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.

Twin polymerization is a novel approach where two distinct polymers are produced from a single source monomer, thus being an excellent tool for the synthesis of hybrid materials. The author introduces the principles of various twin polymerization processes, their classification and practical use. The book is supplied with numerous individual examples, demonstrating the potential of this strategy in materials synthesis.

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.

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 High-Temperature Superconductors, held between March 7-14, 1992, in Kirchberg, (Tyrol) Austria, was the sixth in a series of meetings to be held at this venue. Four of the earlier meetings were dedicated to issues in the field of conducting polymers, while the winter school held in 1990 was devoted to the new discipline of high-T c superconductivity. This year's meeting constituted a forum not only for the large number of scientists engaged in high-Tc research, but also for those involved in the new and exciting field of fullerenes. Many of the issues raised during the earlier winter schools on conducting polymers, and the last one on high-T c superconductivity, have taken on a new significance in the light of the discovery of superconducting C materials. 60 The Kirchberg meetings are organized in the style of a school where expe rienced scientists from universities, research laboratories and industry have the opportunity to discuss their most recent results, and where students and young scientists can learn about the present status of research and applications from some of the most eminent workers in their field. In common with the previous winter school on high-Tc superconductors, the of the cuprate superconductors. present one focused on the electronic properties In addition, consideration was given to related compounds which are relevant to the understanding of the electronic structure of the cuprates in the normal state, to other oxide superconductors and to fulleride superconductors.

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."

This volume contains the proceedings of the International Winter School on Electronic Properties of High Temperature Superconductors, which was held March 3-10, 1990, in Kirchberg (Tyrol), Austria. This course was a sequel to three meetings on the subject of conducting polymers held there one, three and five years previously. The new topic was taken up since many of the scientists working on conducting polymers are now also actively interested in high-Tc superconductors, a research area that continues to develop at a remarkable pace. There have been numerous specialist conferences on high-Tc superconductors since their discovery by Bednorz and Muller in 1986. The Kirchberg meetings are intended as a school where experienced scientists from universities, research laboratories, and industry have the opportunity to discuss their most recent results, and where young scientists and students can learn about the present status of research in this field. The 1990 winter school was again organized in cooperation with the "Bundesministerium fur Wissenschaft in Austria and with the "Bundesministerium fur Forschung und Forschung" und Technologie" in the Federal Republic of Germany. The scientific interest was focused on the electronic structure of high-Tc superconductors and related compounds. At the beginning of each session, tutorial contributions were presented as an introduction for non-specialists. These were followed by research contributions elucidating the current state of our know ledge about high-Tc superconductors.

This volume contains extended abstracts of the 10 plenary lectures, 27 invited symposium lectures and ap- proximately 300 contributed papers that were presented at the 25th Congress Ampere. The contributions cover the full range of magnetic resonance and radiospectroscopy and their applications in physics, chemical physics, medicine and biology. Advanced NMR and ESR techniques are treated, as are their applications to novel materials.