Recent Advances in Solid-State NMR of Alkaline Earth Elements

Recent developments in the solid-state NMR of Mg-25, Ca-43, Ba-135,Ba-137, and Sr-87 are discussed in a context of contemporary applications to inorganic, organometallic, and biological materials. While each alkaline earth nucleus presents its own unique combination of NMR challenges, together they are characterized by low intrinsic sensitivity due to their small magnetic moments and low natural abundance. Solid-state NMR advances of the last decade, particularly the increased availability of very high magnetic field beyond 17 T, the development and implementation of signal enhancement techniques for quadrupolar nuclei, progress in methods for obtaining wideline and ultra-wideline NMR spectra of solids, together with the widespread use of computational techniques, have all contributed immensely to the accelerated growth of solid-state NMR of alkaline earth nuclei and extension of the method into biology and material science. The specifics and the experimental challenges of each nucleus in solid-state NMR applications are discussed.