ERC FUNDED PROJECTS

Many significant global challenges in catalysis for energy and sustainable chemistry have already been solved in nature. Metalloenzymes within microorganisms catalyse the transformation of carbon dioxide into simple carbon building blocks or fuels, the reduction of dinitrogen to ammonia under ambient conditions and the production and utilisation of dihydrogen. Catalytic sites for these reactions are necessarily based on metals that are abundant in the environment, including iron, nickel and molybdenum. However, attempts to generate biomimetic catalysts have largely failed to reproduce the high activity, stability and selectivity of enzymes. Proton and electron transfer and substrate binding are all finely choreographed, and we do not yet understand how this is achieved. This project develops a suite of new experimental infrared (IR) spectroscopy tools to probe and understand mechanisms of redox metalloenzymes in situ during electrochemically-controlled steady state turnover, and during electron-transfer-triggered transient studies. The ability of IR spectroscopy to report on the nature and strength of chemical bonds makes it ideally suited to follow the activation and transformation of small molecule reactants at metalloenzyme catalytic sites, binding of inhibitors, and protonation of specific sites. By extending to the far-IR, or introducing mid-IR-active probe amino acids, redox and structural changes in biological electron relay chains also become accessible. Taking as models the enzymes nitrogenase, hydrogenase, carbon monoxide dehydrogenase and formate dehydrogenase, the project sets out to establish a unified understanding of central concepts in small molecule activation in biology. It will reveal precise ways in which chemical events are coordinated inside complex multicentre metalloenzymes, propelling a new generation of bio-inspired catalysts and uncovering new chemistry of enzymes.

1 997 286 €

Start date: 2019-03-01, End date: 2024-02-29

Breakthroughs in numerical relativity in 2005 gave us unprecedented access to the strong-field regime of general relativity, making possible solutions of the full nonlinear Einstein equations for the merger of two black holes. Numerical relativity is also crucial to study fundamental physics with gravitational-wave (GW) observations: numerical solutions allow us to construct models that will be essential to extract physical information from observations in data from Advanced LIGO and Virgo, which will operate from late 2015. Complete signal models will allow us to follow up our first theoretical predictions of the nature of black-hole mergers with their first observational measurements. The goal of this project is to advance numerical-relativity methods, deepen our understanding of black-hole mergers, and map the parameter space of binary configurations with the most comprehensive and systematic set of numerical calculations performed to date, in order to produce a complete GW signal model. Central to this problem is the purely general-relativistic effect of orbital precession. The inclusion of precession in waveform models is the most challenging and urgent theoretical problem in the build-up to GW astronomy. Simulations must cover a seven-dimensional parameter space of binary configurations, but their computational cost makes a naive covering unfeasible. This project capitalizes on a breakthrough preliminary model produced by my team in 2013, with the pragmatic goal of focussing on the physics that will be measurable with GW detectors over the next five years. My team at Cardiff is uniquely placed to tackle this problem. Since 2005 I have been at the forefront of black-hole simulations and waveform modelling, and the Cardiff group is a world leader in analysis of GW detector data. This project will consolidate my team to make breakthroughs in strong-field gravity, astrophysics, fundamental physics and cosmology using GW observations.

1 998 009 €

Start date: 2015-10-01, End date: 2020-09-30

Highly excited electronic states of small atmospheric molecules play an important, but as yet little explored, role in the reactivity, and in the evolution of plasmas, including the Aurora Borealis, in the upper atmosphere of the Earth. Processes involving these highly excited states are very challenging to investigate theoretically because of the high density of states close to the ionization limits where they lie. Therefore, experimental input is essential for the identification of the reaction and decay mechanisms, and the quantum states of importance in future studies. However, experimental techniques that can be exploited to provide this input have only become available very recently. These techniques permit gas-phase molecular samples in these highly excited states to be confined in traps for sufficient lengths of time (e.g. 1 ms – 10 ms) for detailed studies to be performed in a controlled laboratory environment. They include resonance-enhanced and non-resonance-enhanced multiphoton excitation of long-lived high angular momentum Rydberg states of small molecules, and chip-based devices for efficiently decelerating, transporting and trapping these samples. With the support of this Consolidator Grant a new experimental research program will be developed in the Department of Physics and Astronomy at University College London involving laboratory based studies of (1) inelastic scattering processes, and (2) the decay mechanisms of gas-phase atmospheric molecules, including N2, O2 and NO, and their constituent atoms, in high Rydberg states. The planned experiments will be directed toward understanding the effects of static and time-dependent electric and magnetic fields, and blackbody radiation fields on slow dissociation processes that occur in highly excited states of N2, O2 and NO, investigations of collisional energy transfer processes, and studies of the role that these excited electronic states play in the evolution and reactivity of atmospheric plasmas incl

1 985 553 €

Start date: 2016-06-01, End date: 2021-05-31

The desire to “freely suspend the constituents of matter” in order to study their behaviour can be traced back over 200 years to Lichtenberg’s diaries. From radio-frequency ion traps to optical tweezing of colloidal particles, existing methods to trap matter in free space or solution rely on the use of external fields that often strongly perturb the integrity of a macromolecule in solution. Recently, I invented the ‘electrostatic fluidic trap’, a “field-free” principle that supports stable, non-destructive confinement of single macromolecules in room temperature fluids, representing a paradigm shift in a nearly century-old field. The spatio-temporal dynamics of a single electrostatically trapped molecule reveals fundamental information on its properties, e.g., size and electrical charge. The charge of a macromolecule is in turn a strong function of its 3D conformation - the molecular basis of biological function. I now aim to develop a new platform to study 3D macromolecular structure and temporal conformation by measuring the electrical charge of a single trapped molecule in real time, using both optical microscopy and electrical detection. Beyond the conformational dynamics of a single molecule, we will also examine interactions between two or more molecules, and the detection of minute structural differences between closely related molecular isoforms. We will further develop a novel approach to electrical transport measurements on single molecules aimed at generating for the first time a catalog of ‘electrical signatures’ for biomolecules in solution. The ability to experimentally link electrical charge and molecular structure will not only open up a new physical dimension in our understanding of macromolecules, but also advance the development of ultrasensitive, high-throughput molecular sensors for biomedical detection and analytics, potentially enabling an optical or electrical “single-snapshot” read-out of the proteome or transcriptome of a single cell.

2 124 965 €

Start date: 2018-06-01, End date: 2023-05-31