2EURONanochem Eurocore proposal co-ordinated by Professor G Dujardin Laboratoire de Photophysique Moléculaire, Université de ParisXI,FRANCEProfessor G GerberFakultät für Physik und Astronomie, Universität Würzburg,GERMANYProfessor F GianturcoDepartment of Chemistry; Università di Roma "La Sapienza; ITALYProfessor Nigel J Mason (co-ordinator)Department of Physics & Astronomy, Open University, UNITED KINGDOMProfessor T D MaerkInstitut Ionenphysik, University of Innsbruck, AUSTRIA
3EURONanochem Problem: Conventional chemical reactions are mainly controlledbased on conventional termodynamic variables.Aim:To control chemical reactions through the ability toselect the pathways of molecular dissociation.Methodology;Control using photodissociation;Control using electron induced fragmentation;Provide spatial control through STM
4EURONanochem Brief description: Chemical control with photons; Using laser pulses with a duration of femtoseconds/picoseconds, the timescale on which the atoms in a molecule move, to manipulate molecular wavepackets and control dissociation pathwaysChemical control using very low energy electrons to dissociate the molecular target at well defined reaction sitesThe application of STM technology to electron induced manipulation of single molecules on surfaces
5Bond Selectivity using photons Process of “coherent control”. Exploits the optical phase of coherent laser light, coined “coherent control”. Such techniques employ quantum mechanical interference between the pathways leading to products of a chemical reaction.One fs laser pulse can induce the molecule only to bend, while a different light pulse will cause it only to stretch. Hence can select specific vibrations in molecules leading to specific bond ruptures in turn opening possibility of controlling chemical reactions.
8Optimal Control Experiments molecular gas phase photodissociation(selective bond-cleavage)selective excitation of complex moleculesin the liquid phasephotoisomerization of complex moleculesselective bond-forming reactions
9selectivity?selectivity?Bond CleavageBond FormationFemtosecond Laser-Assisted Catalytic Surface Reactions of Syngas (CO+H2) and their Optimization by Tailored Laser Pulses,Gerber et al., Wuerzburg
10EURONanochem: The programme Topic 1; Chemical Control using light Develop ultrafast femtosecond chemistry for selective bond bydeveloping automated optimization of branching ratios of gas phase photodissociation reactionsdevelop the technique of femtosecond polarization pulse shaping to study the attachment of functional groups to surfaces of materials such as semiconductors or molecular self-assembled monolayers;extending present studies into the liquid phase to explore more biologically relevant chemical processes andcomplementing these experiments by theoretical studies.
11Bond Selectivity using Electrons Process of Dissociative Electron Attachment (Low electron energy!!!)
12Electron Induced Chemistry; Chemical Control at the Molecular Level Selective C-Cl bondcleavage at 0 eVSelective C-F bondcleavage at 3.2 eV
13Low-energy electrons induce single- and double-strand breaks in DNA An electron initially binds to DNA forming transient molecular anion. This anion transforms in a sequence of processes, leading to DNA strand breaks.
14Example of Chemical surface transformations DEA produces products that subsequently react on the surfaceE.g. Irradiate film of NF3 and CH3ClForm CH3Fe-e-CH3Clno ionsCl-e-(NF3)n•(CH3Cl)mF-
16Control via e--induced chemistry developing electron lithography Basice--moleculeinteractionsResonancesE0 dependencee--induced chemistryCross sectionsTypical reactions and productsReaction sequencesSurface functionalizationReactions at the interface of materialsModification of materials properties- structural - electrical- permeability- optical
17EURONanochem: The programme Topic 2; Chemical Control using electronsto study intermolecular reactions leading to controlled coupling of a reactive fragment to another materialto study the attachment of functional groups to surfaces of materials such as semiconductors or molecular self-assembled monolayers;to explore the potential of these reactions for chemical lithography and e-beam techniques andto guide these experiments by theoretical studies, i.e. to predict which of different possible intermolecular reactions is energetically the most likely.
20Sloan and Palmer Nature 434, Electron excitation and dissociation of individual oriented chlorobenzene molecules on a Si(111)-7 7 surfaceThe first electron interacts with the chlorobenzene molecule; the molecule is left vibrationally excited (specifically, the C−Cl wag mode is excited); the second electron interacts with the molecule before the C−Cl wag mode has fully relaxed, leading to dissociation of the C−Cl bond by DEA;
21EURONanochem: The programme Topic 3; Chemical Control on the nanoscaleSTM experiments on prototype organic molecules adsorbed on surfaces with the aim of fabricating complex molecular architectures of any desired shape and size on the surface.Electron Simulated Desorption (ESD) and High Resolution Electron Energy Loss Spectroscopy (HREELS) experiments on to identify the ion resonances and the electronic transitions involved in the excitation mechanisms as well as the final products of the molecular reactions.Development of a comprehensive simulation of the coupled surface and STM tip system to model excitation and bond breaking of single molecules by STM-IET.Molecular dynamical calculations to unravel details of atomic and molecular manipulation at surfaces, leading to lateral motion, bond making or breaking, and desorption of the adsorbates.
22EURONanochem: The programme Exploitation:To explore how such fundamental techniques may be developed as a commercially viable technique.In developing such chemical control we also wish to exploit it in other modern technologies such as quantum information, nanotechnology and the biosciences.
23EURONanochem: The programme OrganisationalEstablishment of a European forum for discussion of challenges and opportunities in the development of chemical control.To further integration of European academic and industrial research communities in developing a common research framework in the utilisation of chemical control.To Encourage younger researchers and develop new groups (e.g in Central/Eastern Europe and the Balkans.To develop a coherent research programme that will allow methodologies for control of molecular dissociation pathways to be developed.To integrate researchers from femtosecond chemistry, electron chemistry, and scanning tunnel microscopy and share expertise and skills.
24EURONanochem: The programme Hosting an annual Meeting in Europe (link to ESF EIPAM and COST ECCL)Develop international links ( USA; Japan and Australia)Training -workshops and schoolsIndustrial forums