Recent Advances in 11B Solid-State Nuclear Magnetic Resonance Spectroscopy of Crystalline Solids

We review the progress made in B-11 solid-state nuclear magnetic resonance (SSNMR) spectroscopy of crystalline materials over the past 20 years, with a focus on the applications of B-11 NMR observables in providing electronic and structural information. A brief description of some of the common SSNMR methods for measuring B-11 chemical shift (CS) tensor parameters, electric field gradient (EFG) tensor parameters, and indirect spin-spin (J) coupling constants is first provided. Recent B-11 SSNMR studies on crystalline boron systems, such as diboron compounds, boronic esters and acids, borates, and boron-containing Lewis acid / base adducts, are then summarized, and the corresponding experimentally obtained B-11 NMR parameters are presented. In general, data from studies that only report isotropic CSs are not tabulated. Our survey highlights the ability of B-11 SSNMR spectroscopy to provide an abundance of diverse chemical information, ranging from the coordination environment of the boron, to ligand identity, bond strengths, bond orders and bond angles, and the potential of this technique to characterize inorganic and organic crystalline solids. Owing to the sensitivity of B-11 SSNMR spectroscopy to chemical structures and the suitability of the B-11 nuclide for high-resolution techniques such as MQMAS and DOR, we anticipate that B-11 SSNMR spectroscopy will continue to evolve as an indispensable tool for solid-state characterization of boron-containing systems and for the advancement of various fields, such as NMR crystallography, the synthesis of novel boron reagents, and the development of boron-based hydrogen storage materials.