New Horizons in Chemical and Photochemical Dynamics
Lead Research Organisation:
University of Bristol
Department Name: Chemistry
Abstract
Chemical change, whether caused by collisions between reactive atoms, radicals and molecules, or by absorption of light (photochemistry), is of fundamental importance in all branches of Chemistry. For example, synthesis of complicated organic molecules, such as those naturally occurring in plant and animal life, or needed to construct functional modern materials, requires an in-depth understanding of reaction mechanisms to design synthetic pathways. Ideas from physical chemistry based on thermodynamics and reaction rate theory underpin our ability to predict directions of chemical change and how quickly such change will occur. The fields of chemical reaction and photodissociation have sought to place such theories on a quantitative foundation built on deep understanding of the quantum mechanics of breakage and formation of chemical bonds. Potential energy surfaces (PESs) (based on the Born-Oppenheimer separation of the fast motion of light electrons from the slower motion of heavier atomic nuclei) are an essential concept because they provide a map of the energy landscape(s) over which chemical change occurs. Minima and barriers on the PESs correspond, respectively, to stable conformations of the atoms and short-lived transition states. Photodissociation involves dynamics on PESs lying higher in energy than the lowest, ground state, with the extra energy needed to reach these excited states provided by absorption of light. A powerful driver for advances in understanding of the dynamics of photochemical and reactive processes has been a close interaction between experimental and theoretical studies - arguably, the field has done much to stimulate the development of theoretical methods to calculate PE landscapes and describe the molecular dynamics on these surfaces. Such methods (subject to simplifying approximations) are now finding widespread use in molecular modelling of, for example, drug design, enzyme catalysis, and many other fields. The historical development of experimental and theoretical methods has relied on complementary studies of systems with only a small number of atoms (e.g. photodissociation of diatomic and triatomic molecules; reaction of atoms with diatomic molecules) so that accurate PESs can be computed and precise, quantum-mechanical (QM) scattering calculations carried out. Such experiments were mostly conducted in the gas phase, in the low-temperature and rarefied environment of a molecular beam, so that complicating factors of solvation, or interaction between molecules can be ignored. Considerable success with such systems has, for example, revealed the importance of exotic QM effects in chemistry such as tunnelling through reaction barriers, scattering resonances, non-adiabatic coupling between PESs, and interference between different pathways to the same products. For a photochemical or reactive system with 3 atoms, only 3 coordinates are required to describe all the possible arrangements of the atoms and the associated PEs can thus be computed for representative configurations spanning the entire PE landscape. We now seek a multi-pronged approach to extend such studies to more complicated systems, with the intention of learning about PE landscapes for larger molecules (for N atoms, 3N-6 coordinates are needed to describe the associated PE hypersurface), the effects of jumps between PE surfaces, and to examine how the energy landscapes and chemical dynamics are changed in the presence of solvent. In so doing, we will bring the fields of reaction and photodissociation dynamics closer to the types of chemical reactions used in synthesis by organic, inorganic and biological chemists. Our strategy involves development of new experiments and theoretical methods. The substantial challenges necessitate a consortium-based approach, in which complementary expertise in two Universities is brought together to address selected problems from which we can learn much about chemical change.
Organisations
Publications
Harris SJ
(2013)
Comparing molecular photofragmentation dynamics in the gas and liquid phases.
in Physical chemistry chemical physics : PCCP
Gilchrist AJ
(2013)
Predissociation dynamics of the C 3?g Rydberg state of molecular oxygen.
in The Journal of chemical physics
Brouard M
(2013)
Origin of collision-induced molecular orientation.
in Physical review letters
Abou-Chahine F
(2013)
Photoisomerization and photoinduced reactions in liquid CCl4 and CHCl3.
in The journal of physical chemistry. A
Lehman J
(2013)
Electronic Quenching of OH A 2 S + Induced by Collisions with Kr Atoms
in The Journal of Physical Chemistry A
Burgos Paci MA
(2013)
Products of the quenching of NO A 2S+ (v = 0) by N2O and CO2.
in Physical chemistry chemical physics : PCCP
Few J
(2014)
Rate constants for collisional quenching of NO (A(2)S(+), v = 0) by He, Ne, Ar, Kr, and Xe, and infrared emission accompanying rare gas and impurity quenching.
in Physical chemistry chemical physics : PCCP
Shan X
(2014)
Quantum dynamics of the abstraction reaction of H with cyclopropane.
in The journal of physical chemistry. A
Gardiner SH
(2014)
Fragmentation dynamics of the ethyl bromide and ethyl iodide cations: a velocity-map imaging study.
in Physical chemistry chemical physics : PCCP
Tkác O
(2014)
State-to-state resolved differential cross sections for rotationally inelastic scattering of ND3 with He.
in Physical chemistry chemical physics : PCCP
Deb N
(2014)
Laser induced rovibrational cooling of the linear polyatomic ion C2H2(+).
in The Journal of chemical physics
Halford E
(2014)
Modifications to a commercially available linear mass spectrometer for mass-resolved microscopy with the pixel imaging mass spectrometry (PImMS) camera.
in Rapid communications in mass spectrometry : RCM
Orr-Ewing AJ
(2014)
Perspective: Bimolecular chemical reaction dynamics in liquids.
in The Journal of chemical physics
Slater C
(2014)
Covariance imaging experiments using a pixel-imaging mass-spectrometry camera
in Physical Review A
Bull JN
(2014)
An introduction to velocity-map imaging mass spectrometry (VMImMS).
in European journal of mass spectrometry (Chichester, England)
Grubb MP
(2014)
KOALA: a program for the processing and decomposition of transient spectra.
in The Review of scientific instruments
Harris S
(2014)
Transient electronic and vibrational absorption studies of the photo-Claisen and photo-Fries rearrangements
in Chem. Sci.
Vallance C
(2014)
Fast sensors for time-of-flight imaging applications.
in Physical chemistry chemical physics : PCCP
Preston TJ
(2014)
Direct and indirect hydrogen abstraction in Cl + alkene reactions.
in The journal of physical chemistry. A
Winter B
(2014)
A fast microchannel plate-scintillator detector for velocity map imaging and imaging mass spectrometry.
in The Review of scientific instruments
Karsili TN
(2014)
Symmetry matters: photodissociation dynamics of symmetrically versus asymmetrically substituted phenols.
in Physical chemistry chemical physics : PCCP
Chadwick H
(2014)
Inelastic Scattering of NO by Kr: Rotational Polarization over a Rainbow.
in The journal of physical chemistry letters
Brouard M
(2014)
Fully quantum state-resolved inelastic scattering of NO(X) + Kr: differential cross sections and product rotational alignment.
in The Journal of chemical physics
Tkác O
(2014)
Collision dynamics of symmetric top molecules: a comparison of the rotationally inelastic scattering of CD3 and ND3 with He.
in The Journal of chemical physics
Chadwick H
(2014)
The collisional depolarization of OH(A (2)S(+)) and NO(A (2)S(+)) with Kr.
in The Journal of chemical physics
Murdock D
(2014)
Transient UV pump-IR probe investigation of heterocyclic ring-opening dynamics in the solution phase: the role played by ns* states in the photoinduced reactions of thiophenone and furanone.
in Physical chemistry chemical physics : PCCP
Chadwick H
(2014)
Collisional depolarisation in electronically excited radicals
in International Reviews in Physical Chemistry
Bull JN
(2014)
Absolute electron total ionization cross-sections: molecular analogues of DNA and RNA nucleobase and sugar constituents.
in Physical chemistry chemical physics : PCCP
Tkác O
(2014)
Differential and integral cross sections for the rotationally inelastic scattering of methyl radicals with H2 and D2.
in The Journal of chemical physics
Lam J
(2014)
Collisional trap losses of cold magnetically trapped Br atoms
in Physical Review A
Dunning GT
(2014)
Dynamics of photodissociation of XeF2 in organic solvents.
in Physical chemistry chemical physics : PCCP
Dulitz K
(2014)
Getting a Grip on the Transverse Motion in a Zeeman Decelerator
Dulitz K
(2014)
Getting a grip on the transverse motion in a Zeeman decelerator.
in The Journal of chemical physics
Kirkbride JM
(2014)
Pump and probe spectroscopy with continuous wave quantum cascade lasers.
in The Journal of chemical physics
Kirkbride J
(2014)
Polarization spectroscopy of a velocity-selected molecular sample.
in Optics letters
Roberts GM
(2014)
On the participation of photoinduced N-H bond fission in aqueous adenine at 266 and 220 nm: a combined ultrafast transient electronic and vibrational absorption spectroscopy study.
in The journal of physical chemistry. A
Sashikesh G
(2014)
Surface ionisation of molecular H 2 and atomic H Rydberg states at doped silicon surfaces
in Molecular Physics
Wenge AM
(2015)
Tuning photochemistry: substituent effects on ps* state mediated bond fission in thioanisoles.
in Physical chemistry chemical physics : PCCP
Nichols B
(2015)
Steric effects and quantum interference in the inelastic scattering of NO(X) + Ar.
in Chemical science
Aoiz FJ
(2015)
A new perspective: imaging the stereochemistry of molecular collisions.
in Physical chemistry chemical physics : PCCP
Harris SJ
(2015)
A Multipronged Comparative Study of the Ultraviolet Photochemistry of 2-, 3-, and 4-Chlorophenol in the Gas Phase.
in The journal of physical chemistry. A
Oliver TA
(2015)
Exploring Autoionization and Photoinduced Proton-Coupled Electron Transfer Pathways of Phenol in Aqueous Solution.
in The journal of physical chemistry letters
Tkác O
(2015)
Rotationally inelastic scattering of methyl radicals with Ar and N2.
in The Journal of chemical physics
Dulitz K
(2015)
Zeeman deceleration of electron-impact-excited metastable helium atoms
in New Journal of Physics
Dulitz K
(2015)
Model for the overall phase-space acceptance in a Zeeman decelerator
in Physical Review A
Steer E
(2015)
Accurate determination of the relative concentrations of ammonia isotopologues in a cold, electrostatically guided molecular beam
in Molecular Physics
Tkác O
(2015)
Rotationally inelastic scattering of ND 3 with H 2 as a probe of the intermolecular potential energy surface
in Molecular Physics
Amini K
(2015)
Three-dimensional imaging of carbonyl sulfide and ethyl iodide photodissociation using the pixel imaging mass spectrometry camera.
in The Review of scientific instruments
Description | This EPSRC Programme Grant involving 10 research groups from the Universities of Bristol and Oxford, is making significant advances in the fundamental study of mechanisms of chemical and photochemical reactions. The use of new technology to study such chemical processes is also leading to innovations in broader areas such as analytical science. Full details of the project are given at the website http://dynamics.chem.ox.ac.uk/ and a few key outcomes to date are summarized here. (1) Advances in mass spectrometry using novel imaging detectors that can provide both spatial and velocity information. (2) Breakthroughs in the study of chemical and photochemical processes occuring in solution in liquids using femtosecond laser based transient absoprtion methods and new theoretical methods for accurate simulation of reactions in liquids. (3) Use of velocity map imaging (and related) methods to observe collisional scattering and photodissociation mechanisms with quantum-state resolution, and to explore non-adiabatic dynamics at conical intersections between electronic states. (4) Advances in fundamental theory of chemical reactions, and of the theoretical treatment of bulk liquids. (5) Develpment and application of new methods to study collisions at ultra-low temperatures. The consortium has published more than 150 papers in international journals over the course of the grant. A representative selection of these papers is given here. |
Exploitation Route | Advances in spatial and velocity map imaging led to the award of a Programme grant to the Bristol and Oxford groups to develop further these techniques and their applications (EP/L005913/1). Collaborations with SMEs Photek Ltd and SAI Ltd, as well as the PImMS consortium involving the Rutherford Appleton Laboratory and University of Oxford are advancing technical developments and applications of imaging techniques, including new methods for imaging mass spectrometry. Computational developments, for example in accurate simulation of reactions in solution, are being incorporated into major software packages for simulation of biomolecule dynamics such as CHARMM. |
Sectors | Chemicals,Creative Economy,Education,Energy,Environment,Healthcare,Pharmaceuticals and Medical Biotechnology,Other |
URL | http://dynamics.chem.ox.ac.uk/ |
Description | Developments in imaging mass spectrometry and in imaging methods are transferring to mass spectrometry manufacturers (e.g. Scientific Analysis Instruments Ltd)and manufacturers of scientific instrumentation for imaging (e.g. Photek Ltd, Photonis). The development of the Danceroom Spectroscopy project is having a substantial cultural and educational impact: see http://danceroom-spec.com/ for a list of activities. |
First Year Of Impact | 2009 |
Sector | Creative Economy,Education,Manufacturing, including Industrial Biotechology |
Impact Types | Cultural,Economic |
Description | EPSRC Programme Grant |
Amount | £4,663,077 (GBP) |
Funding ID | EP/L005913/1 |
Organisation | Engineering and Physical Sciences Research Council (EPSRC) |
Sector | Public |
Country | United Kingdom |
Start | 01/2014 |
End | 09/2019 |
Description | ERC Advanced Grant |
Amount | € 2,666,684 (EUR) |
Funding ID | 290966 |
Organisation | European Research Council (ERC) |
Sector | Public |
Country | Belgium |
Start | 02/2012 |
End | 01/2017 |