NMR crystallography of molecular organics

Hodgkinson, Paul

doi:10.1016/j.pnmrs.2020.03.001

Cited by 106 publications

(117 citation statements)

References 375 publications

(553 reference statements)

Supporting

Mentioning

112

Contrasting

Unclassified

Order By: Relevance

“…Our method is based on the statistical evaluation of similarity measures between experimental chemical shifts,

and

, and permutations of the corresponding chemical shieldings,

and

, in an investigated system of nuclei

and

(related statistical parameters are summarized in Appendix A ). Using data from the solid-state NMR measurements and from calculations of crystalline structures, this method was applied in a number of “NMR crystallography” studies, as noted by Hodgkinson in the most recent review [ 19 ]. While most of these applications concerned the { 1 H, 13 C} HETCOR spectra, this approach was also used to describe the 1 H– 1 H homonuclear correlations [ 20 ].…”

Section: Resultsmentioning

confidence: 99%

A Volumetric Analysis of the 1H NMR Chemical Shielding in Supramolecular Systems

Czernek

Brus

2021

IJMS

View full text Add to dashboard Cite

The liquid state NMR chemical shift of protons is a parameter frequently used to characterize host–guest complexes. Its theoretical counterpart, that is, the 1H NMR chemical shielding affected by the solvent (1H CS), may provide important insights into spatial arrangements of supramolecular systems, and it can also be reliably obtained for challenging cases of an aggregation of aromatic and antiaromatic molecules in solution. This computational analysis is performed for the complex of coronene and an antiaromatic model compound in acetonitrile by employing the GIAO-B3LYP-PCM approach combined with a saturated basis set. Predicted 1H CS values are used to generate volumetric data, whose properties are thoroughly investigated. The 1H CS isosurface, corresponding to a value of the proton chemical shift taken from a previous experimental study, is described. The presence of the 1H CS isosurface should be taken into account in deriving structural information about supramolecular hosts and their encapsulation of small molecules.

show abstract

“…Our method is based on the statistical evaluation of similarity measures between experimental chemical shifts,

and

, and permutations of the corresponding chemical shieldings,

and

, in an investigated system of nuclei

and

Section: Resultsmentioning

confidence: 99%

A Volumetric Analysis of the 1H NMR Chemical Shielding in Supramolecular Systems

Czernek

Brus

2021

IJMS

View full text Add to dashboard Cite

show abstract

“…NMR signals are highly sensitive to local chemical bonding structures and they can be coupled with computation results to pinpoint molecular conformations. [68][69][70][71][72]3 1 Pchemical shift serves as ad irect gauge of Coulombic interaction of phosphate-zirconium coordination of adsorbed molecules (Figure 4). [73][74][75] Compared with the signals of free molecules in solution (in black), the 31 Pc ross polarization magic angle spinning (CPMAS) signals of MOF-adsorbed drugs (in blue) appear broader and encompass multiple centers.Multiple 31 P peaks indicate the diversity of coordination conformations and the breadths of 31 Ppeaks indicate the structural variations of similar geometries.…”

Section: Conformations Of Guest Drugs At the Defectsmentioning

confidence: 99%

Defect‐Assisted Loading and Docking Conformations of Pharmaceuticals in Metal–Organic Frameworks

Kang

Cao

et al. 2021

Angewandte Chemie

View full text Add to dashboard Cite

Understanding of drug-carrier interactions is essential for the design and application of metal-organic framework (MOF)-based drug-delivery systems,a nd such drug-carrier interactions can be fundamentally different for MOFs with or without defects.Herein, we reveal that the defects in MOFs play ak ey role in the loading of many pharmaceuticals with phosphate or phosphonate groups.T he host-guest interaction is dominated by the Coulombic attraction between phosphate/ phosphonate groups and defect sites,a nd it strongly enhances the loading capacity.F or similar molecules without ap hosphate/phosphonate group or for MOFs without defects,t he loading capacity is greatly reduced. We employed solid-state NMR spectroscopyand molecular simulations to elucidate the drug-carrier interaction mechanisms.T hrough as ynergistic combination of experimental and theoretical analyses,t he docking conformations of pharmaceuticals at the defects were revealed.

show abstract

“…This covers also the problem of better locating labile hydrogen atoms, with real benefits for crystal engineering approaches aimed at developing materials with tailored functionalities based on the directional and reversible character of hydrogen bonding. Although a precision limit that could be generally guaranteed in any case is not possible to be defined, the numerous examples in the literature [ 67 ], including the systems investigated in our research group that are discussed in more details below [ 59 , 82 , 84 , 85 , 86 , 87 ], clearly illustrates the state-of-the-art reached by NMR crystallography in characterizing hydrogen-mediated noncovalent interactions. In fact, as most of these studies reveal, the power of this technique comes from the fact that potential ambiguities of the PXRD structural models, or limitations in the DFT geometry optimization, can be easily identified and corrected in practice via the analysis of the numerous ss-NMR experimental parameters that are sensitive to the interactions experienced by 1 H nuclei.…”

Section: How Accurate Can Hydrogen Atoms Position Be Constrained Bmentioning

confidence: 99%

“…A detailed description of the methodological progresses in the field of NMR crystallography and of its numerous practical applications to a variety of crystalline organic systems can be found in excellent review articles [ 58 , 67 , 68 , 69 , 70 ]. Therefore, in this mini-review we narrow the perspective and focus the presentation only on recent developments leading to enhanced ability of NMR crystallography to constrain hydrogen atom positions with increasing accuracy in the determined crystal structures.…”

Section: Introductionmentioning

confidence: 99%

Hydrogen-Mediated Noncovalent Interactions in Solids: What Can NMR Crystallography Tell About?

et al. 2020

View full text Add to dashboard Cite

Hydrogen atoms play a crucial role in the aggregation of organic (bio)molecules through diverse number of noncovalent interactions that they mediate, such as electrostatic in proton transfer systems, hydrogen bonding, and CH–π interactions, to mention only the most prominent. To identify and adequately describe such low-energy interactions, increasingly sensitive methods have been developed over time, among which quantum chemical computations have witnessed impressive advances in recent years. For reaching the present state-of-the-art, computations had to rely on a pool of relevant experimental data, needed at least for validation, if not also for other purposes. In the case of molecular crystals, the best illustration for the synergy between computations and experiment is given by the so-called NMR crystallography approach. Originally designed to increase the confidence level in crystal structure determination of organic compounds from powders, NMR crystallography is able now to offer also a wealth of information regarding the noncovalent interactions that drive molecules to pack in a given crystalline pattern or another. This is particularly true for the noncovalent interactions which depend on the exact location of labile hydrogen atoms in the system: in such cases, NMR crystallography represents a valuable characterization tool, in some cases complementing even the standard single-crystal X-ray diffraction technique. A concise introduction in the field is made in this mini-review, which is aimed at providing a comprehensive picture with respect to the current accuracy level reached by NMR crystallography in the characterization of hydrogen-mediated noncovalent interactions in organic solids. Different types of practical applications are illustrated with the example of molecular crystals studied by our research group, but references to other representative developments reported in the literature are also made. By summarizing the major concepts and methodological progresses, the present work is also intended to be a guide to the practical potential of this relatively recent analytical tool for the scientists working in areas where crystal engineering represents the main approach for rational design of novel materials.

show abstract

NMR crystallography of molecular organics

Cited by 106 publications

References 375 publications

A Volumetric Analysis of the 1H NMR Chemical Shielding in Supramolecular Systems

A Volumetric Analysis of the 1H NMR Chemical Shielding in Supramolecular Systems

Defect‐Assisted Loading and Docking Conformations of Pharmaceuticals in Metal–Organic Frameworks

Hydrogen-Mediated Noncovalent Interactions in Solids: What Can NMR Crystallography Tell About?

Contact Info

Product

Resources

About