Remembering Van’t Hoff

To celebrate C&EN’s 90th anniversary, one Editor’s Page each month examines materials from C&EN Archives. Featured articles are freely downloadable for one month.

The tetrahedral geometry of, and the possibility of chirality at, tetravalent carbon is an extraordinarily useful concept, enabling us to think about molecules as three-dimensional objects even when we can’t see them.

In 1999, I wrote about the intellectual climate that enabled the 22-year-old Dutch chemist Jacobus Henricus van’t Hoff to propose carbon’s tetrahedral coordination. In an 1874 publication, not having yet received a Ph.D., he offered the theory to explain the existence of optical and other isomers.

The chemistry elite then ridiculed van’t Hoff. In “Tetrahedral Carbon Redux” (C&EN, Sept. 6, 1999, page 28), I recall how Hermann Kolbe, then 59 and a more established chemist, attacked van’t Hoff’s idea as “phantasmagorical puffery,” “fantastic foolishness,” and “shallow speculations.” The theory endures and has opened many fertile areas of inquiry.

Some of those areas were on display last month at a symposium at Utrecht University (UU), where van’t Hoff was studying when he formulated the theory. The Division of the History of Chemistry of the American Chemical Society had awarded UU a Citation for Chemical Breakthrough Award, on the basis of van’t Hoff’s tetrahedral carbon. Representing the division, Jeffrey I. Seeman explained that “the term breakthrough refers to advances that have been revolutionary in concept, broad in scope, and long-term in impact.”

Tetrahedral carbon was the basis of much of the work discussed at the symposium. For example, Anja Palmans, of Eindhoven University of Technology, lectured about chirality from the molecular to the supramolecular scale. And Jan H. van Maarseveen, of the University of Amsterdam, discussed epimerization-free C-terminal peptide activation. “This is an extremely technical title, but it has all to do with van’t Hoff’s magnificent insight of the stereochemical features of tetrahedral carbon.” Ben L. Feringa, of the University of Groningen, took that insight all the way to designing molecular systems based on molecular assembly and recognition, including rotary molecular motors.

Others emphasized van’t Hoff’s contributions to physical chemistry and catalysis, for which he won the Nobel Prize in Chemistry in 1901. Albert Philipse, of UU, talked about the thermodynamics of magnetic colloids. He said he wanted to remind the audience that van’t Hoff’s work on osmotic pressure “had an even wider impact in chemistry, physiology, and medicine” than his work on organic chemistry. Similarly, Bert M. Weckhuysen, also of UU, emphasized the influence of van’t Hoff’s work in catalysis and his place in the pantheon of early-20th-century physical chemists, alongside Svante Arrhenius (Nobel Prize, 1903) and Wilhelm Ostwald (Nobel Prize, 1909).

The symposium was a tribute to all of van’t Hoff’s chemistry, said E. W. (Bert) Meijer, of Eindhoven. It was, he added, “a celebration of the great achievements of Dutch chemistry in fields like supramolecular chemistry, stereochemistry, and catalysis from today and the past.”