Publications de Amrit Venkatesh

Solid Effect Dynamic Nuclear Polarization Enhancement of >500 at 9.4 T

David Lyndon Emsley, Yu Rao, Amrit Venkatesh

Efficient polarizing agents for dynamic nuclear polarization (DNP) enhanced magic angle spinning (MAS) NMR spectroscopy is of high current interest due the potential to significantly boost NMR sensitivity. While most efforts have centered on cross-effect ( ...

American Chemical Society (ACS)2024

Rational Design of Dinitroxide Polarizing Agents for Dynamic Nuclear Polarization to Enhance Overall NMR Sensitivity

David Lyndon Emsley, Yu Rao, Amrit Venkatesh

We evaluate the overall sensitivity gains provided by a series of eighteen nitroxide biradicals for dynamic nuclear polarization (DNP) solid-state NMR at 9.4 T and 100 K, including eight new biradicals. We find that in the best performing group the factors ...

Wiley-VCH Verlag GmbH2024

Efficient DNP at high fields and fast MAS with antenna-sensitized dinitroxides

David Lyndon Emsley, Amrit Venkatesh

Dynamic Nuclear Polarization (DNP) can significantly enhance the sensitivity of solid-state NMR. In DNP, microwave irradiation induces polarization transfer from unpaired electron spins to 1H nuclear spins via hyperfine couplings and spin-diffusion. The st ...

2024

An Efficient and Stable Polarizing Agent for In-Cell Magic-Angle Spinning Dynamic Nuclear Polarization NMR Spectroscopy

Marinella Mazzanti, David Lyndon Emsley, Pierrick Berruyer, Andrea Bertarello, Amrit Venkatesh

Nuclear Magnetic Resonance (NMR) spectroscopy would be a method of choice to follow biochemical events in cells because it can analyze molecules in complex environments. However, the intrinsically low sensitivity of NMR makes in-cell measurements challengi ...

2024

Deuterated TEKPol Biradicals and the Spin-Diffusion Barrier in MAS DNP

Dominik Józef Kubicki, David Lyndon Emsley, Yu Rao, Amrit Venkatesh, Federico De Biasi

The sensitivity of NMR spectroscopy is considerably enhanced by dynamic nuclear polarization (DNP). In DNP polarization is transferred from unpaired electrons of a polarizing agent to nearby proton spins. In solids, this transfer is followed by the transpo ...

Wiley-VCH Verlag GmbH2023

Dynamic nuclear polarisation of 1H in Gd-doped In(OH)3

David Lyndon Emsley, Michael Allan Hope, Amrit Venkatesh, Yuxuan Zhang

Dynamic nuclear polarisation (DNP) of solids doped with high-spin metal ions, such as Gd3+, is a useful strategy to enhance the nuclear magnetic resonance (NMR) sensitivity for these samples. Spin diffusion can relay polarisation throughout a sample, which ...

Academic Press Inc - Elsevier Science2023

Colloidal-ALD Grown Hybrid Shells Nucleate via a Ligand–Precursor Complex

David Lyndon Emsley, Raffaella Buonsanti, Anna Loiudice, Snaedis Björgvinsdóttir, Kevin Rossi, Michael Allan Hope, Ona Segura Lecina, Amrit Venkatesh

Colloidal atomic layer deposition (c-ALD) enables the growth of hybrid organic/inorganic oxide shells with tunable thickness at the nanometer scale around ligand-functionalized inorganic nanoparticles (NPs). This recently developed method has demonstrated ...

2022

Atomic-Level Structure of Zinc-Modified Cementitious Calcium Silicate Hydrate

Paul Bowen, Karen Scrivener, Manuel Cordova, David Lyndon Emsley, Anna Morales Melgares, Pinelopi Moutzouri, Ziga Casar, Amrit Venkatesh

It has recently been demonstrated that the addition of zinc can enhance the mechanical strength of tricalcium silicates (C3S) upon hydration, but the structure of the main hydration product of cement, calcium silicate hydrate (C-S-H), in zinc modified form ...

AMER CHEMICAL SOC2022

Design Principles for the Development of Gd(III) Polarizing Agents for Magic Angle Spinning Dynamic Nuclear Polarization

Anne-Sophie Chauvin, Marinella Mazzanti, David Lyndon Emsley, Gabriele Stevanato, Yu Rao, Amrit Venkatesh

Nuclear magnetic resonance suffers from an intrinsically low sensitivity, which can be overcome by dynamic nuclear polarization (DNP). Gd(III) complexes are attractive exogenous polarizing agents for magic angle spinning (MAS) DNP due to their high chemica ...

2022

H-1 Hyperpolarization of Solutions by Overhauser Dynamic Nuclear Polarization with C-13-H-1 Polarization Transfer

David Lyndon Emsley, Yu Rao, Pinelopi Moutzouri, Amrit Venkatesh

Dynamic nuclear polarization (DNP) is a method that can significantly increase the sensitivity of nuclear magnetic resonance. The only effective DNP mechanism for in situ hyperpolarization in solution is Overhauser DNP, which is inefficient for H-1 at high ...

2022