the age of 65, his work resulted in 25 papers and 65 patents, and in 1967, he published two works describing the methods of synthesizing crown ethers (cyclic polyethers). 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. 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. It was while working on this research that Pedersen made his discovery of crown ether. Through studying the bio[2-(o-Hydroxyphenoxy)Ethyl] ether, Pedersen accidentally discovered an unknown substances described as a “goo” while purifying the compound. 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. Basing further research on this observation, Pedersen then dipped the unknown product in methanol and sodium hydroxide. Although the solution was not soluble in methanol, it became alkaline when in contact with the sodium hydroxide. Due to not being soluble in methanol, Pedersen then proceeded to treat the methanol with soluble sodium salts, to which the unknown substance became soluble, allowing him to conclude that the solubility was due to sodium ions instead of alkalinity. Since the behavior of this substance mirrored that of 2,3-benzo-1,4,7-trioxacyclononane, with twice the molecular-weight, the unknown molecule was then coined as dibenzo-18-crown-6, the first of the aromatic crown compounds discovered. Associations with other chemists Reed M. Izatt In 1968 Izatt was on a train ride home when he stopped in Chicago to meet with the physiologist George Eisenman who informed Izatt about Pedersen's paper on crown ethers published only months earlier. Izatt was looking forward to the possibilities of studying these crown ethers with his thermionic titration technique. Izatt called Pedersen and was the first scientist not at DuPont to meet with Pedersen about his discovery and Pedersen supplied him with a sample of his new crown ether