Johannes Martin Bijvoet, (1892–1980)

J. M. Bijvoet was a Dutch chemist and crystallographer at van't Hoff Laboratory (University of Utrecht). Utrecht University (Universiteit Utrecht in Dutch) is a university in Utrecht, The Netherlands. ...

The concept of tetrahedral bound carbon in organic compounds stems back to the independent work by Jcaobus van't Hoff and Joseph Achille Le Bel, 1874. At this time, it was impossible to assign the absolute configuration by other means as the referring to the projection formula established by E. Fischer. He, Fischer, used Glyceraldehyde as prototype and assigned by chance the absolute configuration.

Bijvoet outlined the principle in 1949, which relays on the anomalous dispersion of X-ray radiation. Instead of a normally observed elastic scattering of atoms being hit by X-ray radiation, generating a scattered wave of same energy and only π-shift in phase; X-ray radiation near the absorption edge of the atom concerned creates a partial ionisation process. Some new X-ray radiation is generated from inner shells of the atoms, Kα radiation being non-directed. The X-ray radiation being already scattered interferes as such now both amplitude and phase are altered. These additional contributions of the scattering may be written as a real part Δf' and an imaginary one, Δf''. Whereas the real part is either positive or negative, the imaginary remains always positive; resulting an addition of the phase angle.

In 1951, using an X-ray tube with Zirconium target, Bijvoet and his coworkers Peerdeman and van Bommel achieved the first experimental determination of the absolute configuration of sodium rubidium tartrate. In this compound, rubidium atoms were the ones close to the absorption edge. In their later publication in Nature, entitled Determination of the absolute configuration of optically active compounds by means of X-rays, the authors conclude that

"The result is that Emil Fisher's convention, which assigned the configuration of FIG. 2 to the dextrorotatory acid appears to answer the reality."

Later it was proven that Fischer's assignment was correct.

The determination of the absolute configuration is nowadays achieved X-ray using "soft" radiation, most prominently generated with a Copper target. Despite being often the ultimate proof, other techniques are often used as faster alternative: 2D-NMR and CD-spectroscopy.

• Bijvoet, J. M. Proc. Acad. Sci. Amst. 52, 1949, 313.
• Peerdeman, A. F., van Blommel, A. J., Bijvoet, J. M. Proc. Acad. Sci. Amst. 54, 1951, 16.
• Peerdeman, A. F., van Blommel, A. J., Bijvoet, J. M. Nature 168, 1951, 271.