Karl Ziegler
Encyclopedia
Karl Waldemar Ziegler was a German chemist
who won the Nobel Prize in Chemistry
in 1963, with Giulio Natta
, for work on polymer
s. The Nobel Committee recognized his "excellent work on organometallic compounds [which]...led to new polymerization reactions and ... paved the way for new and highly useful industrial processes". He is also known for his work involving free-radicals, many-membered rings, and organometallic compounds, as well as the development of Ziegler-Natta catalyst
. One of many awards Ziegler received was the Werner von Siemens Ring
in 1960 jointly with Otto Bayer
and Walter Reppe
, for expanding the scientific knowledge of and the technical development of new synthetic materials.
near Kassel
, Germany and was the second son of Karl Ziegler, a Lutheran minister, and Luise Rall Ziegler. He attended Kassel-Bettenhausen in elementary school. An introductory physics textbook first sparked Ziegler's interest in science. It drove him to perform experiments in his home and to read extensively beyond his high school curriculum. He was also introduced to many notable individuals through his father, including Emil Adolf von Behring
, recognized for the diphtheria vaccine. His extra study and experimentation help explain why he received an award for most outstanding student in his final year at high school in Kassel, Germany. He studied at the University of Marburg and was able to omit his first two semesters of study due to his extensive background knowledge. His studies were interrupted however, as during 1918 he was deployed to the . front as a soldier to serve in World War I
. He received his Ph.D. in 1920, studying under Karl von Auwers
. His dissertation was on "Studies on semibenzole and related links" which led to three publications.
In 1936 he became Professor and Director of the Chemical Institute (Chemisches Institut) at the University of Halle/Saale and was also a visiting lecturer at the University of Chicago
. From 1943 until 1969, Ziegler was the Director of the Max Planck Institute for Coal Research
(Max-Planck-Institut fur Kohlenforschung) formerly known as the Kaiser-Wilhelm Institute for Coal Research (Kaiser-Wilhelm-Institut fur Kohlenforschung) in Mülheim an der Ruhr as a successor to Franz Fischer
.
Karl Ziegler was credited for much of the post war resurrection of chemical research in Germany and helped in founding the German Chemical Society (Gesellschaft Deutscher Chemiker) in 1949. He served as president for five years. He was also the president of the German Society for Petroleum Science and Coal Chemistry (Deutsche Gesellschaft für Mineralölwissenschaft und Kohlechemie), which was from 1954 to 1957.
Ziegler and his wife were great lovers of the arts, particularly paintings. Karl and Maria would present each other with paintings for birthdays, Christmases, and anniversaries. They amassed a large collection of paintings, not necessarily of one particular period, but of paintings they enjoyed. Maria, being an avid gardener, particularly enjoyed flower paintings by Emil Nolde
, Erich Heckel
, Oskar Kokoschka
, and Karl Schmidt-Rottluff
. Karl enjoyed pictures of the places that he and his wife called home, including pictures of Halle and the Ruhr valley. Forty-two images from their shared collection were incorporated into a foundation, bequeathed to the Mülheim Ziegler Art Museum.
As a man of many discoveries, Karl Ziegler was also a man of many patents. As a result of his patent agreement with the Max Planck Institute, Ziegler was a wealthy man. With part of this wealth, he set up the Ziegler Fund with some 40 million deutsche marks to support the institute's research. Another namesake is the Karl-Ziegler-Schule, an urban high school that was founded on December 4, 1974, renaming a previously existing school. The school is located in Mülheim, Germany.
Karl Ziegler died in Mülheim
, Germany August 12, 1973.
of carbon-carbon bonds in substituted ethane
derivatives? This question was to lead Ziegler on to a study of free radicals, organometallics
, ring compounds
, and, finally, polymerization processes
.
. He was encouraged to try to synthesize similarly substituted free radicals, and successfully prepared 1,2,4,5-tetraphenylallyl in 1923 and pentaphenylcyclopentadienyl in 1925. These two compounds were much more stable than previous tri-valent carbon free radicals, such as triphenylmethyl
. His interest in the stability of tri-valent carbon free-radical compounds brought him to publish the first of many publications in which he sought to identify the steric and electronic factors responsible for the dissociation of hexa-substituted ethane derivatives.
s possessing terminal cyano groups. The initially formed ring compound was then converted to the desired macrocyclic ketone product. Ziegler’s synthetic method, which included running reactions at high dilution to favor the intramolecular cyclization over competing intermolecular reactions, resulted in yields superior to those of existing procedures (Laylin): he was able to prepare large-ringed alicyclic ketones, C14 to C33, in yields of 60-80%. An outstanding instance of this synthesis was the preparation of muscone
, the odiferous principle of animal musk by Lavoslav Ružička
. Ziegler and co-workers published the first of their series of papers on the preparation of large ring systems in 1933. For his work in this area and in free-radical chemistry he was awarded the Liebig Memorial Medal in 1935.
s. He discovered that ether scission opened a new method of preparing sodium and potassium alkyls, and found that these compounds could easily be converted to the hexa-substituted ethane derivatives. The nature of the substituent could be easily and systematically altered using this synthetic route by simply changing the identity of the ether starting material.
s are one of the most versatile and valuable tools of the synthetic organic chemist. Ziegler’s own research on lithium alkyls and olefins was to lead directly to his discovery of a new polymerization technique some 20 years later.
stilbene was added to an ethyl ether solution of phenylisopropyl potassium, an abrupt color change from red to yellow took place. He had just observed the first addition of an organoalkali metal compound across a carbon-carbon double bond. Further work showed that he could successively add more and more of the olefinic hydrocarbon butadiene to a solution of phenylisopropyl potassium and obtain a long-chain hydrocarbon with the reactive organopotassium end still intact. Oligomer
s such as these were the forerunners of the so-called “living polymers
”
, ethylene
was readily available as a byproduct from coal gas. Because of this cheap feedstock of ethylene and the relevance to the coal industry, Ziegler began experimenting with ethylene, and made it a goal to synthesize polyethylene of high molecular weight. His attempts were thwarted because a competing elimination reaction kept occurring causing an anomalous result: instead of ethylene being converted into a mixture of higher aluminum alkyls, its dimer, 1-butene
, was almost the only product. It was reasoned that a contaminant must have been present to cause this unexpected elimination reaction, and the cause was eventually determined to be traces of nickel salts. Ziegler realized the significance of this finding; if a nickel salt could have such a dramatic influence on the course of an ethylene-aluminum alkyl reaction, then perhaps another metal might delay the elimination reaction
. Ziegler and his student H. Breil found that salts of chromium
, zirconium
, and especially titanium
did not promote the R2AlH-elimination but, instead, enormously accelerated the “growth” reaction. Simply passing ethylene, at atmospheric pressure, into a catalytic amount of TiCl3 and Et2AlCl dissolved in a higher alkane led to the prompt deposition of polyethylene. Ziegler was able to obtain high molecular weight polyethylene (MW > 30,000) and, most importantly, to do so at low ethylene pressures. The Ziegler group suddenly had a polymerization procedure for ethylene superior to all existing processes.
was acting as a consultant. Natta denoted this class of catalysts as “Ziegler catalysts” and became extremely interested in their ability and potential to stereoregularly polymerize α-olefins such as propene. Ziegler, meanwhile concentrated mainly on the large-scale production of polyethylene
and copolymers of ethylene
and propylene
. Soon the scientific community was informed of his discovery. Highly crystal
line and stereoregular polymers that previously could not be prepared became synthetically feasible. For their work on the controlled polymerization of hydrocarbons through the use of these novel organometallic catalysts, Karl Ziegler and Giulio Natta shared the 1963 Nobel Prize in Chemistry.
Chemist
A chemist is a scientist trained in the study of chemistry. Chemists study the composition of matter and its properties such as density and acidity. Chemists carefully describe the properties they study in terms of quantities, with detail on the level of molecules and their component atoms...
who won the Nobel Prize in Chemistry
Nobel Prize in Chemistry
The Nobel Prize in Chemistry is awarded annually by the Royal Swedish Academy of Sciences to scientists in the various fields of chemistry. It is one of the five Nobel Prizes established by the will of Alfred Nobel in 1895, awarded for outstanding contributions in chemistry, physics, literature,...
in 1963, with Giulio Natta
Giulio Natta
Giulio Natta was an Italian chemist and Nobel laureate. He won a Nobel Prize in Chemistry in 1963 with Karl Ziegler for work on high polymers.-Early years:...
, for work on polymer
Polymer
A polymer is a large molecule composed of repeating structural units. These subunits are typically connected by covalent chemical bonds...
s. The Nobel Committee recognized his "excellent work on organometallic compounds [which]...led to new polymerization reactions and ... paved the way for new and highly useful industrial processes". He is also known for his work involving free-radicals, many-membered rings, and organometallic compounds, as well as the development of Ziegler-Natta catalyst
Ziegler-Natta catalyst
A Ziegler–Natta catalyst is a catalyst used in the synthesis of polymers of 1-alkenes . Three types of Ziegler–Natta catalysts are currently employed:* Solid and supported catalysts based on titanium compounds...
. One of many awards Ziegler received was the Werner von Siemens Ring
Werner von Siemens Ring
The Werner von Siemens Ring is considered to be among the highest ranking awards for technical sciences in Germany. It has been awarded from 1916 to 1941 and since 1952 about every three years by the foundation Stiftung Werner-von-Siemens-Ring...
in 1960 jointly with Otto Bayer
Otto Bayer
Otto Bayer was a German industrial chemist at IG Farben who was head of the research group that discovered the polyaddition for the synthesis of polyurethanes out of polyisocyanate and polyol. It may be noted that although Dr. Bayer shared the name of his venerable employer, he was not actually...
and Walter Reppe
Walter Reppe
Walter Julius Reppe was a German chemist. He is notable for his contributions to the chemistry of acetylene.-Education and career:...
, for expanding the scientific knowledge of and the technical development of new synthetic materials.
Early life and education
Karl Ziegler was born November 26, 1898 in HelsaHelsa
Helsa is a municipality and village in the district of Kassel, in Hesse, Germany. The municipality is situated in the Losse valley amongst the hills of the Kaufunger Wald, approx. 15 km east of Kassel.-Division of the municipality:...
near Kassel
Kassel
Kassel is a town located on the Fulda River in northern Hesse, Germany. It is the administrative seat of the Kassel Regierungsbezirk and the Kreis of the same name and has approximately 195,000 inhabitants.- History :...
, Germany and was the second son of Karl Ziegler, a Lutheran minister, and Luise Rall Ziegler. He attended Kassel-Bettenhausen in elementary school. An introductory physics textbook first sparked Ziegler's interest in science. It drove him to perform experiments in his home and to read extensively beyond his high school curriculum. He was also introduced to many notable individuals through his father, including Emil Adolf von Behring
Emil Adolf von Behring
Emil Adolf von Behring was a German physiologist who received the 1901 Nobel Prize in Physiology or Medicine, the first one so awarded.-Biography:...
, recognized for the diphtheria vaccine. His extra study and experimentation help explain why he received an award for most outstanding student in his final year at high school in Kassel, Germany. He studied at the University of Marburg and was able to omit his first two semesters of study due to his extensive background knowledge. His studies were interrupted however, as during 1918 he was deployed to the . front as a soldier to serve in World War I
World War I
World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...
. He received his Ph.D. in 1920, studying under Karl von Auwers
Karl von Auwers
Karl Friedrich von Auwers was a German chemist and the academic adviser of Karl Ziegler and Georg Wittig at the University of Marburg.-Life:...
. His dissertation was on "Studies on semibenzole and related links" which led to three publications.
Career
Karl Ziegler possessed an eagerness for science at an early age. He progressed through schooling quickly receiving a doctorate from the University of Marburg in 1920. Soon after, he briefly lectured at the University of Marburg and the University of Frankfurt. In 1926 he became a professor at the University of Heidelberg where he spent the next ten years researching new advances in organic chemistry. He investigated the stability of radicals on trivalent carbons leading him to study organometallic compounds and their application in his research. He also worked on the syntheses of multi-membered ring systems. In 1933 Zielger published his first major work on large ring systems, “Vielgliedrige Ringsysteme” which presented the fundamentals for the Ruggli-Ziegler dilution principle.In 1936 he became Professor and Director of the Chemical Institute (Chemisches Institut) at the University of Halle/Saale and was also a visiting lecturer at the University of Chicago
University of Chicago
The University of Chicago is a private research university in Chicago, Illinois, USA. It was founded by the American Baptist Education Society with a donation from oil magnate and philanthropist John D. Rockefeller and incorporated in 1890...
. From 1943 until 1969, Ziegler was the Director of the Max Planck Institute for Coal Research
Max Planck Institute for Coal Research
The Max Planck Institute für Kohlenforschung is a chemical research institute located in Mülheim an der Ruhr, Germany. The institute is part of the Max-Planck-Gesellschaft, a network of scientific research institutes mainly located in Germany...
(Max-Planck-Institut fur Kohlenforschung) formerly known as the Kaiser-Wilhelm Institute for Coal Research (Kaiser-Wilhelm-Institut fur Kohlenforschung) in Mülheim an der Ruhr as a successor to Franz Fischer
Franz Fischer
Franz Fischer may refer to:-* Franz Fischer , cellist and Hofkapellmeister in München* Franz Joseph Emil Fischer , chemist, famous for Fischer-Tropsch process-See also:...
.
Karl Ziegler was credited for much of the post war resurrection of chemical research in Germany and helped in founding the German Chemical Society (Gesellschaft Deutscher Chemiker) in 1949. He served as president for five years. He was also the president of the German Society for Petroleum Science and Coal Chemistry (Deutsche Gesellschaft für Mineralölwissenschaft und Kohlechemie), which was from 1954 to 1957.
Personal life
In 1922, Ziegler married Maria Kurtz. They had two children, Erhart and Marianna. His daughter, Dr. Marianna Ziegler Witte was a doctor of medicine and married a chief physical of a children's hospital (at that time) in the Ruhr. His son, Dr. Erhart Ziegler, became a physicist and patent attorney. In addition to his children, Karl Ziegler has five grandchildren by his daughter, and five by his son. At least one of his grandchildren, Cordula Witte, attended his Nobel Prize reception as there is a picture of the two of them happily dancing. Ziegler enjoyed traveling around the world with his family, especially on cruises. He even charted special cruises and airplanes for eclipse viewing. It was during a 1972 eclipse-viewing cruise with his grandson that Karl Ziegler became ill. He died a year later.Ziegler and his wife were great lovers of the arts, particularly paintings. Karl and Maria would present each other with paintings for birthdays, Christmases, and anniversaries. They amassed a large collection of paintings, not necessarily of one particular period, but of paintings they enjoyed. Maria, being an avid gardener, particularly enjoyed flower paintings by Emil Nolde
Emil Nolde
Emil Nolde was a German painter and printmaker. He was one of the first Expressionists, a member of Die Brücke, and is considered to be one of the great oil painting and watercolour painters of the 20th century. He is known for his vigorous brushwork and expressive choice of colors...
, Erich Heckel
Erich Heckel
Erich Heckel was a German painter and printmaker, and a founding member of the Die Brücke group which existed 1905-1913.-Biography:Heckel was born in Döbeln . His parents were born in Saxony...
, Oskar Kokoschka
Oskar Kokoschka
Oskar Kokoschka was an Austrian artist, poet and playwright best known for his intense expressionistic portraits and landscapes.-Biography:...
, and Karl Schmidt-Rottluff
Karl Schmidt-Rottluff
Karl Schmidt-Rottluff was a German expressionist painter and printmaker, and a member of Die Brücke.-Life and work:...
. Karl enjoyed pictures of the places that he and his wife called home, including pictures of Halle and the Ruhr valley. Forty-two images from their shared collection were incorporated into a foundation, bequeathed to the Mülheim Ziegler Art Museum.
As a man of many discoveries, Karl Ziegler was also a man of many patents. As a result of his patent agreement with the Max Planck Institute, Ziegler was a wealthy man. With part of this wealth, he set up the Ziegler Fund with some 40 million deutsche marks to support the institute's research. Another namesake is the Karl-Ziegler-Schule, an urban high school that was founded on December 4, 1974, renaming a previously existing school. The school is located in Mülheim, Germany.
Karl Ziegler died in Mülheim
Mülheim
Mülheim an der Ruhr, also called "City on the River", is a city in North Rhine-Westphalia in Germany. It is located in the Ruhr Area between Duisburg, Essen, Oberhausen and Ratingen...
, Germany August 12, 1973.
Scientific Advancements
Throughout his life, Ziegler was a zealous advocate for the necessary indivisibility of all kinds of research. Because of this, his scientific achievements range from the fundamental to the most practical, and his research spans a wide range of topics within the field of chemistry. As a young professor, Ziegler posed the question: what factors contribute to the dissociationDissociation (chemistry)
Dissociation in chemistry and biochemistry is a general process in which ionic compounds separate or split into smaller particles, ions, or radicals, usually in a reversible manner...
of carbon-carbon bonds in substituted ethane
Ethane
Ethane is a chemical compound with chemical formula C2H6. It is the only two-carbon alkane that is an aliphatic hydrocarbon. At standard temperature and pressure, ethane is a colorless, odorless gas....
derivatives? This question was to lead Ziegler on to a study of free radicals, organometallics
Organometallic chemistry
Organometallic chemistry is the study of chemical compounds containing bonds between carbon and a metal. Since many compounds without such bonds are chemically similar, an alternative may be compounds containing metal-element bonds of a largely covalent character...
, ring compounds
Carbon ring
Carbon rings are rings of carbon atoms. Rings of five and six carbons are by far the most common, as they allow bond angles close to the ideal angle of 109.5°. Rings of three and four are possible, but with bond angles of 60° and 90°, they have a larger ring strain and are unstable...
, and, finally, polymerization processes
Polymerization
In polymer chemistry, polymerization is a process of reacting monomer molecules together in a chemical reaction to form three-dimensional networks or polymer chains...
.
Free Radical Compounds
While still a doctoral student at University of Marburg, Ziegler published his first major article which showed how halochromic (R3C+Z-) salts could be made from carbinols. Previous work had left the impression that halochromic salts or free radicals (R3C•) required R to be aromaticAromaticity
In organic chemistry, Aromaticity is a chemical property in which a conjugated ring of unsaturated bonds, lone pairs, or empty orbitals exhibit a stabilization stronger than would be expected by the stabilization of conjugation alone. The earliest use of the term was in an article by August...
. He was encouraged to try to synthesize similarly substituted free radicals, and successfully prepared 1,2,4,5-tetraphenylallyl in 1923 and pentaphenylcyclopentadienyl in 1925. These two compounds were much more stable than previous tri-valent carbon free radicals, such as triphenylmethyl
Triphenylmethyl radical
The triphenylmethyl radical is a persistent radical and the first-ever radical described in organic chemistry. It can be prepared by homolysis of triphenylmethyl chloride 1 by a metal like silver or zinc in benzene or diethyl ether. The radical 2 forms a chemical equilibrium with the quinoid type...
. His interest in the stability of tri-valent carbon free-radical compounds brought him to publish the first of many publications in which he sought to identify the steric and electronic factors responsible for the dissociation of hexa-substituted ethane derivatives.
Many-Membered Ring Compounds
Ziegler’s work with many-membered ring compounds also utilized the reactive nature of alkali metal compounds. He used strong bases such as the lithium and sodium salts of amines, to accomplish the cyclization of long-chain hydrocarbonHydrocarbon
In organic chemistry, a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. Hydrocarbons from which one hydrogen atom has been removed are functional groups, called hydrocarbyls....
s possessing terminal cyano groups. The initially formed ring compound was then converted to the desired macrocyclic ketone product. Ziegler’s synthetic method, which included running reactions at high dilution to favor the intramolecular cyclization over competing intermolecular reactions, resulted in yields superior to those of existing procedures (Laylin): he was able to prepare large-ringed alicyclic ketones, C14 to C33, in yields of 60-80%. An outstanding instance of this synthesis was the preparation of muscone
Muscone
Muscone is an organic compound that is the primary contributor to the odor of musk.The chemical structure of muscone was first elucidated by Lavoslav Ružička. It consists of a 15-membered ring ketone with one methyl substituent in the 3-position. It is an oily liquid that is found naturally as...
, the odiferous principle of animal musk by Lavoslav Ružička
Lavoslav Ružicka
Lavoslav Ružička FRS born as Lavoslav Ružička was a Croatian scientist and winner of the 1939 Nobel Prize in Chemistry who worked most of his life in Switzerland...
. Ziegler and co-workers published the first of their series of papers on the preparation of large ring systems in 1933. For his work in this area and in free-radical chemistry he was awarded the Liebig Memorial Medal in 1935.
Organometallic Compounds
Ziegler’s work with free radicals led him to the organo compounds of the alkali metalAlkali metal
The alkali metals are a series of chemical elements in the periodic table. In the modern IUPAC nomenclature, the alkali metals comprise the group 1 elements, along with hydrogen. The alkali metals are lithium , sodium , potassium , rubidium , caesium , and francium...
s. He discovered that ether scission opened a new method of preparing sodium and potassium alkyls, and found that these compounds could easily be converted to the hexa-substituted ethane derivatives. The nature of the substituent could be easily and systematically altered using this synthetic route by simply changing the identity of the ether starting material.
Lithium Alkyls
Later, in 1930, He directly synthesized lithium alkyls and aryls from metallic lithium and halogenated hydrocarbons. 4Li+2RX – 2RLi This convenient synthesis spurred numerous studies of RLi reagents by others, and now organolithium reagentOrganolithium reagent
An organolithium reagent is an organometallic compound with a direct bond between a carbon and a lithium atom. As the electropositive nature of lithium puts most of the charge density of the bond on the carbon atom, effectively creating a carbanion, organolithium compounds are extremely powerful...
s are one of the most versatile and valuable tools of the synthetic organic chemist. Ziegler’s own research on lithium alkyls and olefins was to lead directly to his discovery of a new polymerization technique some 20 years later.
Living Polymerization
In 1927, he found that when the olefinAlkene
In organic chemistry, an alkene, olefin, or olefine is an unsaturated chemical compound containing at least one carbon-to-carbon double bond...
stilbene was added to an ethyl ether solution of phenylisopropyl potassium, an abrupt color change from red to yellow took place. He had just observed the first addition of an organoalkali metal compound across a carbon-carbon double bond. Further work showed that he could successively add more and more of the olefinic hydrocarbon butadiene to a solution of phenylisopropyl potassium and obtain a long-chain hydrocarbon with the reactive organopotassium end still intact. Oligomer
Oligomer
In chemistry, an oligomer is a molecule that consists of a few monomer units , in contrast to a polymer that, at least in principle, consists of an unlimited number of monomers. Dimers, trimers, and tetramers are oligomers. Many oils are oligomeric, such as liquid paraffin...
s such as these were the forerunners of the so-called “living polymers
Living polymerization
In polymer chemistry, living polymerization is a form of addition polymerization where the ability of a growing polymer chain to terminate has been removed. This can be accomplished in a variety of ways. Chain termination and chain transfer reactions are absent and the rate of chain initiation is...
”
Polyethylene
Since Ziegler was working at the Max Planck Institute for Coal ResearchMax Planck Institute for Coal Research
The Max Planck Institute für Kohlenforschung is a chemical research institute located in Mülheim an der Ruhr, Germany. The institute is part of the Max-Planck-Gesellschaft, a network of scientific research institutes mainly located in Germany...
, ethylene
Ethylene
Ethylene is a gaseous organic compound with the formula . It is the simplest alkene . Because it contains a carbon-carbon double bond, ethylene is classified as an unsaturated hydrocarbon. Ethylene is widely used in industry and is also a plant hormone...
was readily available as a byproduct from coal gas. Because of this cheap feedstock of ethylene and the relevance to the coal industry, Ziegler began experimenting with ethylene, and made it a goal to synthesize polyethylene of high molecular weight. His attempts were thwarted because a competing elimination reaction kept occurring causing an anomalous result: instead of ethylene being converted into a mixture of higher aluminum alkyls, its dimer, 1-butene
1-Butene
1-Butene is an organic chemical compound, linear alpha-olefin , and one of the isomers of butene. The formula is .-Stability:1-Butene is stable in itself but polymerizes exothermically. It is highly flammable and readily forms explosive mixtures with air...
, was almost the only product. It was reasoned that a contaminant must have been present to cause this unexpected elimination reaction, and the cause was eventually determined to be traces of nickel salts. Ziegler realized the significance of this finding; if a nickel salt could have such a dramatic influence on the course of an ethylene-aluminum alkyl reaction, then perhaps another metal might delay the elimination reaction
Elimination reaction
An elimination reaction is a type of organic reaction in which two substituents are removed from a molecule in either a one or two-step mechanism...
. Ziegler and his student H. Breil found that salts of chromium
Chromium
Chromium is a chemical element which has the symbol Cr and atomic number 24. It is the first element in Group 6. It is a steely-gray, lustrous, hard metal that takes a high polish and has a high melting point. It is also odorless, tasteless, and malleable...
, zirconium
Zirconium
Zirconium is a chemical element with the symbol Zr and atomic number 40. The name of zirconium is taken from the mineral zircon. Its atomic mass is 91.224. It is a lustrous, grey-white, strong transition metal that resembles titanium...
, and especially titanium
Titanium
Titanium is a chemical element with the symbol Ti and atomic number 22. It has a low density and is a strong, lustrous, corrosion-resistant transition metal with a silver color....
did not promote the R2AlH-elimination but, instead, enormously accelerated the “growth” reaction. Simply passing ethylene, at atmospheric pressure, into a catalytic amount of TiCl3 and Et2AlCl dissolved in a higher alkane led to the prompt deposition of polyethylene. Ziegler was able to obtain high molecular weight polyethylene (MW > 30,000) and, most importantly, to do so at low ethylene pressures. The Ziegler group suddenly had a polymerization procedure for ethylene superior to all existing processes.
Ziegler-Natta Catalyst
In 1952, Ziegler disclosed his catalyst to the Montecatini Company in Italy, for which Giulio NattaGiulio Natta
Giulio Natta was an Italian chemist and Nobel laureate. He won a Nobel Prize in Chemistry in 1963 with Karl Ziegler for work on high polymers.-Early years:...
was acting as a consultant. Natta denoted this class of catalysts as “Ziegler catalysts” and became extremely interested in their ability and potential to stereoregularly polymerize α-olefins such as propene. Ziegler, meanwhile concentrated mainly on the large-scale production of polyethylene
Polyethylene
Polyethylene or polythene is the most widely used plastic, with an annual production of approximately 80 million metric tons...
and copolymers of ethylene
Ethylene
Ethylene is a gaseous organic compound with the formula . It is the simplest alkene . Because it contains a carbon-carbon double bond, ethylene is classified as an unsaturated hydrocarbon. Ethylene is widely used in industry and is also a plant hormone...
and propylene
Propylene
Propene, also known as propylene or methylethylene, is an unsaturated organic compound having the chemical formula C3H6. It has one double bond, and is the second simplest member of the alkene class of hydrocarbons, and it is also second in natural abundance.-Properties:At room temperature and...
. Soon the scientific community was informed of his discovery. Highly crystal
Crystal
A crystal or crystalline solid is a solid material whose constituent atoms, molecules, or ions are arranged in an orderly repeating pattern extending in all three spatial dimensions. The scientific study of crystals and crystal formation is known as crystallography...
line and stereoregular polymers that previously could not be prepared became synthetically feasible. For their work on the controlled polymerization of hydrocarbons through the use of these novel organometallic catalysts, Karl Ziegler and Giulio Natta shared the 1963 Nobel Prize in Chemistry.
Awards
Karl Ziegler received many awards and honors. The following highlights many of the most significant awards.- Liebig-Denkmünze medalLiebig MedalThe Liebig-Denkmünze is an award originally given annually by the Verein Deutscher Chemiker beginning in 1903. The medal is named after Justus von Liebig.- Recipients :* 1903 Adolf von Baeyer, Munich* 1904 Rudolf Knietsch, Ludwigshafen...
(1935); This medal was awarded by the present day German Chemical Society and is given to a German chemist for their outstanding accomplishments and creativity. Ziegler received the award because of his work in the synthesis of multi-membered ring systems and stable tri-valent carbon radicals. - Carl Duisberg Plakette (1953); This award is given for outstanding service to the promotion of chemistry from the German Chemical Society.
- Lavoisier MedalLavoisier MedalA Lavoisier Medal is an award made by any of a number of bodies, for achievements in chemical related disciplines. The award is named for Antoine Lavoisier, considered by some to be a father of modern chemistry....
(1955); This award is given by the French Chemical Society to scientists in various disciplines of chemistry. - Carl Engler Medal (1958); This award is given by the German Society of Petroleum Science and Coal Chemicals, of which he was the president in earlier years.
- Werner von Siemens RingWerner von Siemens RingThe Werner von Siemens Ring is considered to be among the highest ranking awards for technical sciences in Germany. It has been awarded from 1916 to 1941 and since 1952 about every three years by the foundation Stiftung Werner-von-Siemens-Ring...
(1960); This ring is awarded by the Werner von Siemens Foundation and is considered the highest German award for individuals who by their performance and skills opened up new technological paths. - Nobel Prize in ChemistryNobel Prize in ChemistryThe Nobel Prize in Chemistry is awarded annually by the Royal Swedish Academy of Sciences to scientists in the various fields of chemistry. It is one of the five Nobel Prizes established by the will of Alfred Nobel in 1895, awarded for outstanding contributions in chemistry, physics, literature,...
(1963); "[His] excellent work on organometallic compounds has unexpectedly led to new polymerization reactions and thus paved the way for new and highly useful industrial processes." - The Swinburne Medal of the Plastics Institute, London (1964); This award recognizes an individual who has made a significant advancement to the science, engineering or technology of plastics.
- Grand Federal Cross of Merit (Order of Merit of the Federal Republic of Germany)(1969); Ziegler was given this award for his work in the area of Science and Technology.
- Foreign Member of the Royal SocietyRoyal SocietyThe Royal Society of London for Improving Natural Knowledge, known simply as the Royal Society, is a learned society for science, and is possibly the oldest such society in existence. Founded in November 1660, it was granted a Royal Charter by King Charles II as the "Royal Society of London"...
(1971)