Crystallography By NMR

Abstract

For most chemists, the term crystallography is interchangeable with X-ray diffraction. But really crystallography is just the study of the forms and structures of crystals, and there are plenty of crystalline materials for which diffraction fails to reveal a structure. In recent years, advances in solid-state nuclear magnetic resonance techniques have allowed NMR to emerge as an important addition to crystallographers’ toolboxes. In some cases, researchers have used NMR to independently reproduce structures determined by X-ray diffraction. “There is deep symmetry between X-ray diffraction and NMR,” which makes the two methods complementary, says Manish A. Mehta, a professor of chemistry at Oberlin College. X-ray diffraction yields electron densities that allow scientists to then infer a molecule’s nuclear coordinates. “In solid-state NMR, it works the other way around,” Mehta says. “What you have are the nuclei that tell you something about what’s going on with the electrons around them.” But the