Topics in Current Chemistry 358 Pierangelo Metrangolo Giuseppe Resnati Editors Halogen Bonding I Impact on Materials Chemistry and Life Sciences 358 Topics in Current Chemistry Editorial Board: H. Bayley, Oxford, UK K.N. Houk, Los Angeles, CA, USA G. Hughes, CA, USA C.A. Hunter, Sheffield, UK K. Ishihara, Chikusa, Japan M.J. Krische, Austin, TX, USA J.-M. Lehn, Strasbourg Cedex, France R. Luque, Cordoba, Spain M. Olivucci, Siena, Italy J.S. Siegel, Nankai District, China J. Thiem, Hamburg, Germany M. Venturi, Bologna, Italy C.-H. Wong, Taipei, Taiwan H.N.C. Wong, Shatin, Hong Kong [email protected] Aims and Scope The series Topics in Current Chemistry presents critical reviews of the present and future trends in modern chemical research. The scope of coverage includes all areas of chemical science including the interfaces with related disciplines such as biology, medicine and materials science. The goal of each thematic volume is to give the non-specialist reader, whether at the university or in industry, a comprehensive overview of an area where new insights are emerging that are of interest to larger scientific audience. Thus each review within the volume critically surveys one aspect of that topic and places it within the context of the volume as a whole. The most significant developments of the last 5 to 10 years should be presented. A description of the laboratory procedures involved is often useful to the reader. The coverage should not be exhaustive in data, but should rather be conceptual, concentrating on the methodological thinking that will allow the non-specialist reader to understand the information presented. Discussion of possible future research directions in the area is welcome. Review articles for the individual volumes are invited by the volume editors. Readership: research chemists at universities or in industry, graduate students. More information about this series at http://www.springer.com/series/128 [email protected] Pierangelo Metrangolo • Giuseppe Resnati Editors Halogen Bonding I Impact on Materials Chemistry and Life Sciences With contributions by C.B. Aakeroy€ Á D.L. Bryce Á G. Cavallo Á T. Clark Á W. Herrebout Á J.G. Hill Á P.S. Ho Á A.V. Jentzsch Á A.C. Legon Á S. Matile Á P. Metrangolo Á J.S. Murray Á T. Pilati Á P. Politzer Á G. Resnati Á C.L. Spartz Á G. Terraneo Á D.P. Tew Á J. Viger-Gravel Á N.R. Walker [email protected] Editors Pierangelo Metrangolo Giuseppe Resnati Laboratory of Nanostructured Laboratory of Nanostructured Fluorinated Fluorinated Materials (NFMLab) Materials (NFMLab) Department of Chemistry, Materials, Department of Chemistry, Materials, and and Chemical Engineering “Giulio Natta” Chemical Engineering “Giulio Natta” Politecnico di Milano Politecnico di Milano Milano, Italy Milano, Italy ISSN 0340-1022 ISSN 1436-5049 (electronic) Topics in Current Chemistry ISBN 978-3-319-14056-8 ISBN 978-3-319-14057-5 (eBook) DOI 10.1007/978-3-319-14057-5 Library of Congress Control Number: 2015933504 Springer Cham Heidelberg New York Dordrecht London © Springer International Publishing Switzerland 2015 This work is subject to copyright. All rights are reserved by the Publisher, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilms or in any other physical way, and transmission or information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed. The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. The publisher, the authors and the editors are safe to assume that the advice and information in this book are believed to be true and accurate at the date of publication. Neither the publisher nor the authors or the editors give a warranty, express or implied, with respect to the material contained herein or for any errors or omissions that may have been made. Printed on acid-free paper Springer International Publishing AG Switzerland is part of Springer Science+Business Media (www.springer.com) [email protected] Preface Typically, halogen atoms in haloorganics are considered as sites of high electron density because of their high electronegativity. Consistent with this well- established understanding, it is commonly accepted that halogen atoms can form attractive interactions by functioning as an electron-donor site (nucleophilic site). In fact, halogen atoms can work as hydrogen-bond acceptors and some cases of these interactions were recognized as early as the 1920s [1–4]. Halogen atoms of halocarbons also function as an electron-donor site when interacting with other elements, e.g., when entering the first coordination sphere of alkali metal cations1 or alkaline earth metal cations. However, the electron density in covalently bound halogens is anisotropically distributed [5–7]. There is a region of higher electron density, which forms a negative belt orthogonal to the covalent bond involving the halogen atom, and a region of lower electron density, which generates a cap on the elongation of the covalent bond (the so-called σ-hole) where the electrostatic potential is frequently positive (mainly in the heavier halogens). (This description of the distribution of the electron density holds for halogen atoms forming one covalent bond. For a discus- sion of polyvalent halogens see [8, 9].) This region can form attractive interactions with electron-rich sites but the general ability of halogen atoms to function as the electron acceptor site (electrophilic site) in attractive interactions has been fully recognized only recently. In 2009 the International Union of Pure and Applied Chemistry (IUPAC) started a project aiming “to take a comprehensive look at intermolecular interactions involving halogens as electrophilic species and classify them” [10]. An IUPAC Recommendation defining these interactions as halogen bonds [11] was delivered in 2013 when the project was concluded: This definition 1 A CSD search (CSD version 5.34, November 2012 plus one update, ConQuest version 1.15) for Y∙∙∙X-C short contacts (Y¼Li+,Na+,K+,Rb+,Cs+ and X¼Cl, Br, I) gave 140 hits and 296 counts, and revealed that the median value of the Y∙∙∙X-C angle is 103.08 (only structures with Y∙∙∙C > 3.0 Å were considered). Cations enter the most negative region of the halogen atom (i.e., the belt orthogonal to the X–C bond), thus confirming that the halogen atom is working as the nucleophile. v [email protected] vi Preface states that “A halogen bond occurs when there is evidence of a net attractive interaction between an electrophilic region associated with a halogen atom in a molecular entity and a nucleophilic region in another, or the same, molecular entity.” The IUPAC definition categorizes unambiguously an interaction responsi- ble for the formation of adducts described as early as 1814 but which had been overlooked for decades. It developed into a routinely used tool to direct self- assembly phenomena only after its effectiveness in crystal engineering was demonstrated in the mid-1990s [12]. The halogen bonding practice and concept has developed through a rather patchy course. As a consequence, it seems particularly timely to open this book with a brief history of the interaction, as a perspective of the topic may help the reader to understand better how the present situation has been reached. In the first chapter P. Metrangolo and G. Resnati examine how the halogen bonding concept emerged and became established in, and accepted by, a broad chemical community. The second chapter by P. Politzer et al. focuses on a physical interpretation of halogen bonding from a theoretical point of view. Studies on halogen-bonded complexes in the gas phase are highlighted in the third chapter by A. C. Legon and N. R. Walker, while cryogenic solutions containing halogen-bonded complexes are examined in the fourth chapter by W. Herrebout. C. B. Aakeroy€ and C. L. Spartz discuss the use of halogen bonding in supramolecular synthesis in the fifth chapter, and the study of such solid-state halogen-bonded complexes is described in the sixth chapter by D. L. Bryce and J. Viger-Gravel. A. V. Jentzsch and S. Matile discuss how to use halogen bonds in anion recognition and transport in the seventh chapter, while the last chapter by P. S. Ho closes the first volume of this book with a survey of biomolecular halogen bonds. This first volume of the book “Halogen Bonding: Impact on Materials Chemistry and Life Sciences” opens with a historical perspective and a basic understanding of the halogen bond and closes showing the impact that this interaction is having in various fields such as crystal engineering, supramolecular synthesis, and medicinal chemistry. Many other fields benefit from the use of halogen bonding and will be treated in the second volume of the book. Milan, Italy Pierangelo Metrangolo Giuseppe Resnati References 1. Hantzsch A (1915) Die Chromoisomerie der p-dioxy-terephthalsa¨ure derivate als phenol- enol-isomerie. Chem Ber 48:797–816 2. Nakamoto K, Margoshes M, Rundle RE (1955) Stretching frequencies as a function of distances in hydrogen bonds. J Am Chem Soc 77:6480–6486 3. Schleyer PR, West R (1959) Comparison of covalently bonded electro-negative atoms as proton acceptor groups in hydrogen bonding. J Am Chem Soc 81:3164–3165 [email protected] Preface vii 4. Metrangolo P, Resnati G (2013) Metal-bound halogen atoms in crystal engineering. Chem Commun 49:1783À1785 5. Metrangolo P, Resnati G (eds) (2008) Halogen bonding: fundamentals and applications.