William L. Mock and Cucurbituril: The Resurrection of the Behrend Paper of 1905

Abstract

In 1905, Robert Behrend reported the preparation of a substance that remained a dry powder despite absorbing water and that had the ability to absorb dyes from solution. Over seven decades later, William L. Mock repeated the Behrend synthesis and discovered cucurbituril, a remarkably symmetric molecule with a central cavity welcoming diverse guests. Mock et al. ploughed a lonely furrow in the 1980s, establishing the versatility of cucurbituril in the field of supramolecular chemistry, including a demonstration of the Huisgen click reaction in a molecular cavity.

Figure 1

Two views of cucurbituril-6 (CB6) in crystals as reported by Freeman and Mock, drawn from the coordinate set for the entry BEBDOB10 in the CCDC database. (left) View down the 6-fold axis. (right) Space filling view, tilted to illustrate the three entrapped water molecules that lie along the 6-fold axis.

Figure 2

Growth of papers having cucurbituril in the title or abstract or author keywords and citations over the period 1981–2022.

Figure 3

Garfield historiograph based on the top 20 most cited papers (Table 1) in the collection of 1595 papers that cite six of Mock’s works published during 1981–1989 (Data as seen in WoS on 22nd September 2022). Histcite was used to draw this historiograph.