SSCU Seminar
Name: Dr. Tamali Nag
Affiliation: Marie Skłodowska Curie Postdoctoral Fellow at CNRS, UCCS–University of Lille, France
Title: From Interfaces to Non-Covalent Interactions: Advanced Solid-State NMR and DNP of Functional Materials
Date & Time: Tuesday, 21st July 2026 at 11.00 a.m.
Venue: A-104 Lecture Hall, First Floor, Chemical Sciences Building
Abstract:
The growing demand for sustainable technologies and the global energy crisis have intensified the search for advanced materials that can address these pressing challenges. In this context, we have developed a class of environmentally benign, non-toxic semiconductor nanostructures with tunable optoelectronic properties, making them promising candidates for next-generation energy and optoelectronic applications. In addition, the investigation of non-covalently assembled chalcogen-bonded cocrystals is also discussed in detail, which are an emerging class of functional materials with significant potential in catalysis, crystal engineering, and pharmaceutical sciences, while offering a cost-effective alternative to many conventional systems.
Realizing the full potential of these materials requires an atomic-level understanding of their local structure, interfaces, dynamics, and chemical environments, which ultimately govern their macroscopic properties and performance. Advanced solid-state nuclear magnetic resonance (NMR) spectroscopy provides a powerful platform to probe these structural features, particularly in systems that are inaccessible to conventional characterization techniques. By performing multinuclear solid-state NMR, we investigate a wide range of challenging nuclei, including 17O, 33S, 77Se, 79/81Br, and 125Te, 35Cl and many other, thereby obtaining detailed insights into their local atomic environments.
However, the characterization of low-sensitivity and high-quadrupolar nuclei remains inherently challenging owing to their low natural abundance, broad spectral line shapes arising from strong quadrupolar interactions, and intrinsically low sensitivity. To overcome these limitations, we employ state-of-the-art ultra-high-field solid-state NMR spectrometers operating at magnetic fields of up to 21.1 T (900 MHz) at the National Research Council (NRC), Ottawa, Canada, and 28.2 T (1.2 GHz) at the University of Lille, France. These ultra-high magnetic fields substantially improve both spectral resolution and sensitivity, enabling the discrimination of complex local environments that are often unresolved at conventional fields. In addition, Dynamic Nuclear Polarization (DNP)-enhanced solid-state NMR, performed at cryogenic temperatures (~30 K) at CEA Grenoble, France, provides orders-of-magnitude sensitivity enhancements, facilitating the characterization of dilute surface species, buried interfaces, and otherwise inaccessible structural motifs. Collectively, these advanced solid-state NMR methodologies deliver unprecedented atomic-scale insights into complex functional materials, establishing direct correlations between local atomic structure and macroscopic material properties.