Two dimensional supramolecular networks on insulators: structural organisation, fluorescence and host-guest interactions

This project focuses on the ability to control the organisation of molecules on the molecular level, to specifically determine their precise positioning and to understand the effect of their relative positions on their fluorescence. The study builds upon our recent discovery that it is possible to structurally characterise molecular arrays on insulating surfaces under atmospheric conditions with a high degree of precision by atomic force microscopy (AFM), moving beyond previous studies that used conducting surfaces. As a result we are now able to probe molecular properties, such as fluorescence, which were previously quenched by the supporting, conducting surface.

We now seek to understand to what degree these properties can be controlled and how entrapment of guest molecules within our arrays, which are porous, affects that fluorescence. We will develop a detailed understanding of the effect of guest trapping by the surface-based arrays and demonstrate that through change in the fluorescence signal we can specifically recognise trapped guest molecules working towards molecular-scale sensing systems.

Our research directly addresses the topics of self-assembly of new materials, in particular extended arrays. Our work is very closely aligned with the objectives of the EPSRC Grand Challenges in Chemistry, Directed Assemblies of Extended Structures with Targeted Properties and Physics, Nanoscale Design of Functional Materials, which envisage an increasingly important role for self-assembly approaches in the manufacture of new functional materials.

The EPSRC have recognized that controlling functional and structural properties at a level of complexity comparable with that displayed by biological systems is an extremely long term goal, which may require in excess of 20 years. However they have also recognised that self-assembly of materials has the potential for far-reaching economic impact. The objectives of our project, particularly our focus on determining the influence of guest molecules on host-guest fluorescence and our exploration of the potential of fluorescent 2D supramolecular networks for molecular recognition, are likely to come toward fruition the end of the three year project and we will seek to develop and exploit the impact of our research through the organization of a multi-disciplinary one-day meeting for both academic and industrial parties interested in the development of this research field and the emergent properties from the technology that we seek to develop.

The team have a strong track record in communicating their science to wider audiences and in using the media to publicise their research. We believe that the proposed research is ideal for public communication and therefore we will bid to present our research at the Royal Society Exhibition in the latter years of the project. A major impact from the research will be the output of trained researchers, 2 postdocs and a PhD student, whose training will be enhanced through their participation in an interdisciplinary grouping. This cohort of researchers will provide a highly significant impact through the availability of research staff to support an expansion of research into self-assembly in the UK over the next decade. Any results of commercial significance that arise, possibly related to synthetic methodology or development of theoretical models will be protected through the Business Partnership Unit (BPU) within the School of Chemistry at Nottingham.