thumb|[[Crown ether coordinating a potassium ion]]

Charles John Pedersen (, Yasui Yoshio, October 3, 1904 – October 26, 1989) was an American organic chemist best known for discovering crown ethers and describing methods of synthesizing them during his entire 42-year career as a chemist for DuPont at DuPont Experimental Station in Wilmington, Delaware, and at DuPont's Jackson Laboratory in Deepwater, New Jersey. Often associated with Reed McNeil Izatt, Pedersen also shared the Nobel Prize in Chemistry in 1987 with Donald J. Cram and Jean-Marie Lehn. He is one of three Nobel Prize laureates born in Korea, along with Peace Prize laureate Kim Dae-jung and Literature laureate Han Kang.

Pedersen made many other discoveries in chemistry, such as discovering and developing metal deactivators. His early investigations also led to the development of a dramatically improved process for manufacturing tetraethyl lead, an important gasoline additive. He also contributed to the development of neoprene.

Early life and education

Born on October 3, 1904, in Busan, Korea, Charles J. Pedersen was the youngest of three children. His father, Brede Pedersen, was a Norwegian marine engineer who immigrated to Korea in order to join the Korean customs service after leaving home due to family issues. Later, he worked as a mechanical engineer at the Unsan County mines in present-day North Korea. His Japanese mother, Takino Yasui, immigrated from Japan to Korea with her family and established a successful line of work by trading soybeans and silkworms located close to the Unsan County mines, where the couple ultimately met.

Despite living in what is now North Korea, because Pedersen lived in the vicinity of the American-owned Unsan County mines, which spanned approximately 500 square miles in area, he grew up speaking primarily English.

After successfully completing his education at St. Joseph College, While at DuPont, Pedersen was able to begin research at the Jackson Laboratory under William S. Calcott and finished his career with DuPont at the Experimental Station in Wilmington, Delaware. Pedersen had a particular interest in industry as he started his focus on his chemical career, which influenced the direction of problems he set out to solve as a chemist. As Pedersen began working on problems as a new chemist, he was free to work on whatever problems fascinated him and he quickly became interested in oxidative degradation and stabilization of substrate. The donut-shaped molecules were the first in a series of extraordinary compounds that form stable structures with alkali metal ions. In 1987, he shared the Nobel Prize in Chemistry for his work in this area with Donald Cram and Jean-Marie Lehn, whom expanded upon his original discoveries. In the whole process of the Nobel Prize winning, the Dupont Company fully supported Pedersen by providing him a full-time public relations man, and a part-time secretary. DuPont Company also utilized their own corporate aircraft to accompany Pedersen and his family, as he could not travel on commercial aircraft.

Discovery of the crown ethers

At around 1960, Pedersen went back to research in the field of Coordination Chemistry, focusing on the synthesis of multidentate ligands. It was recommended by his colleague Herman Schroeder to work on the coordination chemistry of vanadium before working on the polymerization and oxidative catalytic activity of vanadium. Using ultraviolet–visible spectroscopy to study its reactions with phenol groups, after treating the samples with alkali, although the absorption curve initially showed no changes, it was observed to have shifted to higher absorption readings if one or more of the hydroxy groups were unpaired.

Donald J. Cram

Cram shared the 1987 Nobel Prize in Chemistry with Pedersen but expanding on Pedersen's monumental discovery in macrocyclic chemistry of crown ethers.

Jean-Marie Lehn

Lehn was the other scientist who shared the Nobel Prize in Chemistry with Pedersen and was fundamental in starting the field of Supramolecular chemistry. Lehn's work specifically identified in his recognition for the Nobel Prize was in his work on cryptands.

Personal life

Pedersen was married to Susan J. Ault in 1947 and the couple then moved to Salem, New Jersey, where they resided until Ault died on February 8, 1983, at 72 years old. Pedersen was diagnosed with myeloma in 1983, and though he was becoming increasingly frail, he traveled to Stockholm to accept the Nobel Prize in late 1987.

Legacy

Following Pedersen's breakthrough in realizing his accidental product and structure of dibenzo-18-crown-6, huge advancements have been made in the fields of macrocyclic and supramolecular chemistry. Pedersen devoted the rest of his research career to studying these molecules and started one of the largest growths recently seen in a specific field of chemistry. This growth in Pedersen's field of work following his momentous discovery for macrocyclic compounds can be seen in the work of the 2016 Nobel Prize winner in Chemistry for molecular motors where Pedersen's work allowed for the insight in how to create the molecular specific structures. The molecular machines were recognized as the focus of the 2016 Nobel Prize Winners, which were produced by connecting molecules to various molecular rings.