This volume is the latest of the "Kirchberg-Proceedings". The previous 11 International Winterschools on Electronic Properties of Novel Materials, all held in Kirchberg, Austria, were devoted to conducting polymers, high temperature superconductors, fullerenes, and carbon nanotubes. Fullerenes and nanotubes are still in the center of interest, but the topic of the school and the proceedings is molecular nanostructures in general. The organizers have attempted to treat carbon nanostructures as a special case of molecular nanostructures, which also include silicon clusters, gold clusters, vanadium oxide tubes, and many others. The Winterschool provides a platform for reviewing and discussing new developments in the field of molecular nanostructures and their applications. Materials discussed include fullerenes, fullerene-derived structures, carbonaceous nanotubes, non-carbonaceous nanotubes, layer by layer systems, molecular clusters, new phases of carbon, endohedral compounds and related materials. The book aims to give an overview of the current status of fullerenes, carbon-nanotubes and related molecular nanostructures. The majority of the contributions present the latest results of experiments and calculations conducted in the field. However, about a dozen contain some degree of instructional material which even newcomers will benefit from.

This volume contains the proceedings of the NATO Advanced Research Workshop on "Atomic and Molecular Wires". It was sponsored by the Ministry of Scientific Affairs Division special program on Nanoscale Science with the support of the CNRS and the Max Planck Institute. Scientists working or interested in the properties of wires at a subnanoscale were brought together in Les Houches (France) from 6 to 10 May 1996. Subnanoscale wires can be fabricated either by surface physicists (atomic wires) or by synthetic chemists (molecular wires). Both communities present their foremost advances using, for example, STM to assemble atomic lines atom for atom, to fabricate a mask for such a line or using the wide range of chemical synthesis techniques to obtain long, rigid and conjugated oligomers. Interconnecting such tiny wires to sources (voltage, current) continues to demand a great technological effort. But nanolithography associated with microfabrication or STM are now clearly identified paths for measuring the electrical resistance of an atomic or a molecular wire. The first measurements have been reported on Xe , benzene, C ' di(phenylene-ethynylene) showing 2 60 the need for a deeper understanding of transport phenomena through subnanowires. Such transport phenomena like tunnel (off-resonance) transport and Coulomb blockade have been discussed by theorists with an emphasis on the exponential decrease of the tunnel current with the wire length versus the ballistic regime of transport.

The International Winter School on Electronic Properties of Conjugated Polymers held March 14-21,1987, in Kirchberg (Austria) was a sequel to a meeting held in Kirchberg two years before on a similar subject. The 1987 winter school was organized in cooperation with the "Bundesministerium fiir Wissenschaft und Forschung" in Austria and the "Bundesministerium fiir Forschung und Technologie" in the Federal Republic of Germany. The basic idea of the meeting was to provide an opportunity for experienced scientists from universities and industry to discuss their most recent re- sults and for students and young scientists to inform themselves about the present state of the research in this field. As in 1985, the scientific interest was concentrated on the electronic structure of various conjugated polymers and related compounds. The focus of interest in the field now appears to have broadened and cov- ers not only conductivity and relaxation phenomena of polyacetylene but also nonlinear optical properties, highly oriented and single-crystal poly- mers, and electrochemical and opto-electrochemical properties of special materials such as polypyrrole and polyaniline. Exciting results on conduc- tivity - the mass specific conductivity (i.e., the conductivity divided by the density) of polyacetylene is more than twice that of copper (!) - and a detailed interpretation of the meaning of conjugation length are reported.

This volume contains the proceedings of the NATO Advanced Research Workshop on "Atomic and Molecular Wires". It was sponsored by the Ministry of Scientific Affairs Division special program on Nanoscale Science with the support of the CNRS and the Max Planck Institute. Scientists working or interested in the properties of wires at a subnanoscale were brought together in Les Houches (France) from 6 to 10 May 1996. Subnanoscale wires can be fabricated either by surface physicists (atomic wires) or by synthetic chemists (molecular wires). Both communities present their foremost advances using, for example, STM to assemble atomic lines atom for atom, to fabricate a mask for such a line or using the wide range of chemical synthesis techniques to obtain long, rigid and conjugated oligomers. Interconnecting such tiny wires to sources (voltage, current) continues to demand a great technological effort. But nanolithography associated with microfabrication or STM are now clearly identified paths for measuring the electrical resistance of an atomic or a molecular wire. The first measurements have been reported on Xe , benzene, C ' di(phenylene-ethynylene) showing 2 60 the need for a deeper understanding of transport phenomena through subnanowires. Such transport phenomena like tunnel (off-resonance) transport and Coulomb blockade have been discussed by theorists with an emphasis on the exponential decrease of the tunnel current with the wire length versus the ballistic regime of transport.

Electronic Properties of Fullerenes and other Novel Materials gives an overview of the state-of-the-art research. It presents most recent results on preparation, experimental analysis by electron spectroscopy, infrared and Raman spectroscopy, luminescence, and nonlinear optical, as well as possible technological applications. Emphasis is also placed on the superconducting properties of Fullerenes. The introductory and advanced contributions provide a good survey of the current status of this rapidly developing field.

The International Winter School on Electronic Properties of Polymers and Re- lated Compounds, held March 11-18, 1989, in Kirchberg (Austria), was a sequel to two meetings on similar subjects held there two and four years be- fore. The 1989 winter school was again organized in cooperation with the "Bundesministerium flir Wissenschaft und Forschung" in Austria, and with the "Bundesministerium fUr Forschung und Technologie" in the Federal Republic of Germany. The basic idea of the meeting was to provide an opportunity for experienced scientists from universities and industry to discuss their most recent results and for students and young scientists to become familiar with the present status of research and applications in the field. Like the previous winter schools, this one concentrated on the electronic structure and application potentialities of polymers. A purely tutorial contribu- tion on high-temperature supercondutors was included. Special attention was paid this time to our present theoretical understanding of the electronic struc- ture of polymers in general, the role of disorder and the nature of the doping process in particular. Accordingly, two discussion meetings were held on the stability of quasiparticles in conjugated polymers and on the thermochromic phase transition in alkylated thiophenes. As a general result, disorder and con- jugation length were recognized as fundamental properties, not only for the stability of the quasiparticles but also for linear and nonlinear optics, transport, phototransport, magnetic properties, lattice dynamics, etc.

The International Winter School on Electronic Properties of Polymers Orien tation and Dimensionality of Conjugated Systems, held March 9-16, 1991, in Kirchberg, ('lYrol) Austria, was a sequel to three meetings on similar subjects held there. The 1991 winter school was again organized in cooperation with the "Bundesministerium fUr Wissenschaft und Forschung" in Austria, and with the "Bundesministerium fUr Forschung und Technologie" in the Federal Republic of Germany. The basic idea of the meeting was to provide an opportunity for experienced scientists from universities and industry to discuss their most re cent results and for students and young scientists to become familiar with the present status of research and applications in the field. Like the previous winter schools on polymers, this one concentrated on the electronic structure and potential for application of polymers with conjugated double bonds. This time, however, special attention was paid to the effects of orientation and dimensionality. Anisotropy of the electric conductivity in stretch-oriented samples and whether the transport mechanisms are one-, two-, or three-dimensional or might even have a "fractal dimensionality" were there fore central topics. The problem of orientation was extended to systems such as Langmuir-Blodgett films and other layered structures. Accordingly, thin films were the focus of most of the application oriented contributions. Whereas in the previous winter schools discussions on applications dealt with "large volume applications" such as electromagnetic shielding and energy storage, this time "molecular materials for electronics" and prospects of "molecular electronics" were at the center of interest."

At the International Winter School on "Electronic Properties of Polymers and Related Compounds" particular attention was paid to a very new and special field in polymer research. It is concerned with the study of the electronic structure of polymers and with physical and chemical properties directly re lated to this structure. In particular, tutorial and research contributions on electrical, electrochemical, optical, magnetic, lattice dynamical and structural properties were presented. In addition, review reports on related topics such as charge transfer complexes and linear-chain compounds (transi tion-metal trichalcogenides) were included. In two discussion meEjtings, the special role of polyacetylene and possible present and future applications of the electronic properties of polymers, as e.g. conductors or as electrodes in electrochemical cells, were elucidated. The electronic properties of polymers cover a wide range of research problems which are of particular interest for polymers with a 1T-electron system. Thus, a great part of the work presented was concerned with conjuga ted systems. Additional presentations dealt with other systems such as bio polymers, photopolymers or electrets, which are of significant scientific and technical importance. It was demonstrated how their electronic proper ties are increasingly being investigated from a fundamental point of view by applying known concepts of snlid-state science."