Charles J. Pedersen's legacy to chemistry

Abstract

The serendipitous discovery in 1961 of dibenzo-18-crown-6 by Charles J. Pedersen marked the beginning of research on cyclic polyether macrocyclic compounds. These compounds have a remarkably selective affinity for certain metal ions and provide a framework for studying molecular recognition processes. Pedersen's work excited much interest in the scientific community and fueled important advances in macrocyclic and supramolecular chemistry. Born in Korea of a Japanese mother and a Norwegian engineer father, he was educated in Japan and later graduated from the University of Dayton (BS, chemical engineering) and Massachusetts Institute of Technology (MS, chemistry). He worked at du Pont for 42 years as a research chemist. His research talent at du Pont earned him an appointment as a Research Associate allowing him to pursue research as he chose. This freedom served him well making it possible for him to devote all his efforts following his discovery of dibenzo-18-crown-6 until his retirement to synthesis of cyclic polyethers and evaluation of their metal ion complexation properties. His influence on macrocyclic and supramolecular chemistry has been pervasive. He was co-recipient of the 1987 Nobel Prize in chemistry for development and use of molecules with structure-specific interactions of high selectivity. The year 2017 marks the fiftieth anniversary of the publication of his first paper describing his synthesis of over 50 crown ethers.

Azo group(s) in selected macrocyclic compounds

“…The year 2017 appears to be a very special for supramolecular chemistry. 50 years ago Charles Pedersen [ 1 ] published papers describing the syntheses and completely untypical and unknown until that time intriguing complexing properties of macrocyclic polyethers, i.e. crown ethers [ 2 , 3 ].…”

Crown Ethers Enable Room-Temperature Synthesis of CsPbBr3 Quantum Dots for Light-Emitting Diodes

“…20 This overcomes previous solubility limitations, and renders precursor solutions with concentrations practical for device fabrication. Crown ethers are cyclic molecules comprising of a ring (or multiple rings) of ether groups that show a remarkable selectivity to bind certain alkali metal ions via hydrogen bonding, 21,22 whereby the selectivity is mostly determined by the size of the ring structure. We have rationally chosen the DB21C7 as its cavity is of sufficient size (3.4-4.3 Å) to coordinate the Cs + cations (3.3 Å) 23 via weak van der Waals interactions with the lone electron pairs of the oxygen atoms within the ring structure (Figure 1b), forming a host-guest complex, thus facilitating its solubilization in DMF.…”

Cycling a Tether into Multiple Rings: Pt‐Bridged Macrocycles for Differentiated Guest Recognition, Pseudorotaxane Transformations, and Guest Capture and Release

“…Since Pedersen's seminal work on crown ethers, [1, 2] the synthesis of macrocycles has been central to supramolecular chemistry [3] . The library of known ring molecules is vast, encompassing diverse compositions, geometries and sizes [4–9] .…”