The long-term goal of our research program is to produce novel and impactful chemical insight into the structure and properties of chemical compounds and materials by furthering our understanding of the connection between these properties and various solid-state nuclear magnetic resonance (SSNMR) observables. More specifically, the information gained through the measurement and computation of chemical shifts (CS), quadrupolar couplings, and J couplings affords direct insight into chemical bonding, molecular and electronic structure, and the crystal structure itself.
A few areas of current interest are outlined briefly below. Please also refer to my ‘publications’ page for additional topics of interest.
1. Solid-State NMR Studies of Halogen Bonds and other Sigma-Hole Interactions
(RX…YZ) is a non-covalent
interaction between an electron donor (Y) and the electrophilic
polar region of
a halogen X. It is
responsible for many
novel effects in the structures and properties of diverse
supramolecules and biological molecules. We have published a
series of articles
describing our studies of the halogen bond with multinuclear
Historically, NMR has played a key role in the understanding of
bonding. We are now carrying out the research required to
understand the area
of halogen bonding and other sigma-hole interactions, such as
tetrel bonding, via
NMR. Our experimental data are interpreted using DFT approaches
and revealed a
unified NMR description of halogen bonds and hydrogen bonds.
Y. Xu, J.
Viger-Gravel, I. Korobkov, and D. L. Bryce
Mechanochemical Production of Halogen-Bonded Solids Featuring P=O...I-C Motifs and Characterization via X-ray Diffraction, Solid-State Multinuclear Magnetic Resonance, and Density Functional Theory
J. Phys. Chem. C, 119, 27104-27117 (2015).
S. A. Southern and D.
NMR Investigations of Non-Covalent Carbon Tetrel Bonds. Computational Assesent and Initial Experimental Observation
J. Phys. Chem. A, 119, 11891-11899 (2015). PDF.
J. Viger-Gravel, S.
Leclerc, I. Korobkov, and D. L. Bryce
Direct Investigation of Halogen Bonds by Solid-State Multinuclear Magnetic Resonance Spectroscopy and Molecular Orbital Analysis
J. Am. Chem. Soc., 136, 6929-6942 (2014). PDF.
2. Novel Effects and Applications in the Solid-State NMR Spectroscopy of Quadrupolar Nuclei
interpretation of NMR spectra of
quadrupolar nuclei (spin > 1/2), which comprise 70 % of all
on second-order perturbation theory. We discovered in 127I
and 185/187Re NMR
spectra higher-order quadrupolar effects which affect the
interpretation of the
spectra. We also demonstrated experimentally that J coupling can be observed between magnetically
quadrupolar nuclei. This
has provided a
new and unambiguous probe of crystal structure and symmetry.
This discovery has
also provided a novel window into the electronic structure and
compounds featuring quadrupolar spin pairs.
We are currently applying these methods to study
frameworks as well as the nature of metal-metal bonding in
F. A. Perras and D. L.
Boron-Boron J Coupling Constants are Unique Probes of Electronic Structure: A Solid-State NMR and Molecular Orbital Study
Chem. Sci., 5, 2428-2437 (2014).
F. A. Perras and D. L.
Symmetry-Amplified J Splittings for Quadrupolar Spin Pairs: A Solid-State NMR Probe of Homoatomic Covalent Bonds
J. Am. Chem. Soc., 135, 12596-12599 (2013)
Definitive Solid-State 185/187Re NMR Spectral Evidence for and Analysis of the Origin of High-Order Quadrupole-Induced Effects for I = 5/2
Phys. Chem. Chem. Phys., 13, 12413-12420 (2011). PDF.
3. NMR Crystallography and Polymorphism
NMR crystallography employs NMR data to refine or solve crystal structures. This hot area of research has been focussed on the interpretation of 1H and 13C chemical shifts. Our contributions have recognized that the majority of the elements in materials are quadrupolar, and that special experimental and analytical methods are required to use their NMR spectra to their full potential. We have developed a sophisticated experimental/computational protocol whereby structural models of solids are refined jointly against experimental quadrupolar couplings and a DFT-optimized energy term. The models are then further cross-validated against experimental chemical shifts. Related work on the structures of pharmaceuticals, polymorphs, and solvates has generated interest from the pharmaceutical industry. We are currently exploring novel methods to identify and detect polymorphs via in-situ NMR.
C. P. Romao, F. A. Perras, U.
Werner-Zwanziger, J. A. Lussier, K. J. Miller, C. M. Calahoo, J.
W. Zwanziger, M. Bieringer, B. A. Marinkovic, D. L. Bryce, and
M. A. White
Zero Thermal Expansion in ZrMgMo3O12: NMR Crystallography Reveals Origins of Thermoelastic Properties
Chem. Mater. 27, 2633-2646 (2015)
K. M. N. Burgess, F. A. Perras, A. Lebrun, E. Messner-Henning, I. Korobkov, and D. L. Bryce
Sodium-23 Solid-State Nuclear Magnetic Resonance of Commercial Sodium Naproxen and its Solvates
J. Pharm. Sci., 101, 2930-2940 (2012).
Multinuclear Magnetic Resonance Crystallographic Structure Refinement and Cross-Validation Using Experimental and Computed Electric Field Gradients: Application to Na2Al2B2O7
J. Phys. Chem. C, 116, 19472-19482 (2012).