Boron Chemistry – A Rapidly Expanding Research Field

Abstract

Guest Editors Vladimir Bregadze and Zuowei Xie give a short introduction to the field and history of boron chemistry. This thematic issue is devoted to boron chemistry. This field of chemistry quickly started to develop when scientists tried to investigate boron hydrides in the middle of the 20th century after Alfred Stock's discovery. At that time, the leading world countries started to invest a lot of money in research into this field, in view of the good prospects for the application of boron hydrides as rocket fuel. However the toxicity and flammability of these compounds prevented the investigations in this field. So, attempts were directed to synthesize less explosive and less toxic boron hydride derivatives. It was found that polyhedral boron hydrides are less toxic and not flammable. The first polyhedral boron hydrides were described in 1959 and 1960 by Hawthorne and Pitochelli1 with the examples of decahydro-closo-decaborate [B10H10]2– and dodecahydro-closo-dodecaborate [B12H12]2–. In these clusters, the whole polyhedron consist of boron atoms. At the end of 1963 the first communications describing the synthesis of icosahedral carboranes, a new unusual class of polyhedral compounds whose cage consisted of ten boron atoms and two carbon atoms,2, 3 were simultaneously published in USSR and USA. Although papers on derivatives known as lower and medium carboranes had already been published,4 the publications on higher icosahedral carboranes made a great impression on the scientific community of that time. It became clear that a new, important page in the development of chemistry was thus opened. The subsequent vigorous development of this field demonstrated that the discovery of carboranes is as significant as the discovery of metallocenes and fullerenes for the development of modern chemistry or even science as a whole. The boron hydrides and polyhedral boron compounds proved to be interesting from both practical and theoretical points of view. The studies of their structure and reactivity formed the basis for important chemical concepts such as three-center two-electron bonds, multicenter bonds, and three-dimensional aromaticity. The unusual structures and properties of polyhedral borates and carboranes, and metallaboranes and metallacarboranes derived from them, caught the attention of scientists to this field and led to the preparation of a great number of new compounds. A comprehensive monograph on carboranes was recently presented by Grimes.5 In addition to boranes and carboranes, other types of boron compounds also received an enormous amount of attention. As shown in this thematic issue, a total of 41 articles highlight the different aspects of current boron chemistry and encompass a broad spectrum of compounds bearing one to ten boron atoms. This field continues to remain important and popular as can be seen by the contributions from all over the world. We hope that readers will find this timely cluster issue interesting and stimulating. We wish to thank all contributors, reviewers, and the EurJIC editorial team for their high-quality and professional work. Vladimir Bregadze graduated from the Chemistry Department of M.V. Lomonosov Moscow State University in 1960. He received his Ph.D. and D.Sc. degree, Professor of Chemistry in USSR Academy of Sciences. He is now Head of Laboratory of Organoaluminum and Boron Compounds of the A.N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences. In 1976 V.I.Bregadze received the USSR State Prize for the Development and Application of New Materials in Industry, and in 1996 he received the Russian Federation State Prize in Science and Technology for the “Chemistry of Carboranes and Polyhedral Boranes”. His fields of interest are organic and inorganic derivatives of boron and main group metals, the chemistry of polyhedral boranes and carboranes, the study of their reactivity and application in medicine (antitumour activity, boron neutron capture therapy) and for the design of materials. He is Adjunct Professor of the Beijing University of Chemical Technology. He has published over 400 research papers, reviews and chapters in books. Zuowei Xie obtained a B.Sc. from Hangzhou University in 1983, a M.Sc. from Shanghai Institute of Organic Chemistry (SIOC), the Chinese Academy of Sciences in 1986, and his Ph.D. in 1990, working in a joint program between SIOC and Technische Universität Berlin. After serving as a Research Associate in SIOC and a Postdoctoral Fellow at University of Southern California, he joined the chemistry faculty of The Chinese University of Hong Kong in 1995, where he is now a Choh-Ming Li Professor of Chemistry. He has co-authored over 270 papers and received several prestigious awards including the State Natural Science Prize in 2008 and the Chinese Chemical Society Yao-Zeng Huang Award in Organometallic Chemistry in 2010.