^a Precise location still to be confirmed.

This is the third and final book of three volumes of critical overviews of the key areas of ionic liquid chemistry. The first volume was entitled Ionic Liquids UnCOILed; the second was Ionic Liquids Further UnCOILed. The history and rationale behind this trilogy were explained in the preface to Volume 1 and so will not be repeated here. But we did instruct the authors as follows: ‘It is important to emphasise that these are meant to be critical reviews. We are not looking for comprehensive coverage, but insight, appreciation and prospect. We want the type of review which can be read to give a sense of importance and scope of the area, highlighting this by the best published work and looking for the direction in which the field is moving. We would also like the problems with the area highlighting, e.g. poor experimental technique, poor selection of liquids, and variability of data’. Looking back over all three books, we are amazed at the quality of reviews produced and their ‘timeless’ nature – they are fresh and inciteful.

This final book includes eleven critical expert overviews of differing aspects of ionic liquids – the final chapter could almost be a stand-alone book. It is our continuing view that, in the second decade of the twenty-first century, reviews that merely regurgitate a list of all papers on a topic, giving a few lines or a paragraph (often the abstract!) to each one, have had their day – 5 min with an online search engine will provide that information. But we are sure that the growth of open-access journals and books from predatory online publishers will guarantee their prolonged existence. Such reviews belong with cassette tapes, typewriters and the printed journal – valuable in their day, but of little value now. The value of a review lies in the expertise and insight of the reviewer and their willingness to share it with the reader. It takes moral courage to say ‘the work of […] is irreproducible, or of poor quality, or that the conclusions are not valid’ – but in a field expanding at the prestigious rate of ionic liquids, it is essential to have this honest feedback. Otherwise, errors are propagated. Papers still, in 2015, appear using hexafluorophosphate or tetrafluoroborate ionic liquids for synthetic or catalytic chemistry, and calculations on ‘ion pairs’ are still being used to rationalise liquid state properties! We trust this volume, containing eleven excellently perceptive reviews, will help guide and secure the future of ionic liquids. We believe the reviews in our volumes should be compulsory reading for all research workers in the field.

This volume is a collaborative effort. We, the editors, have our names emblazoned on the cover, but the book would not exist in its present form without the support from many people. Firstly, we thank our authors for producing such splendid, critical chapters and for their open responses to the reviewers’ comments and to editorial suggestions. We are also indebted to our team of expert reviewers, whose comments on the individual chapters were challenging and thought provoking, and to Martyn J. Earle for his photographic assistance. The backing from the team at Wiley, led by Dr. Arza Seidel, has been fully appreciated – it is always a pleasure to work with such a professional group of people. Finally, this book would never have been published without the unfailing, enthusiastic support from Deborah Poland and Sinead McCullough, whose patience and endurance continue to make the impossible happen. So we thank again everyone involved in the project – we are proud to have been associated with them.

ANDREW P. ABBOTT, Chemistry Department, University of Leicester, Leicester, UK

JÜRGEN ARNING, Department 10: Theoretical Ecology, UFT-Centre for Environmental Research and Sustainable Technology, University of Bremen, Bremen, Germany

STEVEN BALDELLI, Department of Chemistry, University of Houston, Houston, Texas, USA

PAUL M. BAYLEY, Institute for Frontier Materials, Geelong Technology Precinct, Deakin University, Victoria, Australia

JOSÉ N. CANONGIA LOPES, Centro de Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa, Lisboa, Portugal and Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Oeiras, Portugal

MARGARIDA COSTA GOMES, Institut de Chimie de Clermont-Ferrand, Université Blaise Pascal and CNRS, Aubière, France

PHILIPP EIDEN, Department for Inorganic and Analytic Chemistry, Freiburger Materialforschungszentrum (FMF) and Freiburg Institute of Advanced Studies (FRIAS: Soft Matter Science), Albert-Ludwigs-Universität Freiburg, Freiburg, Germany

MARIA FORSYTH, Institute for Frontier Materials, Geelong Technology Precinct, Deakin University, Victoria, Australia

HIRO-O HAMAGUCHI, Institute of Molecular Science and Department of Applied Chemistry, National Chiao Tung University, Hsinchu, Taiwan, and Department of Chemistry, School of Science, The University of Tokyo, Tokyo, Japan

CHRISTOPHER HARDACRE, School of Chemistry and Chemical Engineering, Queen’s University of Belfast, Belfast, UK

MARCO HAUMANN, Lehrstuhl für Chemische Reaktionstechnik, Universität Erlangen-Nürnberg, Erlangen, Germany

TAKASHI HIROI, Department of Chemistry, School of Science, The University of Tokyo, Tokyo, Japan

KOICHI IWATA, Department of Chemistry, Gakushuin University, Tokyo, Japan

INGO KROSSING, Department for Inorganic and Analytic Chemistry, Freiburger Materialforschungszentrum (FMF) and Freiburg Institute of Advanced Studies (FRIAS: Soft Matter Science), Albert-Ludwigs-Universität Freiburg, Freiburg, Germany

PETER LICENCE, School of Chemistry, University of Nottingham, Nottingham, UK

MARIANNE MATZKE, NERC Centre for Ecology & Hydrology Molecular Ecotoxicology, Acremann Section Maclean Building, Benson Lane Crowmarsh Gifford, Wallingford Oxfordshire, UK

CAROLIN MEYER, Lehrstuhl für Chemische Reaktionstechnik, Universität Erlangen-Nürnberg, Erlangen, Germany

CLAIRE MULLAN, School of Chemistry and Chemical Engineering, Queen’s University of Belfast, Belfast, UK

JAN NOVAK, Institute for Frontier Materials, Geelong Technology Precinct, Deakin University, Victoria, Australia

AGILÍO A. H. PÁDUA, Institut de Chimie de Clermont-Ferrand, Université Blaise Pascal and CNRS, Aubière, France

CHARIZ PEÑALBER-JOHNSTONE, Department of Chemistry, University of Houston, Houston, Texas, USA

KARL RYDER, Chemistry Department, University of Leicester, Leicester, UK

SATYEN SAHA, Department of Chemistry, Banaras Hindu University, Varanasi, India

STEFAN STOLTE, Department 3: Sustainability in Chemistry, UFT-Centre for Environmental Research and Sustainable Technology, University of Bremen, Bremen, Germany

ALASDAIR W. TAYLOR, School of Chemistry, University of Nottingham, Nottingham, UK

PETER WASSERSCHEID, Lehrstuhl für Chemische Reaktionstechnik, Universität Erlangen-Nürnberg, Erlangen, Germany

TOM WELTON, Department of Chemistry, Imperial College London, London, UK

SEBASTIAN WERNER, Lehrstuhl für Chemische Reaktionstechnik, Universität Erlangen-Nürnberg, Erlangen, Germany

NEIL WINTERTON, Department of Chemistry, University of Liverpool, Liverpool, UK

TRISTAN G. A. YOUNGS, ISIS Facility, Rutherford Appleton Laboratory, Chilton, UK