxidation of fluorene gives fluorenone which is nitrated to give commercially useful derivatives 9 Fluorenylmethyl chloroformate Fmoc chloride is used to introduce the 9 fluorenylmethyl carbamate Fmoc protecting group on amines in peptide synthesis 3 Polyfluorene polymers where carbon 7 of one unit is linked to carbon 2 of the next one displacing two hydrogens are electrically conductive and electroluminescent and have been much investigated as a luminophore in organic light emitting diodes Fluorene dyes Edit Fluorene dyes are well developed Most are prepared by condensation of the active methylene group with carbonyls 2 Aminofluorene 3 6 bis dimethylamino fluorene and 2 7 diiodofluorene are precursors to dyes 12 See also EditCataCXium F sulf Fluorenol Indecainide PD 137889References Edit Merck Index 11th Edition 4081 International Union of Pure and Applied Chemistry 2014 Nomenclature of Organic Chemistry IUPAC Recommendations and Preferred Names 2013 The Royal Society of Chemistry p 207 doi 10 1039 9781849733069 ISBN 978 0 85404 182 4 a b c Griesbaum Karl Behr Arno Biedenkapp Dieter Voges Heinz Werner Garbe Dorothea Paetz Christian Collin Gerd Mayer Dieter Hoke 2000 Hydrocarbons Ullmann s Encyclopedia of Industrial Chemistry Weinheim Wiley VCH doi 10 1002 14356007 a13 227 Fittig Rud 1873 Ueber einen neuen Kohlenwasserstoff aus dem Diphenylenketon Ber Dtsch Chem Ges volume 6 p 187 doi 10 1002 cber 18730060169 Hicks Latorya D Han Ja Kyung Fry Albert J 2000 Hypophosphorous acid iodine a novel reducing system Tetrahedron Letters Elsevier BV 41 41 7817 7820 doi 10 1016 s0040 4039 00 01359 9 ISSN 0040 4039 D M Burns John Iball 1954 Molecular Structure of Fluorene Nature volume 173 p 635 doi 10 1038 173635a0 Gerkin R E Lundstedt A P Reppart W J 1984 Structure of fluorene C13H10 at 159 K Acta Crystallographica Section C Crystal Structure Communications 40 11 1892 1894 doi 10 1107 S0108270184009963 Wang Zhenlei Richter Henning Howard Jack B Jordan Jude Carlson Joel Levendis Yiannis A 2004 06 01 Laboratory Investigation of the Products of the Incomplete Combustion of Waste Plastics and Techniques for Their Minimization Industrial amp Engineering Chemistry Research 43 12 2873 2886 doi 10 1021 ie030477u ISSN 0888 5885 F G Bordwell 1988 Equilibrium acidities in dimethyl sulfoxide solution Acc Chem Res 21 12 456 463 doi 10 1021 ar00156a004 G W Scherf R K Brown 1960 Potassium Derivatives of Fluorene as Intermediates in the Preparation of C9 substituted Fluorenes I The Preparation of 9 fluorenyl Potassium and the Infrared Spectra of Fluorene and Some C9 substituted Fluorenes Canadian Journal of Chemistry 38 697 doi 10 1139 v60 100 Ewen J A Jones R L Razavi A Ferrara J D 1988 Syndiospecific Propylene Polymerizations with Group IVB Metallocenes Journal of the American Chemical Society 110 18 6255 6256 doi 10 1021 ja00226a056 PMID 22148816 Kurdyukova I V Ishchenko A A 2012 Organic dyes based on fluorene and its derivatives Russian Chemical Reviews 81 3 258 290 Bibcode 2012RuCRv 81 258K doi 10 1070 RC2012v081n03ABEH004211 External links EditFluorene in the National Institute of Standards and Technology database Retrieved from https en wikipedia org w index php title Fluorene amp oldid 1180468788, wikipedia, wiki, book, books, library,

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