NMR spectroscopy of Materials

We are an interdisciplinary research group applying nuclear magnetic resonance (NMR) spectroscopy to solve problems in energy and health sciences, particularly involving catalysis. We are interested in developing solid-state NMR spectroscopy tools to enable the structure determination of catalysts, energy materials and pharmaceuticals. Solid-state NMR spectroscopy is a powerful technique to elucidate the atomic-level structure of dilute species, surfaces, interfaces or defects, and probe bonding and non-bonding interactions. Our group develops powerful sensitivity enhancement approaches to accelerate advanced solid-state NMR spectroscopy, which enables us to investigate the local environment around such sites of interest in novel materials.

Methodological advances focus on the development of high field dynamic nuclear polarization (DNP), fast magic angle spinning (MAS) and indirect detection techniques to enable multinuclear, multidimensional solid-state NMR spectroscopy. We apply these advanced solid-state NMR techniques to characterize catalytic and energy-relevant materials such as organometallic compounds, heterogeneous catalysts, nanomaterials, and porous solids such as zeolites and metal organic frameworks. While our lab will primarily focus on experimental magnetic resonance work, our scientific approach will be supported by theory and computations to investigate chemical structure. We aim to utilize this comprehensive approach to guide the rational design of efficient catalysts and materials to tackle global challenges.

We are interested in applying NMR to broadly three classes of materials:

1. Homogeneous and heterogeneous organometallic catalysts.
2. Inorganic and hybrid organic-inorganic materials such as zeolites, oxide nanomaterials, and metal organic frameworks.
3. Organic materials such as carbon-based supports, polymers and pharmaceuticals.

The developmental work that enables these applications is focused in three areas in our lab:

1. Design of dynamic nuclear polarization polarizing agents, methods and sample preparation techniques.
2. Development of indirect detection solid-state NMR strategies and pulse sequences.
3. Approaches for structure determination of materials using solid-state NMR spectroscopy, computations and other techniques.

Our lab will house state-of-the-art 400 MHz Bruker MAS DNP and 600 MHz Bruker solid-state NMR spectrometers which are expected to be installed in 2025. In addition, our group has access to an 800 MHz solid-state NMR spectrometer at UVA Chemistry and computing resources at UVA. Students in our group will gain expertise in the development and application of solid-state NMR spectroscopy of materials, and have opportunities to utilize liquid-state NMR, electron paramagnetic resonance (EPR) spectroscopy, density functional theory (DFT) and other characterization techniques.

Graduate students who are interested in joining the group should contact Amrit directly and be admitted to the UVA Chemistry graduate program.

Representative publications:

A. Venkatesh, G. Casano, R. Wei, Y. Rao, H. Lingua, H. Karoui, M. Yulikov, O. Ouari, L. Emsley. Rational Design of Dinitroxide Polarizing Agents for Dynamic Nuclear Polarization to Enhance Overall Sensitivity. Angew. Chem. Int. Ed. 2024, 63, e202317337. DOI: 10.1002/anie.202317337

A. Venkatesh, G. Casano, Y. Rao, F. De Biasi, F. A. Perras, D. J. Kubicki, D. Siri, S. Abel, H. Karoui, M. Yulikov, O. Ouari, L. Emsley. Deuterated TEKPol Biradicals and the Spin-Diffusion Barrier in MAS DNP. Angew. Chem. Int. Ed. 2023, 62, e202304844. DOI: 10.1002/anie.202304844

A. Venkatesh, D. Gioffrè, B. Atterberry, L. Rochlitz, S. Carnahan, Z. Wang, G. Menzildjian, A. Lesage, C. Coperét, A. Rossini. The Molecular and Electronic Structure of Isolated Platinum Sites Enabled by Expedient Measurement of ¹⁹⁵Pt Chemical Shift Anisotropy. J. Am. Chem. Soc. 2022, 144, 13511-13525. DOI: 10.1021/jacs.2c02300

A. Venkatesh, A. Lund, L. Rochlitz, R. Jabbour, C. P. Gordon, G. Menzildjian, J. Viger-Gravel, P. Berruyer, D. Gajan, C. Copéret, A. Lesage, A. J. Rossini. The Structure of Molecular and Surface Platinum Sites Determined by DNP-SENS and Fast MAS ¹⁹⁵Pt Solid-State NMR Spectroscopy. J. Am. Chem. Soc. 2020, 142, 18936-18945. DOI: 10.1021/jacs.0c09101

A. Venkatesh, X. Luan, I. Hung, F. A. Perras, W. Huang, A. J. Rossini. t₁-Noise Eliminated Dipolar Heteronuclear Multiple Quantum Coherence Solid-State NMR Spectroscopy. Phys. Chem. Chem. Phys. 2020, 22, 20815-20828. DOI: 10.1039/D0CP03511D

A full list of publications is available at my Google Scholar Page.