Schedule. 15: Registration 15: Theory 1: F. Mercuri Dinner

Transcription

1 Schedule Sunday, January 30 15: Registration 15: Theory 1: F. Mercuri Dinner Monday, January 30 08: Theory 2: B. Mennucci 10: Theory 3: D. Sebastiani Theory 4: F. Mercuri Dinner Flash Presentations - Poster session Tuesday, February 1 08: Methods 1: G.P. Spada 10: Methods 2: N. Armaroli Workshop : J. Siegel Dinner Special Event: N. Armaroli Wednesday, February 2 08: Applications 1: M. Benaglia 10: Applications 2: R.P. Sijbesma Methods 3: K. Müller Dinner Flash Presentations - Poster session Thursday, February 3 08: Applications 3: G. Farinola 10: Applications 4: M. Maggini Applications 5: M. Prato Social Dinner Friday, February 4 08: Methods 4: P. Samorì 10: Final test Closing remarks

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3 Session 1 (January 30 th and 31 th ) Computational Methods Modeling of low-dimensional carbon nanostructures. Francesco Mercuri (Perugia, IT) The lecture will focus on the application of computational sciences in the study of carbon nanostructures, such as carbon nanotubes and graphene. Particular attention will be devoted to the use of state-of-the-art computational approaches for the modeling of systemswith potential use in advanced applications, such as materials for nanoelectronics or organic photovoltaics. The intrinsical complexity of the problem under study and the accuracy required to compare theory with the experiment usually turns into a considerable computational demand, which is faced with the help of "smart" modeling criteria,based on traditional chemistry principles, and with the use of tailored theoretical approaches. Computational methods for organic materials: from classical force fields to quantum mechanics. Benedetta Mennucci (Pisa, IT) The lecture will introduce the basic aspects of the main computational methods used in computational chemistry. Both classical (molecular mechanics) and quantum mechanical levels of descriptions will be considered as well as their possible combinations. Limits and potentialities of the different methods will be briefly discussed. Examples of applications of the same methods will be given with particular attention to the simulation of properties and processes of organic systems in solution or embedded in more complex environments. Molecular Structure and Dynamics of Functional Materials from First-Principles Spectroscopy. Daniel Sebastiani (Berlin, D) The lecture will introduce the concept of computational spectroscopy as a complementary tool for the elucidation of atomic structure and molecular dynamics in complex functional materials. Established computational approaches based on electronic structure theory (ab-initio) have either the problem of being computationally very expensive, or of being approximative, at least in parts. The approximations lead to errors in the potential energy surface, which have an impact on the resulting structural and dynamical properties. With the help of computational spectroscopy, we can directly compare to experimental observables and hence provide a way to verify (or falsify) structural and dynamical features of complex supramolecular systems.

4 Session 2 (February 1 st, 2 nd and 4 th ) Analytical Methods The Use of Circular Dichroism Spectroscopy for Studying the Chiral Molecular Self-Assembly A case study: the guanine-based supramolecular systems. Gian Piero Spada (Bologna, IT) Self-assembly plays an important role in the formation of many chiral biological structures and in the preparation of chiral functional materials. Therefore the control of chirality in synthetic or biological self-assembled systems is important either for the comprehension of the recognition phenomena or the obtainment of materials with predictable and controllable properties. Circular dichroism were developed to study molecular chirality, however, due to its outstanding sensitivity to chiral perturbations of the system under investigation, it has been extended more recently to supramolecular chemistry. In particular, self-assembly processes leading to the formation of chiral supramolecular architectures (and eventually to gels or liquid crystal phases) can be monitored by CD.1 As an example of CD investigation of the molecular self-assembly, I selected the case of guanine-based systems.2 G analogs have been used as building blocks for functional applications in supramolecular chemistry, material science and nanotechnology.3 The presentation gives a brief historical context of G self-assembly in water and then describes studies on lipophilic guanosine analogs in organic solvents. Depending on the experimental conditions, guanosine derivatives can undergo different self-assembly pathways and their chiral supramolecular structures may self-correlate to give a liquid crystalline order. Fundamental Methods In Photohcemistry and Photophysics. Nicola Armaroli (Bologna, IT) Steady-state and time resolved absorption and luminescence spectroscopic methods are the main tools to carry out research in photochemistry and photophysics. These branches of science deal with the interaction of matter with UV-Vis radiation, a phenomenon of central importance in many natural processes and technological applications. After having introduced some key concepts on electronic excited states and photoinduced energy- and electron transfer, a series of selected example taken for the literature will illustrate the wealth of information that can be obtained through these experimental methods and how this knowledge is important in fundamental as well as applied sciences. Solid-State NMR Spectroscopy in Materials Research. Klaus Müller (Trento, IT) A brief introduction to the basics of solid-state NMR spectroscopy will be given. Selected applications on various types of materials (e.g. polymer fuel cell membranes, guest-host compounds, inorganic-organic hybrid materials, ionic conductors) demonstrate the possibilities of modern solid-state NMR techniques for characterization of such materials on a molecular level. It is shown that solid-state NMR spectroscopy provides reliable data about the compositional and

5 structural features as well as the dynamic properties. Such information is a prerequisite for the correlation of the molecular behavior and distinct bulk properties of the materials under investigation, and puts the basis for a directed design and development of new materials with specific functional properties. Architecture vs. Function relationship in supramolecular nanomaterials for organic (opto)electronics. Paolo Samorì (Strasbourg, FR) Multifunctional materials are key in organic (opto)electronics. However, their practical use requires the optimization of the self-assembly of multimodular architectures at surfaces using nonconventional methods, their controlled manipulation and responsiveness to external stimuli, and the quantitative study of various physico-chemical properties at distinct length- and time-scales. My lecture will review recent results obtained in our laboratory in five different research themes: (i) Development of novel processing and post processing methods to produces highly ordered supramolecular electroactive architectures. While solvent vapour annealing post-treatments can be used to form millimetre long crystalline fibers of the semiconducting perylene-bis-dicarboximide (PDI) or hexa-peri-hexabenzocoronene, its combination with dipping made it possible to form PCBM single crystals with sizes of several tens of micrometers. (ii) Supramolecular scaffolding to control the position of functional units at surfaces and interfaces. This has been accomplished both using metallo-ligand interaction in anthracene incorporating molecular tectons, and employing H- bonding between guan(os)ine derivatives exposing oligothiophene moieties. (iii) Responsive interfaces which have been visualized on the sub-nm scale by Scanning Tunneling Microscopy (STM). We will show the first dynamer operaring at surfaces, being based on guanine derivatives dynamic self-assembly. We will also show prototypes of light-powered mechano-chemical switches operating at surfaces. Their bistable nature will be exployed to develope optically modulable nanoscopic and macroscopic junctions as explored by conducting AFM and Hg drop based junctions. (iv) Scanning Probe Microscopies beyond imaging to gain direct and quantitative insight into electronics processes in multicomponent architectures including in particular the Kelvin Probe Force Microscopy (KPFM) quantitative mapping of the photovoltaic activity in electron acceptor/donor blends, on the hundreds of nanometers and on the few nanometers scale. Further, the electrochemical local reduction of graphene oxide with and AFM tip followed by the C-AFM study of the electrical properties of the manipulated architecture will be presented. (iv) Supramolecular approaches to organic electronics allow improvement of the performance of devices. We will show some recent results we obtained like the tailoring of percolation parthways for charge transport in polycrystalline films for FETs.

6 Session 3 (February 2 nd and 3 rd ) Applications Recoverable and Recyclable Catalysts. Maurizio Benaglia (Milano, IT) The immobilization of the catalyst with the aim of facilitating the separation of the product from the catalyst, and thus the recovery and recycling of the latter, can be regarded as an important improvement for a catalytic process. The talk will cover the more relevant achievements in the field of supported catalysts, focusing on to the works of the last few years, with a special attention for chiral systems. Different classes of catalysts will be considered and discussed, different technologies and methodologies employed to develop a recoverable and recyclable catalyst will be compared. Self Assembly of Supramolecular Polymers. Rint P. Sijbesma (Eindhoven, NL) Since their introduction by Lehn in the early nineties, supramolecular polymers have grown from scientific curiosities to materials with a wide range of applications. The Lecture will introduce the basic concepts of supramolecular polymers and supramolecular polymerization, such as reversibility, degree of polymerization, isodesmic vs cooperative polymerizations, and cyclization. The non-covalent interactions that induce self-assembly of supramolecular polymers will be illustrated with relevant systems, and an overview will be given of current and future applications of this exciting class of materials. Organic semiconductors for electroluminescence and sensing. Gianluca Farinola (Bari, IT) The lecture will discuss how multilevel management of structural parameters of organic semiconductors enables fine tuning of properties for applications in organic electronics, focusing on electroluminescence and sensing. The control of molecular structure (conjugated backbone, substituents) and of intermolecular interactions in the solid state for tuning band gap and emission colour of electroluminescent materials will be discussed. Different strategies for combining multiple emitters of different colours to produce white electroluminescence will be also described, highlighting the potentialities of white organic light emitting diodes (WOLEDs) as low energy consumption lighting sources. Finally, functionalization of organic semiconductors with groups tailored for selective interactions with chemical or biological analytes will be presented as a structural modification to obtain materials for high performance optical and electrical sensing.

7 Sun & molecules: new energy for our future. Michele Maggini (Padova, IT) The last years have seen huge efforts to introduce organic materials as an alternative to inorganic semiconductors for the fabrication of flexible, lightweight organic photovoltaic devices. Chemistry is at the forefront of this challenge through the design and synthesis of functional molecular structures able to harvest the sunlight and undergo photon to current energy conversion. This presentation will highlight the characteristics of the most relevant chemical compounds that define the different classes of all-organic photovoltaic devices illustrating their potentials to reshape how we produce and use energy. Functionalization of Carbon Nanotubes for Materials and Nanomedical Applications: Synthesis and Challenges. Maurizio Prato (Trieste, IT) Nanometer-scale structures represent a novel and intriguing field, where scientists and engineers manipulate materials at the atomic and molecular levels to produce innovative materials for composites, electronic, sensing, and biomedical applications. Carbon nanomaterials such as carbon nanotubes constitute a relatively new class of materials exhibiting exceptional mechanical and electronic properties and are also promising candidates for gas storage and drug delivery. However, processing carbon nanotubes is severely limited by a number of inherent problems: purification from a variety of byproducts, difficult manipulation and low solubility in organic solvents and in water are only some of these problems. For these reasons, several strategies have been devised to make nanotubes easier materials. Covalent and supramolecular functionalization of carbon nanostructures are the basic synthetic techniques for solubilization and use in different fields such as donor-acceptor systems or drug delivery. The combination of nanotubes with various electron donors has led to a new generation of donor-acceptor nanohybrids which can be used for the development of carbon-based photovoltaic cells. Upon illumination, these systems give rise to fast charge separation and slow charge recombination. The results are so far very promising and further research in this field to obtain practical conversion of light energy into electricity is not only justified but also desirable. In addition, in combination with polyoxometalate catalysts, carbon nanotubes can serve as wires for the splitting of water molecules to give oxygen, but, especially, molecular hydrogen, ideal for clean energy generation. Also in biomedical applications carbon nanotubes are set to play an important role. Their use as drug delivery scaffolds and substrates for vaccines has already been demonstrated. Nanotubes functionalized with bioactive moieties are particularly suited for targeted drug delivery. In fact, not only they become less toxic, but also exhibit a high propensity to cross cell membranes. The use of carbon nanotubes as active substrates for neuronal growth has given so far very exciting results. Nanotubes are compatible with neurons, but especially they play a very interesting role in interneuron communication. The chemical modification of carbon nanotubes is a very young field, but the nanotubes represent today a class of materials expected to play a significant role in innovative discoveries. Future studies will determine the opportunities as well as the limitations of such materials.

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