Synthesis and Characterization of Ferrocene and Acetylferrocene

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Synthesis and Characterization of Ferrocene and
Acetylferrocene

• Sarah L. Wood
• Chemistry 351

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Background of Ferrocene
I. UH OH! Ferrocene - C5H5FeC5H5 A. Kealy and
Pauson 19511 B. 2C5H5MgBr FeCl2 ?
C5H5FeC5H5 MgBr2 MgCl2 C. Wilkinson,
Roseblum, Whiting, and Woodward2 D. sandwich
compound i.e. metallocene
Picture is courtesy of http//encyclopedia.thefre
edictionary.com/Ferrocene
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Background of Ferrocene

• Welcome organotransition metal chemistry
• A. First example of Cyclopentadienyl Complex, Cp
  3
• B. Cp group is used as stabilizing ligand3
• C. Led to better methods of synthesis
• D. Thousands of Cp complexes have since been
  synthesized3

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Background of Ferrocene

• Characteristics of Ferrocene
• A. orange coloration
• B. needle-like crystals
• C. Stability to water, air, and acid2
• D. Ease of sublimation
• E. Ease of acetylation 106 more likely than
  Benzene4

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Background of Friedel-Crafts Acetylation

• I. Reaction of an aromatic hydrocarbon with an
  acyl halide.5
• Ex

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Background of Friedel-Crafts Acetylation

• Ferrocene
• A. has been referred to as superaromatic
  compound3
• B. acetylated under milder conditions
  phosphoric acid4

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The Acetylation Note I only got the
monoacetylated
Picture courtesy of http//cas.bellarmine.edu/che
m117a/lab/Ferrocene.htm
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Background of Acetylferrocene

• Characteristics of Acetylferrocene
• C12H12FeO
• Lighter orange color
• Thicker crystals
• Stable
• Since acyl group is deactivating, only a little
  product is diacetylated3

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Methods

• Cyclopentadiene Synthesis
• Dicyclopentadiene dimer cracked
• Problems
• Courage doesnt always roar. Sometimes courage
  is the quiet voice at the end of the day saying,
  I will try again tomorrow. Mary Anne Radmacher

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Methods

• Ferrocene Synthesis
• A. Grind KOH and FeCl2H2O
• B. 100-mL 3 neck round bottom
• 1. 14.587 g of KOH
• 2. 30 mL of 1, 2- Dimethoxyethane
• 3. 3.0 mL of cyclopentadiene
• C. Pressure Equalizing Dropping Funnel
• 1. 12.5 mL of DMSO
• 2. 3.239 g FeCl2H2O
• D. 41.5 mL of 6 M HCl and 49.45 grams of ice
• E. Suction filtration
• F. Cold finger

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Methods

• Acetylferrocene Synthesis
• 10-mL round bottom flask
• 299.3 g ferrocene
• 6 drops 85 phosphoric acid
• Heated
• 4.0418 g ice added
• Neutralized by NaHCO3
• Suction Filtration

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Methods

• Product Separation
• Erlenmeyer Flask
• Dry solid
• 4 mL hexanes
• Modified Steam Bath
• Decanted and colorizing charcoal added
• Filtered
• Cooled
• Filtered, collected, and rinsed with cool solvent

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Characterization

• Melting Point (degrees Celsius)
• A. Ferrocene
• 1. Experimental 171.2 173.3
• 2. Literature 172 174 8
• B. Acetylferrocene
• 1. Experimental 69.9
• 2. Literature 85 -86 8

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Characterization

• Infrared Spectroscopy (IR)
• A. Solvent Hexanes
• B. Range Shown 1700 -2300 cm-1
• C. Ferrocene
• 1. no peaks
• D. Acetylferrocene
• 1. peak at 1684.89 cm-1
• 2. literature confirms correct region for CO
  in carbonyl group6

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Characterization
III. Gas Chromatograph Mass Spectroscopy (GC mass
spec) A. Solvent chloroform-d B.
Ferrocene 1. 186 ferrocene 2. 121 loss
of Cp ring 3. 56 loss of both Cp rings
atomic weight of Fe C. Acetylferrocene 1.
228 acetylferrocene 2. 213 loss of
CH3 3. 185 loss of CO ferrocene minus one
hydrogen 4. 129 appears to be two Cp
rings 5. 121 - loss of one Cp ring 6. 71
iron CH3 7. 56 loss of both Cp rings
atomic weight of Fe 8. 43 COCH3
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Characterization

• Ultraviolet Spectroscopy (UV vis)
• Solvent hexanes
• Ferrocene
• Absorbance maxima at 440.97 and 325.02 nm
• Literature shows 440 and 325!7
• Acetylferrocene
• Absorbance maxima at 446.03 and 319.07 nm
• Literature shows 320, but the 446.03 is due to
  the ferrocene impurities in the sample.7

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Characterization

• 1H-Nuclear Magnetic Resonance Spectroscopy
  (1H-NMR)
• A. Solvent chloroform-d
• Ferrocene
• 1. 7.2935 - solvent
• 2. 4.2199 Cp rings all same3
• 3. 1.5805, 1.4616 impurities
• Acetylferrocene
• 1. 7.2947 solvent
• 2. 4.1941, 4.2428, 4.5411 Cp rings and acetyl
  group3
• 3. several from 0.10 1.60 probably impurities

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Characterization

• 13C-Nuclear Magnetic Resonance Spectroscopy
  (13C-NMR)
• Solvent chloroform-d
• Ferrocene
• Several between 76 and 78 solvent
• 68.178 Cp rings
• Acetylferrocene
• 1. Several between 76 and 78 solvent
• 2. 69.640, 69.899, and 72.379 Cp rings and
  acetyl group
• 3. 27.470 methyl group3

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Conclusion

• Ferrocene synthesized
• Acetylferrocene synthesized
• Melting Point
• IR
• GC mass spec
• UV vis
• 1H-NMR
• 13C-NMR

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Future Work

• Larger Product Yields
• Get acetylation off microscale
• Complete Separation of products
• More efficient cracking column

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References

• Jolly, William L. The Synthesis and
  Characterization of Inorganic Compounds.
  Prentice-Hall, Inc Englewood Cliffs, NJ. 1970.
  pg. 4-5,407,484-487.
• 2. Williamson, Kenneth L. Organic Experiments
  Ninth Edition. Houghton Mifflin Company
  Boston, MA. 2004. pg. 352-353,502-506.
• 3. "Friedel-Crafts Acylation of Ferrocene".
• http//cas.bellarmine.edu/chem117a/lab/Ferrocene.
  htm. (accessed 29 January 2005)
• 4. Szafran, Pike, Singh. Microscale Inorganic
  Chemistry A Comprehensive Laboratory
  Experience. John Wiley Sons, Inc. New York.
  1991. pg. 302.
• 5. Brown, William H., Foote, Christopher S.
  Organic Chemistry Third Edition. Thomson
  Learning, Inc. 2002. pg. 810-811.
• 5. Wade, Leroy G. J. Chem. Educ. 1978, 55, 208.
• 6. Field, Sternhell, Kalman. Organic Structures
  from Spectra Third Edition. John Wiley Sons,
  Ltd. Hoboken, NJ. 2002.
• 7. Tanner, Pamela S. Jones Jr., Wayne E. Myers,
  Clifford E. Whittingham, Stanley M. Presented
  at the 210th National Meeting of the American
  Chemical Society, Chicago, Il, August 1995
  paper CHED 51. http//imr.chem.binghamton.edu/lab
  s/ferrocene/ferrocene.html (accessed January
  2005)