Time Resolved Solid State Structural Studies Across the Picosecond to Microsecond Time Domains

Lead Research Organisation: University of Bath
Department Name: Chemistry

Abstract

With the advent of new synchrotron facilities coupled with the advances in laser technology it is possible, for the first time, to carry out new types of experiment and develop cutting edge methodologies for studying the structures of species that are key to many chemical reactions but which have lifetimes ranging from only a few nanoseconds to a few microseconds. An understanding of the structure of these short-lived species will help in the design of new smart materials with potential applications in the electronics and sensor industries. To help with this understanding, in this projects we plan to develop techniques for making molecular movies so that we can watch how molecules change as they interact with rays of light from lasers. Many of the new materials used in the electronics industry are solids and it has long been recognised that the best way to determine the full three-dimensional structure at the atomic level of a crystalline solid is to use X-ray diffraction. Until now this crystallographic technique has only allowed the structure of the material to be determined at the beginning or end of a reaction, and not during it. However, using the high energy X-rays generated by the new diamond synchrotron coupled with the use of pulsed lasers, the situation has changed, and during the course of this project it will be possible to bring the dimension of time into the crystallographic experiment and obtain the full three-dimensional structures of molecules as they become excited when they interact with laser light. This new methodology is called photocrystallography .IR spectroscopy is another technique that has been used extensively for obtaining information on the structures of reactive species that have very short lifetimes, but until now, almost all the IR studies have been carried out in solution rather than in the solid state where many materials of interest to the electronics industry display their most interesting properties. In this project, we will, for the first time, develop IR methods of obtaining structural information on species with nanosecond lifetimes in the solid state. Thus, by combining the photocrystallographic and time resolved IR techniques we will be able to establish the structures of species with lifetimes in the nanosecond to microsecond range in a way that has never been possible before and obtain a wide range of new scientific information that will be of importance to chemists, physicists and material scientists. We will also provide top quality training for the Ph D student on the project in a range of crystallographic, spectroscopic and synthetic techniques, so that he/she will be in a unique position to develop this new area of science in the future.
 
Description We have developed combined time-resolved spectroscopic and crystallographic methods to study a series of materials with applications in the electronics industry under light irradiation or under pressure to establish how their structures and electronic states change. Essentially, we can "watch" the chemical processes as they happen in these important materials.
Exploitation Route Having developed these methods of measuring the structures (and hence the electronic properties) of these materials in their excited states, others can apply these methods to other key classes of material. In this way new materials can be designed and more energy efficient switches and sensors obtained.
Sectors Chemicals,Education,Electronics,Energy,Environment,Healthcare

 
Title Methods for determining the structures of materials that are metastable or have short lifetimes in the solid state using photocrystallographic methods 
Description We have developed single-crystal X-ray crystallographic methods for determining the structures of metastable materials using photocrystallographic methods. These methods have been adopted by other groups and photocrystallography is now a growing topic. 
Type Of Material Improvements to research infrastructure 
Year Produced 2010 
Provided To Others? Yes  
Impact We have established the structures of a range of coordination complexes that show linkage isomerism under photoactivation. The use of LEDs to photoactivate the materials is now in teh public domain and the methodology has been adopted by a number of research groups. 
 
Title Time resolved spectroscopic methods 
Description During this project we have developed time-resolved IR methods for studying the dynamics of inorganic and metallo-organic materials in the solid state. 
Type Of Material Improvements to research infrastructure 
Year Produced 2014 
Provided To Others? Yes  
Impact These methods are now available to other users of the Central Laser facility 
 
Description Workshop on how to write good papers 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Postgraduate students
Results and Impact A 2-day workshop at the RCaH organised for the post graduates and post doctoral workers at the RCaH to help them write better, high impact papers. Editors from leading journals were invited to give talks, and there were also group working sessions and individual mentoring.
Year(s) Of Engagement Activity 2016