Chem 652 Spring 2013
Introduction and History of Organometallic Chemistry
Prof. Donald Watson
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Assistant Professor"
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Syllabus
Chemistry 652: Organometallic Chemistry
Spring 2013, University of Delaware
Lecture: Thursday, 7-10 PM, Brown Lab (BRL) 207
Office hour: By appointment.
Please see printed syllabus for more details.
Website:
http://www.udel.edu/chem/dawatson/classes/Chem652_S13/Chem652_S13-home.html
Required Text:
Organotransition Metal Chemistry - From Bonding to Catalysis, Hartwig, J.
Recommend Texts (Optional):
The Organometallic Chemistry of the Transition Metals, 5th edition, Crabtree, R.
Transition Metals in the Synthesis if Complex Organic Molecules, 3rd Ed, Hegedus, L. S.
Organometallic Chemistry, 2nd Ed, Spessard G. O. and Miessler, G. L.
Organometallic Chemistry and Catalysis, Astruc, D.
I have requested that all three of these texts reserve in the Chemistry Library this semester.
Approximate List of Topics
Grading
Breakdown:
Midterm Exam 40%
Final Exam 40%
Problem Sets 20%
Exams:
Exams will be closed book, closed note. Exams will cover lecture
material, problem sets, assigned reading, as well as current literature
discussed in class.
Problem Sets:
3 or 4 for semester. Turn in for grade. Done check only. Must do own
work.
Please see regrade and academic dishonesty policies.
Introduction
•  Organometallic Chemistry: The study of ANY compound or
process that involves a direct metal-carbon bond.
•  Typically also includes metal hydride and metal silicon
complexes.
•  Examples:
Ti(CH3)4, Cr(CO)6, Cp2ZrCl2, BuLi, RMgBr, (PPh3)3Pd(Ph)Cl
Why Study Organometallic Chemistry?
1)  Fundamental Science: Understanding the nature of the
interesting and useful complexes.
2)  Organic Synthesis: Organometallic Complexes allow
many powerful synthetic organic transformations that can
not be accomplished without metals, including Heck,
Suzuki, asymmetric hydrogenation reactions.
3)  Bulk Chemical Synthesis and Catalysis: Huge industrial
importance to organometallic processes, including
commodity chemicals, plastics, petroleum, etc.
4)  Material Science: Chemical vapor deposition for
depositing thin-films of metals. Complex organometallics
for advanced materials, such as organic light emitting
diodes.
5)  Bioinorganic Chemistry: Some overlap, such as with Vit.
B12, hydrogenase, carbonylase, etc.
6)  Energy Science: Emerging subfield of catalysis.
Importance of OM Transformations
Acetic acid 1700 metric tons (1990)
H3C
5/2 O2
CH3
Co(II)
2CH3CO2H
H2O
Wacker process: 273 metric tons (1990)
C2H4
+
1/2 O2
PdCl42– / Cu+
CH3CHO
Terephthalic acid and ester synthesis: 3496 metric tons (1990)
CH3
CO2H
Co(II), Mn(II)
–OAc, –Br
CH3
CO2H
Importance of OM Transformations
hydroformylation: 1820 metric tons (1990)
R
+ CO
+ H2
Co2(CO)8
R
CHO
CHO
+
R
polymerization: 12,000 metric tons (1990) now 1011 lbs of polymer a
year
Ni complexes
R
Z-N catalysts, others
polymer(s)
Zeiss Salt (1825)
Pt(IV)Cl4 + Pt(II)Cl2
EtOH
heat
Cl
black solid
KCl
Cl
H2O
Cl
HH
Pt
H
H
yellow crystals
•  Danish pharmacist Zeiss.
•  First organometallic isolated in pure
form.
•  Correct formula by Zeiss, confirmed
in 1861.
•  Correct structure proposed by Dewar
in 1951.
•  X-ray in 1954.
Zeise, W. C. Ann. Phys. 1831, 97, 497–541.
"
"
See: "Seyferth, D. Organometallics 2001, 20, 2–6.
Koetzle, T. F. Inorg. Chem.
1975, 14, 2653–2657.
Cadet’s Arsenical Compound (1757)
•  French pharmacist-chemist, Louis-Claude de Gassicourt.
•  Burns on exposure to air.
•  Note: Predates discovery of O2 (1778) and carbonated water (1767).
As2O3 + 4 CH3CO2K
Me
Me
As As
Me
Me
See: "Seyferth, D. Organometallics 2001, 20, 1488–1498.
Later in the 19th Century
•  Diethyl Zinc (1848), Edward Frankland
2 Zn
+ Et
ZnI2 + Zn(C2H5)2
I
Frankland, E. Q. J. Chem. Soc. 1850, 2, 263–296.
See: Seyferth, D. Organometallics 2001, 20, 2940–2955.
•  Organochlorosilanes (1863), Charles Friedel and James Crafts
•  Ni(CO)4 (1890), Ludwig Mond
CO
50 °C
Ni + 4 CO
OC
Ni
CO
CO
Mond, L. J. Chem. Soc., Trans. 1890, 57, 749–753.
Later in the 19th Century
•  1893, Alfred Werner develops modern theory of coordination chemistry.
•  Heterogeneous alkene hydrogenation (1897), Paul Sabatier.
•  Nobel Prize 1912
•  Grignard Reagents (1899), François Auguste Victor Grignard.
•  Nobel Prize 1912
Mg + R X
R-MgX
Early 20th Century
•  Hein (1919) Chromium π-complexes
[Cr(Ph)n]0,+1 n = 2, 3, 4
CrCl3 + PhMgBr
Cr
•  Fischer-Tropsch synthesis (1925)
coal
CO + H2
heterogeneous
catalyst
hydrocarbons
synthesis gas
Fuel Synthesis for WWII Germany, Apartheid South Africa
Other Notable Structures
Me
H
Me
I
Pt
OC
OC
Me
Fe
H
CO
CO
First TM-Hydride Complex
Hieber, 1931
First TM-alkyl Complex
Pope, 1909
OC
Fe
CO
CO
First TM-Diene Complex
Reilhen, 1930
Ferrocene – Modern Organometallic Chemistry's Start
Kealy and Pauson (1951)
H
MgBr
Miller, Tebboth and Tremaine
FeCl3
Fe0 + N2
NR3
fulvalene
C10H10Fe
Cp2Fe, "ferrocene"
Kealy, T. J.; Pauson, P. L.
Nature 1951, 168, 1039–1040.
H
Fe
H
However:
•  MP = 174 °C without decomp!
•  Stable in air to 500 °C!
•  Sable in conc. Bioling HCl!
Miller, S. A.; Tebboth, J. A.;
Tremaine, J. F. J. Chem. Soc.
1952, 632–635.
Ferrocene – Modern Organometallic Chemistry's Start
Wilkinson and Woodward (1952)
Fe
Wilkinson, G.; Rosenblum, M.; Whiting, M. C.; Woodward, R.
B. JACS 1952, 74, 2125–2126.
“sandwich complex”
See: "Wilkinson, G. JOMC 1975, 100, 273–278.
•  Note: Wilkinson and E. O. Fisher, 1973 Nobel Prize for work on sandwich
complexes.
•  Historical importance: First example of a robust organometallic complex, and
demonstrated that ligands design can effect stability.
"
“Modern” Landmarks
•  1955, Ziegler and Natta develop olefin polymerization using
hetereogenous mixed metal system.
•  Nobel Prize 1963.
TiCl4 + AlEt3 +
H2C CH2
n
high mw polyethylene
•  1962, Vaska’s Complex, Reversible Binding and OA/RE.
O
Ph3P
OC
Ir
Cl
O2
O
PPh3
Ph3P
OC
Ir
Cl
PPh3
Vaska's Complex
H2
H
Ph3P
OC
Ir
Cl
H
PPh3
“Modern” Landmarks
•  1964 – Fischer reports first metal carbene.
Br
CO
OC
OC
Me
W
CO
OC
CO
OMe
OC
CO
W
CO
Me
Carbyne Complex
1973
Stablized, Fisher Carbene
1964
•  1974 – Schrock synthesize metal alkylidene complex.
•  Helps establish olefin metathesis – lead to 2005 Nobel for Schrock,
Grubbs and Chauvin.
tBu
Cp
Ta
Ta
tBu
tBu
tBu
First Alkylidene
1974
Cp
Me
tBu
Ta
Ph2P
CH2
First Methylene Complex
1975
Cl
tBu
PPh2
First Alkylidyne
1976
“Modern” Landmarks
•  1961, Heck and Beslow propose Correct Mechanism for hydrofomylation.
H
HCo(CO)4
R
CO, H2
R
O
H
Heck, R.; Breslow, D. J Am
Chem Soc 1961, 83, 4023–
4027.
•  1965, Wilkinson (and independently Bennet and Coffey) report
(PPh3)3RhCl as a homogenous catalyst for alkene hydrogenation,
becomes known as Wilkinson’s Catalyst.
Ph3P
Ph3P
Rh
Cl
PPh3
Osborn, J. A.; Jardine, F. H.;
Young, J. F.; Wilkinson, G. J.
Chem. Soc. A 1966, 1711–
1732.
“Modern” Landmarks
•  1968, Knowles Reports First Example of Catalytic Asymmetric Hydrogenation
•  Leads to Nobel Prize in 2001 to Knowles, Noyori and Sharpless.
CO2H
0.15 mol% RhCl3(P*PhMeiPr)3
H2
CO2H
Me
Knowles, W. S.; Sabacky, M. J.
Chem. Commun. (London)
1968, 0, 1445–1446.
15% ee
•  1972 Mizoroki and Heck Independently Report First Catalytic Heck Reaction
•  Leads to Nobel Prize for Heck, Suzuki, and Negishi in 2010.
I
Heck, R.; Nolley, J.
JOC, 1972, 37, 2320–
2322.
1% Pd(OAc)2, Bu3N
+
75%
“Modern” Landmarks
•  1982, Bergman Reports first example of bimolecular oxidative addition to
C-H bond of an alkane.
Me
H
Me
Me
Me
Me
Me
+
Me
Ir
Me
Me3P
H
H
Me
Ir
Me
Me3P
H
Janowicz, A. H.; Bergman
Robert G J Am Chem Soc
1982, 104, 352–354.