Chemists quantify the rate of historical chemical discovery

Abstract

Scientists don’t know the limits of chemical space—the collection of all possible molecules—but a new analysis concludes that chemists have discovered new compounds in that space at an exponential rate over the past 200 years (Proc. Natl. Acad. Sci. U.S.A. 2019, DOI: 10.1073/pnas.1816039116). Guillermo Restrepo of Max Planck Institute for Mathematics in the Sciences and colleagues used the Reaxys database to generate a list of more than 14 million compounds reported in scientific journals and patents between 1800 and 2015. Plotting the number of molecules reported each year revealed that new compound discoveries grew 4.4% annually. The paper “provides what is bound to be a useful historical tool,” says Ronald Brashear, director of the Donald F. and Mildred Topp Othmer Library of Chemical History at the Science History Institute. Brashear says this computational approach to history is a valuable complement to other methods used by historians. In addition to observing