Materials science NMR

Shovik Ray (Indian Institute of Science, India)

LinkedIn: @Shovik Ray; X: @ray_shovik

Abstract: Solid-state nuclear magnetic resonance (SSNMR) spectroscopy is an indispensable tool in pharmaceutical research that provides detailed structural and dynamic insights. This non-invasive technique is particularly critical for identification and quantification of polymorphs forms and tracking of local dynamics. Thus, SSNMR plays a key role at various stages of drug development from preformulation to manufacturing.
In this presentation, I will show the applications of SSNMR in characterization of co-amorphous systems, developed to enhance the solubility and dissolution rates of active pharmaceutical ingredients (APIs). In particular, the molecular interactions leading the co-amorphization of Dasatinib, a tyrosine kinase inhibitor used in chronic myeloid leukaemia therapy, with various co-amorphous systems will be discussed in detail. I will show the use of 1H, 13C and 1H-1H double quantum – single quantum correlation experiments to confirm presence or absence of inter- and intra-molecular hydrogen bonding, which is a key factor in determining formation of co-formers.
I will also discuss recent results on Venetocloax, which is a medication used to treat adults with chronic lymphocytic leukemia (CLL), small lymphocytic lymphoma (SLL) or acute myeloid leukemia (AML). Our studies highlight the capabilities of SSNMR in combination with other characterization techniques to gain pivotal information and optimize pharmaceutical formulations.

Isha Isha (Indian Institute of Science, India)

Abstract: Solid-state lithium-ion batteries (SSLBs) with lithium metal anodes present significant advantages over conventional liquid electrolyte-based lithium-ion batteries (LIBs), including higher energy densities and improved safety. The flammability of liquid electrolytes and the formation of dendrites at the electrodes are critical safety concerns in traditional LIBs. Furthermore, the energy density of conventional LIBs (200–300 Wh kg⁻¹) is insufficient for long-distance applications in battery-powered devices, and their operational temperature range is limited to -20°C to 60°C.
Implementing solid electrolytes (SEs) offers a promising solution to these challenges. Solid polymer electrolytes (SPEs) exhibit superior mechanical properties and enhanced safety features. However, the primary limitation of SPEs is their low ionic conductivity, typically around 10-4 Scm-1 under ambient conditions, which remains a significant obstacle to their widespread adoption. Understanding the mechanism of conductivity is a crucial step. Our Research mainly focuses on understanding the conductivity mechanism of the polymer electrolytes. Ionic Conductivity depends on the structure and the dynamics of the polymer backbone, and the Solid-State NMR is the only technique that can probe both the local structure and the dynamics. The microscopic properties of the polymers, such as the local structures, phases, and dynamics significantly influence macroscopic conductivity. Understanding the structure-property relationships is crucial to design SPE(s). SS NMR spectroscopy allows non–invasive characterization with site-specific local structural and dynamical details of materials regardless of their crystallinity. The NMR interactions are susceptible to the local structures and dynamics that have been used to gain insight into ion–dynamics mechanism in SPE(s).

Konstantin Khivantsev – @Khivantsev

We show both experimentally and theoretically that CO can be activated (protonated) by Bronsted acid sites to form the super-electrophilic HCO+ cation in H-zeolites such as mordenite. This mode of activation of carbon monoxide is novel for solid materials and has not been observed before. This reactivity stems from the confining environment of zeolitic micropores. HCO+ is a catalytically active super-electrophile showing catalytic reactivity in C-H and C-O bond activation.

Madhusudan Chaudhary – @thehonestspin

Aliovalent substitution of the B component in ABX3 metal halides has often been proposed to modify the band gap and thus the photovoltaic properties, but details about the resulting structure have remained largely unknown. Here, we examine these effects in Bi-substituted CsSnBr3. Powder X-ray diffraction (XRD) and solid-state 119Sn, 133Cs and 209Bi nuclear magnetic resonance (NMR) spectroscopy were carried out to infer how Bi substitution changes the structure of these compounds. The cubic perovskite structure is preserved upon Bi-substitution, but with disorder in the B site occurring at the atomic level. Bi atoms are randomly distributed as they substitute for Sn atoms with no evidence of Bi segregation. The absorption edge in the optical spectra shifts from 1.8 to 1.2 eV upon Bi-substitution, maintaining a direct band gap according to electronic structure calculations. It is shown that Bi-substitution improves resistance to degradation by inhibiting the oxidation of Sn.

Robert Smith – @RobertSmith2652

Excited to share my latest work in the @SchurkoFSU group (in collaboration with Geoffrey Strouse's group at FSU and the @NationalMagLab) on #plasmonic semiconductor nanocrystals! #GlobalnmrOC2024 pic.twitter.com/mT4Asvkd4z

— Robert Smith (@RobertSmith2652) July 17, 2024

We demonstrate the use of solid-state NMR to probe the band structure of cadmium stannate nanocrystals through the use of Knight shifts, with a focus on methods that can be employed to confirm their manifestation. We also explore the relationship between synthetic precursors and free carrier densities.

Wenda Hu – @WendaHu1

Why does water inhibit alcohol dehydration rates more significantly on TiO2(001) than on TiO2(101)? 🧐Check out how in situ solid-state NMR deciphers this.#GlobalnmrOC2024 pic.twitter.com/AXyBKrOP4d

— Wenda Hu (@WendaHu1) July 17, 2024

We used in situ 13𝐶-1𝐻 CP and 1𝐻 NMR to identify dehydration intermediates on TiO₂ facets. A water-isopropoxide complex on TiO₂(001) and a water-isopropanol complex on TiO₂(101) explain different dehydration rates, crucial for understanding biomass conversion mechanisms.

Mikalai Artsiusheuski – @martsiush

Curious about how MAS NMR can be used to study methane conversion to methanol over copper-comntaining zeolites? Watch this introductory video highlighting our methods at #GlobalnmrOC2024. pic.twitter.com/ZSb1F4I5eL

— Mikalai Artsiusheuski (@Martsiush) July 17, 2024

Employing in situ solid-state NMR spectroscopy and label tracing, we elucidated the pathways of methane transformations over copper-containing zeolites. Reaction of methane with copper(II)-oxo sites leads to partial oxidation products, namely methanol, methoxy species and dimethyl ether. These products can undergo coupling over acid sites leading to C2+ hydrocarbons.

Yufei Wu – @YufeiWu811

Generation of formate on the surface of supported ionic liquid phases (SILPs) is related to the catalytic selectivity of hydrogenation reactions. We use solid-state NMR to study molecular interactions between formate and different SILPs. The findings indicate electrostatic interactions which explain the improved immobilization of formate on the surface.

Thomas Swift – @Swifthom

In recent years Pulsed Field Gradient NMR techniques to get Diffusion decays of materials have been successfully adopted in the polymer chemistry community as a sizing technique. It has many advantages over the previous gold standard in the field (size exclusion chromatography) although it has its own drawbacks and difficulties. Here we will focus on applications of NMR for Polymer material characterisation and the limitations thereof.

Michele Pierigé – @MichelePierige

This research compares the effects of natural and petroleum-based resins on Styrene-Butadiene Rubber (SBR) dynamics, using various techniques to understand the correlation between mechanical properties and molecular dynamics in elastomer compounds, with resin content varying from 0 to 45 parts per hundred rubber.