Photo of John Turner

John Turner
Reader in Inorganic Physical Chemistry (Chemistry)
E:
T: +44 (0)1273 873915


Research

Research in the Turner group spans both synthetic work and detailed characterization of the structure of matter using advanced diffraction methods.

Further details can be found at the Group Web Site

 

Synthesis

Transition metal systems for small molecule activation

Economically important small molecules are typically strongly bound and unreactive under ambient conditions; reaction conditions are usually strenuous and thus necessarily energetically inefficient. Transition metals can mediate small molecule transformations, whether stoichiometric or catalytic, by supplying low energy pathways by which the necessary bond scission and formation processes can take place.

In general, scission of a chemical bond may be achieved in two ways: through removal of bonding density, the 'acidic' route, or through population of the antibonding orbitals - the 'basic' route. We explore both of these extrema with carefully designed transition metal systems, in order to discover new types of reactivity in both applied and academic contexts.

Skills that students develop when working in this area in the group include inert atmosphere synthetic methods, detailed spectroscopic analysis using primarily NMR spectroscopy and structural investigations using crystallography either in the Department or using user facilities in the UK, US and Europe. Synthetic and mechanistic results are also augmented with computational work where appropriate. Recent collaborators in this area include Prof. Linda H. Doerrer at Boston University and Prof. Jennifer C. Green at the University of Oxford.

Fluorine and Superacid Chemistry

Fluorine is the most reactive and therefore, in some senses, the most exciting element with which to work. The properties of fluorine-containing compounds are interesting and often anomalous when compared to either the oxygen-containing analogue or heavier halogen congeners.

We explore several aspects of the chemistry of fluorine, including magnetically interesting dense phase fluorides, fluoride glasses and reagents for gentle fluorine atom transfer in addition to more speculative work. A key feature is the use of chemie douce methods, involving anhydrous HF as a solvent.

Superacids are the strongest proton donors known; typical superacids include anhydrous HF, fluorosulphuric acid, FSO3H, fluoroantimonic acid, HSbF6 and 'Magic acid', FSO3H-SbF5. Reactivity that has been observed in superacidic media includes the H-atom exchange in hydrocarbons, including methane, C-H and C-C activation, the last two being the basis for superacidic cracking of hydrocarbons.

We study solutes in superacidic media and the pure fluids themselves using NMR spectroscopy, Raman scattering, infrared spectroscopy and diffraction from the liquid state using both neutrons and high energy X-rays.

Synthetic work in this area in the group is based on high vacuum techniques using all glass lines or the group's monel/stainless steel fluorine line. Work at neutron scattering facilities in the UK, Europe and the US adds an element of travel to this project. Collaborators include Prof. Ted Barnes (University of Tennessee), Prof. Dr. Alan Tennant (Hahn-Meitner Institute, Berlin), Prof. F. Javier Bermejo (University of the Basque Country, Bilbao) and Prof. Jeff Yarger (Arizona State University).

Structure

Applications of advanced diffraction techniques, liquid and magnetic structures

Diffraction using either X-rays or neutrons is the clearest method of determining the correlation functions that are present in condensed matter. We are particularly interested in the electron distributions in multi-centre bonds, including the hydrogen bond in fluids, superacids and models for biological systems. We also use neutron diffraction to determine the nuclear correlations in liquids and solutions.

 

D.Phil Position available

Applications are invited for D.Phil CASE studentship, sponsored by EPSRC and SEEDA, at the University of Sussex as part of a team led by Dr. G. A. Lawless, in collaboration with PPTek Ltd.

Applicants should have a 1st class Honours degree in Chemistry or Chemical Physics and research interests in some or all of the following areas:

  • small molecule activation at transition metal centres
  • organometallic synthesis and catalysis
  • zeolite chemistry
  • photochemistry


Applicants should send a letter expressing interest, a CV and the names of two referees to

g.a.lawless@sussex.ac.uk

prior to interview.