Dr Richard Douthwaite

01904 324183
Email: richard.douthwaite@york.ac.uk

Molecular and materials chemistry, photocatalysis

The interests of the group encompass materials and molecular chemistry. Essentially we study the synthesis of molecules that can exhibit interesting reactivity or catalytic activity and also try to develop unusual routes to solid materials with photocatalytic application.

Current main lines of research are outlined below but please visit the group pages for more information.


Photocatalysis and Solar Energy Conversion

Photocatalysts are a class of material that mediate chemical reactions using photons as a source of energy. There are many potential uses including the degradation of chemicals detrimental to the environment, chemical synthesis, and the conversion of solar into chemical energy. We are interested in the later two applications and particularly the production of dihydrogen and dioxygen from water, which could potentially provide the basis for a clean fuel source with very low carbon emissions.

 

The concept is simple: to generate reducing (electrons) and oxidizing (holes) from excitation across a bandgap (Figure 1), which can subsequently be used for REDOX chemistry (e.g. water to dihydrogen and dioxygen). However, it is unlikely a single compound will be able to perform all the required steps efficiently (absorption across the visible spectrum, electron/hole migration to the surface, and catalysis of the chosen reaction, whilst remaining stable for a long time). Therefore 'engineered' materials composites are the more likely solution where more than one material can be used to perform one or two of the functions. We have recently built photocatalytic testing facilities and a microwave plasma reactor to help discover new materials for photocatalytic applications. The use of microwave-induced plasmas (MIP) builds on some of our earlier work exploring the synthesis of materials using microwave methods.

 

Figure 1.


New N-donor Ligands

A molecular synthetic project, the aim here is to prepare and investigate the synthesis and reactivity of complexes incorporating a class of N-donor ligands based on 1H-pyridin-(2E)-ylidenes (PYEs). These ligands are very easy to synthesise in one step and we have started to explore their chemistry. PYE type ligands appear to be strong donors and their structure renders the N-substituent (R1, Figure 2) close to the metal, which can control reactivity.

PYE complex

Figure 2. 


N-Heterocyclic Carbenes

A molecular synthetic project encompassing the development of new ligands based on N-heterocyclic carbenes (NHCs).  In related chemistry we have recently shown that NHC can add to unactivated imines to give a new class of nucleophilic alkene (Figure 3). The organic and organometallic chemistry of this very reactive molecule should be of interest for the preparation of new classes of N-heterocycles and also potentially chelating NHC-acyclic carbene complexes via insertion of a metal into the C=C double bond. 

NHC-imine reaction

Figure 3.