Pure and Applied Chemistry

This issue of Pure Appl. Chem. is devoted to papers based upon invited lectures delivered at the first IUPAC-sponsored Workshop on Advanced Material, "WAM1: Nanostructured Systems", held at the Hong Kong University for Science and Technology (HKUST) on July 14-18, 1999.

Why nanostructured material? Chemists contribute to the well-being of society by exploiting the properties of the elements of the periodic table, or various forms of combination of elements, to make materials that are useful for "better living through chemistry." What happens if we use all the possible combinations that can be made? There remain great demands for developing new materials to improve our lives in fields such as medicine, energy, improving the environment, communication and transportation. Thus, we have to think of new ways to make materials that can be expected to display properties appropriate to the technologies of the new Millennium!

The difference in properties of different elements and their derived compounds is a result of differences in the type of motion that their electrons can execute. This, in turn, depends on the space available for the electronic motion and the degree of its confinement. Thus, the difference between a metal, a semiconductor and an insulator is attributable to the electrons being delocalized in the first, more confined in the second and highly confined in the last. Can we physically cut material size sufficiently to change its electronic degree of confinement and thus its properties? We do know that while copper metal is a conductor, the copper atom and small molecular clusters of copper atoms are insulators. What is the size of an elemental assembly of a metal (i.e. the number of atoms in it) at which the metal-semiconductor or the metal-insulator transition occurs? Of course it depends on the length scale of the property measured. For semiconductors and metals, a large change in properties, e.g. absorption, emission, and conductivity, occurs on the nanometer length scale. Equally important, the property becomes very sensitive to the size of the nanoparticle. It can thus be expected that many variations in these properties should be observed for the same material by simply changing its size. The potential for harnessing these changes of properties in new technological applications is largely responsible for the current appeal of this exciting field. These considerations, along with our personal research interests, convinced me and Professor Joshua Jortner that it would be opportune to adopt this theme for the first IUPAC Workshop on Advanced Material.

The publication of the talks given at the Workshop is timely, given the extraordinary rapidity with which new developments are taking place in the field. This collection of papers complements other recent publications of reviews on the topic of nanostructures, since it is more in the nature of a symposium-in-print and offers an assembly of short overviews and research papers which capture the dynamic associated with research at interdisciplinary interfaces, and with the development of attendant synthetic and analytical techniques. The promise of unimagined properties of nanostructured materials and of new-generation applications is an ongoing stimulus for further research, and it is hoped that this publication will contribute to the process, and furnish practitioners with new insights and inspiration. This is truly a multidisciplinary and future-targeted area of scientific research, and one which fully meets the IUPAC vision of 'new directions in chemistry', with its promise of hitherto undefined vistas of opportunity for discovery and exploitation.

The Workshop

The quality of the scientific presentations at this meeting was very high indeed. The strong international representation is in keeping with the spirit of IUPAC as well as the global nature of scientific research. The idea of the meeting was to get scientists active in advanced material from the West to interact strongly with those from the Orient. In this regard, we have succeeded as we achieved representation from seven countries from each side [China (Mainland and Hong Kong), Japan, Korea, Philippines, Singapore, and Taiwan from the Orient, and Canada, France, Germany, Israel, Spain, United Kingdom, and USA from the West]. This great accomplishment of getting us all together in such a delightful atmosphere was the result of the wise sponsorship of IUPAC and the great efforts of many people, whom I would like to acknowledge below.

IUPAC: for its wisdom to sponsor workshops in frontier areas of chemical research. We thank the then-IUPAC President, Prof. Joshua Jortner for cochairing the Workshop. We also thank the IUPAC Secretariat, in particular its Executive Director, Dr. John Jost, for his continuous and prompt support and Dr. Fabienne Meyers for creating and editing our web page for the Workshop and for her essential assistance in the production of this special volume.

HKUST: for hosting us. We thank Dr. Nai-Teng Yu of the Chemistry Department, whose willingness to help us by accommodating the Workshop in his Department was essential; Dr. Shihe Yang whose continuous hard work and efforts made it possible to follow up the registration process; the local organizers, in particular, Prof. Leroy Chang and Ping Sheng, who supplied us with the list of participants, the names of some invited speakers and the program of a similar meeting held there recently and the Departmental staff, for their help in getting the arrangements of this workshop finalized.

Georgia Tech: Dr. Clemens Burda helped in getting the workshop abstracts and putting the workshop material together, Ms. Michele Papsidero, my own secretary, spent many hours of hard work in following the process, from completing the registration list, to reminding contributors to meet different deadlines including sending the abstracts, and finally in typing and collating the whole program for the Workshop. The assistance of the USA Organizing Committee and in particular, Profs. John Zhang and Rob Whetten at Georgia Tech, was extremely useful in finalizing the scientific program.

The speakers: I thank both the plenary and invited speakers who accepted our invitation, most without asking for financial support. Without them, we would not have had such an excellent scientific meeting or this valuable volume of Pure Appl. Chem.

I wish to thank Professor James Bull, the editor of this special issue, for his hard work in making sure he received the manuscripts in time, for the review process of these manuscripts and for putting the whole volume together.

Chairman, Organizing Committee

Julius Brown Professor School of Chemistry and Biochemistry Georgia Institute of Technology