EIPAM Midterm Report
(added - 28/03/2007)  


EIPAM is a five year ESF programme that explores how electrons may be used to both manipulate molecules and initiate chemistry in complex molecular systems including clusters and surfaces. The programme brings together both experimentalists and theorists from a wide range of disciplines including physics, chemistry, engineering and biology. In its first three years the programme has developed rapidly bringing together researchers from 15 European Countries to discuss and build collaborative research projects leading to over 100 publications. The Programme has supported 38 staff exchanges including several longer term (up to six month) research fellowships. In September 2006 the Programme was responsible for initiating a European-Australia research co-operation that has been awarded a major grant from the Australian government for a collaborative research in electron and positron physics. The Programme has also acted as the catalyst for several further applications for transnational funding (with a COST Action on Electron Chemical Controlled lithography being awarded in 2006 – to commence in 2007)and will provide a major impetus for applications under forthcoming Framework VII Programme. Finally, but crucially, the programme has sought to develop links with more applied communities and in 2007 a meeting was held with researchers from Japanese plasma processing community to explore how basic research in electron control may be used to assist the development of nanoscale device fabrication using plasma technology.

1. Programme Objectives

The ability to understand, manipulate and control chemical reactions at the molecular level is one of the great challenges of modern research. Since chemical processes are dominant in most areas of science and technology the ability to control their pathways provides exciting new opportunities that may be exploited by both the research and technological communities. Such ‘single molecule engineering’ requires selective bond cleavage in target molecules to allow subsequent management of the local site chemistry. Since electrons are ubiquitous in nature and electron induced reactions (in the gaseous phase, on surfaces and in the condensed phase) initiate and drive the basic physical-chemical processes in many areas of science and technology from industrial plasmas to living tissues our ability to control electron interactions provides exciting new opportunities that can now be exploited by both the research and technological communities. For example, the development of the Scanning Tunnel Microscope (STM) -an electron emitter- has introduced the capability of atomic-scale imaging, analysis and individual atomic/molecular manipulation providing a new technology that has the opportunity to revolutionize the scientific approach in many aspects of both the material and life sciences.

Europe remains at the forefront of such pioneering research but, in contrast to the USA and Japan, the European research effort has, to date, been somewhat fragmented and coordination was rudimentary. The ESF supported EIPAM programme aims to bring together Europe's leading experimental and theoretical groups in a large-scale, multidisciplinary and collaborative research programme that will both maintain its international excellence and establish Europe as the centre for investigations of molecular control through electron processing with direct relevance in many areas from the basic sciences to industrial applications.

EIPAM based research is focused in four inter-linked scientific strands namely the study of:

  1. The study of electron induced reactions in the gaseous phase to determine single electron/isolated molecule interactions.
  2. The study of electron induced reactions as a function of phase including study of molecular clusters to investigate binary collisions and the study of electron induced processes on surfaces and in thin films.
  3. The application of STM technology to electron induced manipulation of single molecules on surfaces and
  4. Since the above are primarily experimental strands there is a fourth strand that coordinates theoretical and modelling of these processes.

2. Results achieved to date

Progress has been made in all these areas of research. Space limitations do not allow a comprehensive review of all the research that has been enabled under EIPAM so only a few highlights will be presented here.

Strand 1 Some of the most dramatic progress in the Programme has been in the study of electron scattering from bio-molecules in particular the DNA bases adenine, cytosine, guanine, thymine and RNA base uracil and, most recently, the larger biomolecules including glycine, simple sugars and acids. EIPAM partners (University of Innsbruck and Free University of Berlin) have shown that dissociative electron attachment is a dominant process at low electron energies and is both bond (C-H versus N-H) and site selective (N1-H versus N3-H and C6-H versus CH3) in the DNA bases. These pioneering results (reported in several PRL publications) suggest that may be possible to explore DNA damage at a basic molecular level. Indeed recent work by Berlin, Innsbruck and Open University groups has demonstrated a correlation between electron attachment rates to biomolecules and their carcinogenicity and may be used to suggest new compounds to be adopted in radiation therapy as treatment enhancing sensitizers, e.g. 5-bromouracil. We have also started an extensive study of electron interactions with water and the conduct of detailed gas phase dissociative electron attachment experiments to water (University of Innsbruck and Open University since water is the atypical biomolecule playing a central role to most biochemical processes. These experiments have been complemented by detailed theoretical calculations (University College London and Sapienza University,Rome) see below (strand 4). Such pioneering research has led to an active and growing international research community, one in which the EU is recognised as amongst the most active and leading members.

Strand 2 The second highlight concerns the potential of slow electrons to act as a soft tool to control chemical reactions in the condensed phase. By setting the energy of a well defined electron beam to values below 3 eV it has been shown that it is possible to initiate chemistry at very low incident energies - energies less than that predicted to rupture chemical bonds. This low energy chemistry is driven by the process of dissociative electron attachment (DEA). DEA fragments may initiate further chemical reactions. For example in a CH3Cl/NF3 cluster F- from NF3 reacts with CH3Cl by F- + CH3Cl ® CH3F + Cl-. An identical process may occur on a multilayer of co-deposited CH3Cl and NF3.Cl- desorbs from the film leaving CH3F so a multilayer may be chemically converted into pure film of another chemical species. Chemical reactivity has also been induced following electron irradiation of a mixture of ammonia and acetic acid at 25K. Amongst the irradiation products is the amino acid, glycine. These results further reveal the great ability of low energy electrons to initiate chemical modification of complex condensed ices at very low temperature. This research has been highlighted in Chemical Science and Chemical World. Electron-induced reactions can also bind specific functional groups to a surface in a controlled way. DEA of acetonitrile CH3CN + e- ® CH2CN- + H being used in the functionalization of hydrogenated diamond to attach organic groups to surfaces. Such experiments suggest that it is possible to manipulate molecular reactions on surfaces using low energy electrons. This research has great significance in the nanotechonology area where ‘nanoscale lithography’ may be induced by electron patterning (perhaps using scanning tunnel microscopes). Such DEA induced processing has been entitled Electron induced chemical lithography and is the topic of a European Science Foundation COST Action which was ranked as the leading chemistry proposal and will commence later in 2007.

Strand 3 Members of the EIPAM programme include Europe’s leading research centres in Scanning Tunnel Microscopy who are seeking to develop the STM as a chemical tool. For many years STMs have lacked chemical specificity, requiring complementary spectroscopic tools to identify the chemical species being imaged. However, recently STM–IETS (STM Inelastic Electron Tunnelling Spectroscopy) has been developed to measure the vibrational spectrum of a single molecule, allowing STMs to be used as a tool for chemical analysis of single molecules. EIPAM members at the University of Toulouse, University of Liverpool and Free University of Berlin have been at the forefront of this research.(e.g. N Lorente, J J Pascual and H Ueda Surface Science 593 122-132 (2005).

Strand 4 Methodology and general purpose codes, built upon existing codes constructed by teams in the network, have been developed to study fundamental electron interactions with increasingly complex molecules leading to excitation and dissociation. Recently Researchers at University College London (UCL) and Open University have developed their computational codes to study larger molecular systems with first results on tetrahydrofuran being presented at the EPIAM annual meeting. The UCL group has also reported the first results for electron induced dissociation of the water molecule. The Research group in Sapienza University Rome (F Gianturco et al) have performed the first calculations on complex biological molecules (glycine) pioneering new methods for probing radiation damage studies at the molecular level. Researchers in Prague have developed a computational scheme based on the Discrete Momentum Representation to derive energy loss spectra and a model, based on the quantum defect theory approach to electron-polar molecule collisions, to derive the first set of data for state-to-state rotationally inelastic scattering cross-sections. This research has been greatly advanced by the provision of longer fellowships supported by the EIPAM programme. In addition the programme has helped to reinvigorate an EU programme of positron based research with one EIPAM Fellow (K Franz) now developing UK based R matrix code for positron-molecule scattering. This in turn assisted in the recent EU Australia collaborative award on electron/positron chemistry with the newly established Centre for Antimatter ¬Matter Studies

Meetings/Exchanges etc

As part of the EIPAM programme we have established an annual series of meetings. The first was held in Viterbo. Italy 25-30 June 2005, the Second in Valletta Malta 16-20 September 2006 the third will be held in Iceland 25-29 May 2007. These meetings have provided a unique forum for interdisciplinary discussions between STM surface science and atomic and molecular communities. At the EIPAM06 meeting we signed a Memorandum of Understanding with colleagues in Australia which formed part of an application to the Australian Government for a collaborative programme in Electron and Positron induced chemistry. This was awarded in November 2006 and will start in June 2007 for a three year period supporting staff exchanges and an annual meeting (which when in Europe will be part of the EIPAM programme). In March 2007 in Belgrade we held a collaborative meeting with Japanese Colleagues as part of the EU-Japan Plasma Processing Conference series to explore how basic research in electron control may be used to assist the development of nanoscale device fabrication using plasma technology. EIPAM also supported the Low Energy Electron Molecule Interactions (LEEMI) meeting in Smolenice, Slovakia 6-10 October, 2005. Day schools in STM were arranged in Berlin and Birmingham in 2005. A special meeting/school was arranged for young theoreticians in Prague February 14-18 2005 to discuss future directions in electron molecule theory. Several members of the EIPAM community also participated inthe ESF sponsored meeting Biomolecules from Gas Phase Properties to the Actions Relevant to Living Cells Obergurgl, Austria, 27th June – 1st July, 2006.

The Steering Committee determined that a major proportion of the budget should be used for staff exchanges and establishing short term fellowships to allow research teams in Europe to develop collaborations and formulate joint research programmes. These have been very successful and very popular. We have particularly geared many of these visits at younger scientists, allowing them access to facilities that they do not have in their own Universities. Such visits have been (and are) extremely useful parts of their PhD programme ( e.g I Bald, J Kopyra, I Ipolyi, J Orszagh, A Stypczynska, F Rondino, Al Milosavljevic, G Kashenock, W Barszczewska l Kolorenc M Tarana H Flosadóttir, R Parifita, B Mielewska, A Mauracher and I Dabkowska or Postdoctoral Research (P Cicman, R Curik, L Feketeova, P Kendall. T Mikoviny, P Holtom, T Hoffmann, K Franz, M Thoss, B Pezler and J Franz ). Senior staff also exploited the opportunities for short visits to develop collaborations (O Ingolfsson, Rene Kalus, P Limao-Vieira, M Ya Amusia, C Mayhew, J Horacek, G Karwasz, A Arnau, J D Skalny and R Curik).

3. European Added Value and Visibility of the Programme Achieved to Date

Whilst not wishing to overplay the role of the ESF Programme in the wider EU/International research programme we strongly believe that the opportunities provided by the Programme have, in the last two years, provided an essential part of the emergence of the EU community as the world leader in electron driven research. Although there are, of course, centres of research excellence in the USA, Canada and Australia it is now the European research community that is leading much of the international research agenda, particularly in study of electron interactions with biomolecules and the development of electron induced chemistry/lithography. This was the primary aim of the ESF Programme and we believe that the ability to develop joint research projects, exchange staff and hold regular well funded meetings has greatly aided this process. The recent meeting with Japanese Plasma research/industry and the funding of the Joint EU Australia programme in Electron and Positron research (by the Australian Government) are, we believe testament to this leadership.

4. Programme Finances and Management

The financial expenditure is reported in the Appendices. As Stated above we have sought to provide a significant part of the budget towards visits and Fellowships whilst hosting one major meeting each year, and where appropriate supporting smaller strategic workshops. We wish to continue this spend pattern in the future. The growing number of publications recognising EIPAM as a source of support we feel justifies this and represent extremely good value for money (for some 80 papers to date a cost of <5000 Euros per paper !). The Management Structure has operated without difficulty, the Steering Commitee meeting once a year at the Annual EIPAM Meeting (and for this mid-term review at another convenient conference in Madrid in February 2007) all other business was conducted by email.There have been some changes in Membership of the Steering Committee (addition of Prof O Ingolfson for Iceland, the departure of Prof M Persson from Sweden to Liverpool, UK (to be replaced by Prof M Larsson, Stockholm) replacement of P Scheier for T Maerk (Austria) P Limao-Vieira for Portugal, Prof G Garcia for Spain). We also welcomed (non voting) representatives for France (A Lafosse/G Dujardin) and Italy (F Gianturco) even though their countries had not signed the programme since it is important to have the research of these countries represented in the Science plan. Finally we would like to note the excellent support provided by Ms B Harker at Open University who acts as EIPAM Secretary; Dr N C Jones Aarhus Denmark who acts as Webmaster and Chantal Durant at the ESF whose efficiency and help in ensuring the smooth operation of the programme is greatly appreciated.

5. Publicity

The programme has its own website (www.isa.au.dk/eipam) which has proven to be very successful in attracting new groups interest in the programme and developing applications for visits/fellowships. We do note that we failed to produce a brochure and plan this in the summer of 2007. We are also negotiating a book of review papers with a commercial publisher with the intention of publication in late 2008. In future EIPAM conference proceedings may be part of the Journal of Physics Conference Series. We would also note that several participants have had their work featured in their national media (e.g. Teams in Free University Berlin and University of Innsbruck).

6. Forward Look

Despite the significant advances made by the Programme we believe that there are several essential objectives still to be met.

  1. Further and deeper integration of the gas phase and surface phase communities.
  2. Development and integration of the STM community into the chemical control community, to date to often we are separated by difficulties in language and mutual understanding. This is essential if we are to develop real electron chemical control lithography.
  3. Development of the basic research into applications- for example chemical change in low temperature ices induced by electron impact is now believed to be a key process in astrochemisty while further understanding of role of electrons in radiation damage of DNA and other biomaterials is essential for developing new therapeutic methods.
  4. The age profile amongst the senior staff in the field is such that several will retire in the next five years, it is therefore essential that younger staff are able to assume leadership roles (both scientifically and managerially). Therefore EIPAM seeks to encourage/develop new academic staff and new groups through staff exchanges and joining the Steering committee. We therefore plan to host meetings at new groups (e.g. EIPAM07 in Iceland) and encourage Staff exchanges (e.g. from Eastern European and Balkan countries).

There are also several areas of research that are emerging from recent research conducted by the programme.

  1. The study of electron interactions with complex molecules seeded in clusters. A technique developed by University of Innsbruck to study biomolecuels such as nucleobases under conditions more appropriate for mimicking electron damage in cellular systems .
  2. The preparation of larger biomolecules (e.g amino acids and phosphates) in the gas phase.
  3. The role of morphology on electron induced chemistry in thin films and ices for example in the formation of glycine in binary films (CO2 and ammonia, CO2 and methylamine; acetic acid and ammonia).
  4. The development of STMs a chemical as well as a manipulation tool to allow site and bond selective chemistry.
  5. The development of theoretical techniques to larger more complex molecules.

We also wish to develop the remit of the EIPAM programme to (i) include positron studies and (ii) form closer interactions with plasma research community.
Positron interactions with matter have both applied applications (e.g. their use in medical therapy and as a tool for surface analysis) and provide exciting new insights into the interaction of simple leptons with molecules (the processes of annihilation and positronium formation being introduced in positron interactions). Recently a large scale Centre for Antimatter-Matter Studies (http://www.positron.edu.au/index.html) has been established in Canberra Australia and will be linked to EIPAM through provision of a three year $650,000 Network on Electron and Positron Chemistry.

Electron induced processes drive most of the fundamental physical and chemical processes in technological plasmas (e.g. those used in lighting, semiconductor chip manufacture, ozone production for sterilisation etc). The development of the next generation of plasma sources requires a more detailed knowledge of the electron interactions for example Japanese industry is exploring the development of electronegative plasmas as a tool for nanoscale technology (e.g. ‘Ultimate top-down etching processes for future nanoscale devices: Advanced neutral-beam etching’ S JAPANESE JOURNAL OF APPLIED PHYSICS 45 2395-2407 (2006), hence the development of EIPAM studies in collaboration with the plasma community needs ot be developed.

In accordance with these two additional projects we therefore envisage holding workshops on these topics in 2008-9.

Professor N J Mason on behalf of the EIPAM Steering Committee March 2007