Solid State NMR for Nonexperts: An Overview of Simple but General Practical Methods

Abstract

There are varieties of methods available for the exploration of solids using nuclear magnetic resonance (NMR) spectroscopy. Some of these methods are quite sophisticated, others require specialized equipment. This review is addressed to those for whom NMR is not the main research method. It discusses simple methods that can be applied to solids with little or no adaptation to a specific system. Despite their technical simplicity and ease of use, these methods are powerful analytical tools that provide unique insights into the structure, dynamics, and noncovalent interactions in homo- and heterogeneous systems. Particular attention is paid to the characterization of porous materials and solids containing phosphorus. 31P NMR of organometallic compounds has been used as an example of how theoretical calculations can help in deeper analysis of experimental data.

NMR Properties of the Cyanide Anion, a Quasisymmetric Two-Faced Hydrogen Bonding Acceptor

“…In this paper the isotropic value of these shielding tensors, σ iso = (σ 11 + σ 22 + σ 33 )/3, and their span, Ω = σ 33 − σ 11 , will be discussed. More detailed description can be found elsewhere [86][87][88].…”

Mesoporous Silica Particles as Drug Delivery Systems—The State of the Art in Loading Methods and the Recent Progress in Analytical Techniques for Monitoring These Processes

“…Contrary to other techniques, SS NMR can be applied to any solid physical state (both crystalline and amorphous) and materials of different complexity, from pure APIs or excipients to solid dispersions (including commercial preparations) [ 165 ]. Moreover, the development of NMR methodology and the use of new experiments, especially fast magic angle spinning (MAS) [ 170 , 171 , 172 , 173 ], dynamical nuclear polarization (DNP), and surface-enhanced NMR spectroscopy (SENS) [ 174 , 175 , 176 ], makes the SS NMR the premier method in the study of mesoporous materials, drugs confined in nanocarriers and API-MSN interactions [ 170 , 177 , 178 ].…”

Modeling of the Response of Hydrogen Bond Properties on an External Electric Field: Geometry, NMR Chemical Shift, Spin-Spin Scalar Coupling

“…In this work we have converted the calculated 15 N isotropic chemical shieldings, σ iso , to chemical shifts, δ iso , δ iso = σ ref − σ iso , where σ ref is the isotropic chemical shielding in free C≡N-H in the given approximation. More about this issue can be found elsewhere [98][99][100]. The original σ iso ( 15 N) are reported in Supplementary Materials.…”