9Be nuclear magnetic resonance spectroscopy trends in discrete complexes: an update

Be-9 solution NMR spectroscopy is a useful tool for the characterisation of beryllium complexes. An updated comprehensive table of the Be-9 NMR chemical shifts of beryllium complexes in solution is presented. The recent additions span a greater range of chemical shifts than those previously reported, and more overlap is observed between the chemical shift regions of fourcoordinate complexes and those with lower coordination numbers. Four-coordinate beryllium species have smaller omega(1/2) values than the two- and three-coordinate species due to their higher order symmetry. In contrast to previous studies, no clear relationship is observed between chemical shift and the size and number of chelate rings.