Organometallic Chemistry Introduction

1
Organometallic Chemistry Introduction
Textbook Introduction, History, Chapters 1.1 -
1.3
Discussion section / office hours Friday 4 5
pm after class

• Paula Diaconescu
• TA Kevin Miller
• E-mail pld_at_chem.ucla.edu klmiller_at_chem.ucla.edu

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Textbooks

• Required text
• Organometallic chemistry and catalysis by Didier
  Astruc, Springer, 2007
• UCLA subscription http//www.springerlink.com/con
  tent/r36568/
• Recommended
• Organometallics 1 Complexes with Metal-Carbon s
  Bonds and Organometallics 2 Complexes with
  Metal-Carbon p Bonds by Manfred Bochmann, Oxford
  University Press, 1993 (beginner level)
• Applied Organometallic Chemistry and Catalysis by
  Robin Whyman, Oxford University Press, 2003
  (beginner level)
• Organometallic Chemistry by Gary O. Spessard and
  Gary L. Miessler, Prentice Hall, Inc., 1997
  (intermediate level)
• The Organometallic Chemistry of the Transition
  Metals by Robert H. Crabtree, Wiley Interscience
  2nd edition 1994 or 3rd edition - 2005
  (advanced level)
• Homogeneous Catalysis Understanding the art by
  Piet W. N. M. van Leeuwen, Kluwer Academic
  Publishers, 2004 (advanced level)
• Article references given during lecture
• http//www.ilpi.com/organomet/index.html

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Grading

• Grading
• Midterm 1 20
• Midterm 2 20
• Final 40
• Literature presentation 20 (10 for content, 5
  for answering questions, 5 for asking questions)

Bonus 5 for writing a paper on a given topic
5 for writing an original proposal undergraduates
5 for attending all seminars listed below all
5 for asking at least 5 good questions during
the seminars listed below

• Winter organometallic seminars
• Tobias Ritter, Harvard University January 7
  (Organic seminar, 5pm)
• Xile Hu, EPF Lausanne January 27
• Aaron Sadow, Iowa State University February 3
• Cora McBeth, Emory University February 10
• Jun Okuda, RWTH Aachen University February 17
• John Gordon, Los Alamos National Laboratory,
  March 3

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Administrative details

• All lecture notes will be posted before class on
  http//vohweb.chem.ucla.edu/voh/
• Questions http//vohweb.chem.ucla.edu/voh/
• First midterm February 1 (discussion January 29)
• Second midterm February 26
• Class on Jan 18, but no class on January 13
• Literature presentations are on Mondays. First
  presentation will be on January 15.
• TAs discussion section Tuesday 2 - 3 pm (YH
  6096)
• TAs office hours Wednesday 2 - 3 pm in his
  office (1220 MSB)

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Frontiers in organometallic chemistry

• Definition of organometallic chemistry
  transformations of organic compounds using
  metals.
• Organometallic chemistry is at the interface
  between inorganic and organic chemistry.
• Inorganic subset of coordination chemistry
• Organic subset of synthetic methods
• Other interdisciplinary areas
• Bioorganometallic chemistry
• Surface organometallic chemistry
• Fullerene-metal complexes

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History first organometallic compound

• 1760 Louis Claude Cadet de Gassicourt (Paris)
  investigates inks based on cobalt salts and
  isolates cacodyl from cobalt minerals containing
  arsenic (CoAs2 and CoAsS2)
• As2O3 4 CH3COOK ? AsMe22 first
  organometallic compound
• See editorial Organometallics 2001, 20, 1488
  -1498
• Timeline
• 1751 - Benjamin Franklin Lightning is electrical
  
• 1767 Carbonated water Joseph Priestley
• 1778 - Antoine Lavoisier (and Joseph Priestley)
  discovery of oxygen leading to end of Phlogiston
  theory

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First transition metal organometallic compound

• 1827 Zeises salt is the first platinum - olefin
  complex
• See editorial Organometallics 2001, 20, 2-6
• Timeline
• 1827 Friction match John Walker
• 1827 Fountain-pen  Petrache Poenaru
• 1827 - Georg Ohm Ohm's law (Electricity)
• 1827 - Amedeo Avogadro Avogadro's law (Gas
  laws)
• 1828 - Friedrich Wöhler synthesized urea,
  destroying vitalism
• 1829 Steam locomotive George Stephenson

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History 1900 1950

• 1863 Charles Friedel and James Crafts prepare
  organochlorosilanes
• 1890 Ludwig Mond discovers Ni(CO)4
• 1893 Alfred Werner develops the modern ideas of
  coordination chemistry
• 1899 introduction of Grignard reagents
• 1912 Nobel prize Victor Grignard and Paul
  Sabatier
• 1917 Schlenk prepares Li alkyls via
  transalkylation from R2Hg
• 1930 Ziegler and Gilman simplify organolithium
  preparation, using ether cleavage and alkyl
  halide metallation, respectively

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History 1950 1960

• 1951 1952 Discovery of ferrocene, Fe(h5-C5H5)2
• Keally, Pauson, and Miller report the synthesis
• Wilkinson and Woodward report the correct
  structure
• 1973 Nobel prize Geoffrey Wilkinson and Ernst
  Otto Fischer on sandwich compounds
• 1955 Ziegler and Natta develop olefin
  polymerization at low pressure using mixed metal
  catalysts (transition metal halide / AlR3)

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Ziegler/Natta polymerization

• Giulio Natta Italian chemist, Nobel prize 1963
• Learned of Zieglers research, and applied
  findings to other a-olefins such as propylene and
  styrene.
• Resulting polypropylene was made up of two
  fractions amorphous (atactic) and crystalline
  (tactic). Polypropylene is not produced in
  radical initiated reactions.

Control of polymer tacticity
1963 Nobel prize for Karl Ziegler and Giulio
Natta on Ziegler-Natta catalysts
http//www.nobel.se/chemistry/laureates/1963/
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History 1960 1980 catalysis

• 1962 Vaskas complex
• 1964 Fischer reports the first metal carbene.

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History olefin metathesis

• 1964 Banks reports the first example of olefin
  metathesis.
• 1971 Yves Chauvin proposes mechanism.
• 1974 Schrock synthesizes first metal alkylidene
  complex.

13
2005 Nobel prize in chemistry
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C-H activation

• Oxidative addition
• Electrophilic activation
• Sigma bond metathesis

Shilov, 1972
C-H activation requires very reactive species.
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Ligands in organometallic chemistry

• Neutral 2e donors PR3 (phosphines), CO
  (carbonyl), R2CCR2 (alkenes), RCCR (alkynes,
  can also donate 4e), NCR (nitriles)
• Anionic 2e donors X- (halide), CH3- (methyl),
  CR3- (alkyl), Ph- (phenyl), H- (hydride) The
  following can also donate 4e if needed, but
  initially count them as 2e donors (unless they
  are acting as bridging ligands) OR- (alkoxide),
  SR- (thiolate), NR2- (inorganic amide), PR2-
  (phosphide)
• Anionic 4e donors C3H5- (allyl), O2- (oxide),
  S2- (sulfide), NR2- (imide), CR22-
  (alkylidene)and from the previous list OR-
  (alkoxide), SR- (thiolate), NR2- (inorganic
  amide), PR2- (phosphide)
• Anionic 6e donors Cp- (cyclopentadienyl), O2-
  (oxide)
• Z ligands do not bring e to the metal BR3, AlR3

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Nomenclature
h1-dppe / k1-dppe
- bridging ligand