Wolf Prize Laureate in Chemistry 2021
Affiliation at the time of the award:
Weizmann Institute of Science, Israel
“for collaboratively established the fundamental reciprocal influences of three-dimensional molecular structure upon structures of organic crystals”.
Crystal formation is one of the most fundamental phenomena in chemistry. The structure of organic crystals is of particular importance because the crystal shape (morphology) reflects the three-dimensional structure (stereochemistry) of the molecules assembled in that crystal. In 1848 Louis Pasteur conducted his famous experiment, physically separating the two crystalline forms of a tartaric acid salt, which mirror one another. Pasteur’s experiment became the basis for modern stereochemistry, and it was followed by the study of the first Nobel Laureate in Chemistry, Jacobus H. van’t Hoff. However, neither Pasteur, van’t Hoff, nor many other famous chemists failed to understand the relationship between crystal morphology and molecular stereochemistry.
It took nearly 140 years until Professors Lahav and Leiserowitz conducted their milestone experiments in the Mid-1980s, demonstrating for the first time that the absolute configuration of molecules can be derived from their crystal morphologies. They not only solved the long-standing puzzle but also pioneered the science of organic crystals’ stereochemistry. They directly related the stereochemistry of the individual molecule to the shape of the macroscopic crystal. They founded the links between molecular structure, crystal morphology, crystal growth’ dynamics, and molecular chirality (the structural property of an object, which makes it different from its mirror image, like the human hands). Their findings laid the foundation for our current knowledge of the selective self-assembly of organic molecules. In this way, their rules powerfully complement our understanding of organic chemistry for covalent assembly and macromolecules’ self-assembly.
Furthermore, Lahav and Leiserowitz applied their theories for the design and engineering of chiral crystals, controlling the relative growth-rate of crystal faces through both acceleration and inhibition with trace amounts of specific chiral additives. They have engineered two- and three-dimensional crystals and explained their crystal growth dynamics. They have demonstrated for the first time that it was possible to design crystals that could lead to products that were not available by conventional methods. They have also explained variety of pathological crystallization, including those of cholesterol in blood vessels, and malaria pigment in Plasmodium infected red blood cells.
Since all biological systems are composed of molecules of a single chirality, the fundamental scientific question of the origin of life on Earth is closely related to the origin of chirality in nature. Lahav and Leiserowitz have addressed possible pathways to this phenomenon by showing that specific chemical reactions can display chiral amplification in forming one component from a racemic mixture (a mixture of both chiral forms in equal proportions). They demonstrated how polymerization within two-dimensional racemic crystallites could generate homochiral oligopeptides. These observations, therefore, valuably link small-molecule organic assembly in crystals to consequent homochiral biopolymers. Thus, their elegant experiments have created theoretical bases for the emergence of life’s complex chemical machinery from simpler prebiotic mixtures.