Malcolm Levitt group

Research

Malcolm H. Levitt

mhl@soton.ac.uk

We research on nuclear magnetic resonance (NMR) which is a powerful spectroscopic technique for examining the structure of matter, involving the use of a strong magnet and radio waves.

NMR allows us to examine the molecular structure of matter, determine how the molecules are arranged and how they are moving. In the form of magnetic resonance imaging (MRI), NMR allows the non-invasive determination of human anatomy and diagnosis of conditions such as cancer.

Our group researches on NMR methodology. We discover new ways to examine and understand the structure of matter, and we introduce new experiments and procedures into methods such as MRI and analytical NMR.

Our research is highly interdisciplinary, involving chemistry, biology, electromagnetism, quantum physics, cryogenic engineering and numerical computations. We have numerous international and UK collaborations, including the following groups:

  • Richard and Lynda Brown (Southampton Chemistry): synthesis
  • Richard Whitby (Southampton Chemistry): synthesis, physical chemistry and photochemistry
  • Marcel Utz (Southampton Chemistry): electromagnetics and biochemistry
  • Ilya Kuprov (Southampton Chemistry): theory and computations
  • Marina Carravetta (Southampton Chemistry): solid-state NMR
  • Joern Werner and Phil Williamson (Southampton Biochemistry): biochemistry
  • Yifeng Yang (Southampton Engineering): cryogenics
  • Hendrick Ulbricht (Southampton Physics): quantum physics
  • John Morton (UCL Physics): electron magnetic resonance
  • Tony Horsewill (Nottingham Physics): neutron scattering and cryogenic NMR
  • Kevin Brindle (Cambridge Biochemistry): in vivo NMR and MRI
  • Walter Köckenberger (Nottingham Physics): hyperpolarization
  • Jan-Henrik Ardenkjaer-Larsen (Copenhagen, Denmark): hyperpolarization
  • Toomas Rõõm (Tallinn, Estonia): infrared and THz spectroscopy
  • Ivo Heinmaa (Tallinn, Estonia): cryogenic NMR
  • Ron Lawler (Brown University, USA): photochemistry
  • Rahim Rizi (Univ Pennsylvania Medical School, USA): hyperpolarization and in vivo NMR/MRI
  • Koichi Komatsu and Yas Murata (Kyoto, Japan): synthesis
  • Marco Geppi (Pisa, Italy): chemistry

 

Click the image to access details of my textbook Spin Dynamics (2nd edition, Wiley, 2007) and links to errata and comments.

 

 

 

 

Click the image to access my software SpinDynamica for general and powerful spin dynamical simulations in the symbolic and numerical environment of Mathematica.

 

 

Research


 

 

Nuclear singlet states

Our group demonstrated that in some circumstances, it is possible to exploit long-lived nuclear singlet states that have much longer lifetimes than ordinary nuclear magnetization. In some cases we demonstrated maintenance of nuclear spin order for over half-an-hour in a room-temperature liquid. Our group is currently combining long-lived singlet states with hyperpolarization technology, which can enhance NMR signals by many orders of magnitude, but which suffers from the limited lifetime of the effect. By generating hyperpolarized singlet states we hope to maintain the hyperpolarization for a long time, which could have benefits in many forms of NMR spectroscopy and MRI.

 

Molecular Quantum Rotors

 

Molecular rotors are systems with exceptionally high degrees of internal molecular mobility. The picture shows one of the systems we are studying: molecules of dihydrogen (H2) enclosed in a modified fullerene cavity. The dihydrogen molecules are completely free to rotate, even at cryogenic temperatures, and behave as quantum rotors. The physical properties of these systems are very interesting, since the spin and spatial degrees of freedom are entangled.

 

Magic-Angle Spinning

 

MAS improves the sensitivity and resolution of NMR spectra, but averages out dipole-dipole interactions which carry molecular structural information. We are developing recoupling methods which allow this information to be recovered under high-resolution conditions. Our main approach is symmetry-based recoupling. We are also developing and applying techniques for measuring J-couplings in solids, in the presence of MAS. We are applying these MAS techniques to rhodopsin, zeolites, and molecular rotors. We are also developing equipment for MAS at cryogenic temperatures.

 

Cryogenic Magic-Angle-Spinning NMR

 

The aim of this project is to enhance the signal strength of solid-state nuclear magnetic resonance (NMR) by performing experiments on rapidly-rotating samples at cryogenic temperatures (approaching the boiling point of liquid helium).

By the end of the project, we expect to:

  • develop hardware capable of spinning solid samples at temperatures down to 20 Kelvin and rotation frequencies in excess of 15 kHz, with a stability in excess of 5 Hz;
  • develop chemical agents (“cryorelaxors”) capable of accelerating nuclear spin relaxation at cryogenic temperatures;
  • perform cryoMAS NMR on isotopically-labelled biomolecules, in order to demonstrate the expected sensitivity enhancement by a factor of 10-20.

 

Membrane Proteins: Rhodopsin

Rhodopsin is a 7-helix transmembrane protein which is found in the eyes of higher organisms. It captures photons and transduces the optical impulse into a chemical signal. In collaboration with the groups of Johan Lugtenburg and Huub de Groot in Leiden, and Wim de Grip in Nijmegen, we have used solid state NMR to study the conformational changes of this molecule upon visual excitation.

The image shows the X-ray structure of rhodopsin (from K. Palczewski, et al., Science 289, 739-745 (2000)), showing the helices of the opsin protein and the 11-cis-retynilidene ligand that captures the light (space-filling model).

 

 

 


People

Dr. Javier Alonso-Valdesueiro

Post Doc

Research interests:

• RF Coils and Circuits in NMR/MRI
• DNP Microwave Instrumentation
• Magnets, Gradients and Shim Coils Design

  

  J.Alonso-Valdesueiro@soton.ac.uk

Dr. Benno Meier

Post Doc

Research interests:

• Hyperpolarization
• Long-Lived States
• Dissolution-Dynamic Nuclear Polarization

  Publications

  B.Meier@soton.ac.uk

 

Dr. Gabriele Stevanato

Post Doc


Research interests:

• Hyperpolarized long-lived states
• Liquid state NMR methodology
• Dissolution-DNP
• Multispin systems theory
• Numerical simulations

  

  gs3g12@soton.ac.uk

Mike Jolly

PhD Student

Research interests:

• The development of cryogenic magic angle spinning NMR for biomolecular systems
• Investigating dynamic processes at cryogenic temperatures
• The application of cryogenic NMR to the characterisation of biomolecular systems

 

  

  mmj1g09@soton.ac.uk

Stuart Elliott

PhD Student

Research interests:

• Hyperpolarization
• Long-Lived States
• Microfluidics

 

  

  sje1g13@soton.ac.uk

Dr. Karel Kouril

Post Doc

Research interests:

• Solid State NMR
• Endofullerenes
• Cryogenic NMR Instrumentation

  k.kouril@soton.ac.uk

Dr. Pär Håkansson

Post Doc

Research interests:

• MD and Quantum chemistry, Long-lived Nuclear spin state
• Stochastic Liouville equation, explicit time dependent molecular degrees of freedom
• Quantum Monte Carlo for transition metal systems
• Uncertainty quantification solving stochastic PDEs
• Bayesian Statistics and Monte Carlo methods

 

  Publications

  p.hakansson@soton.ac.uk

Dr. Maria Concistrè

Post Doc

Research interests:

• Solid State NMR of bio-samples
• Solid State NMR of membrane Proteins
• Cryogenic Solid State NMR

 

  Publications

  mariac@soton.ac.uk

James Eills

 

Phd Student


James Eills Research interests:

• Long-Lived Nuclear Spin States
• Hyperpolarization
• Liquid Crystals
• Parity Non-Conservation

  eills@soton.ac.uk

Dr. Giuseppe Pileio

Senior Research FellowGP Picture

Research interests:

• Long-lived nuclear spin states
• Hyperpolarised NMR/MRI
• Nuclear Spin Relaxation
• Determination of structures in multi-labeled solids
• NMR in Liquid Crystals

  Homepage

  Publications

  g.pileio@soton.ac.uk

Publications


Resources


 

Presentations


Malcolm Levitt’s conference presentations, seminars and tutorials.

pdf files are available at the links

2014

  • iMR-CDT research conference, Dundee, Scotland, April 2014.
    • Topic: Long-lived states and spin isomers. pdf

Personal


Malcolm Levitt’s personal website is here: www.malcolmhlevitt.com

Some of Malcolm’s music may be listened to here

The latest track “Hold Me Now” is here:

 

 

 

 

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