X-Ray Diffraction of Ions in Aqueous Solutions: Hydration and Complex Formation

The idea of writing a book about the structural investigations of ionic solutions by X-ray diffraction (XRD) wandered in the authors' minds for a long time. In fact, while research activities in this field have largely increased in the last 15 years, utilizing well-established diffractometric techniques, a complete review of the up to date results has been never attempted. More recently, the authors became aware, as it is better explained in the Foreword, of the presence of some confusion in the literature whenever results on the structure of solutions were mentioned. For these reasons, and thanks to the interest of CRC Press the authors came to the decision of examining all the material presently available, with the aim to present to the interested reader an exhaustive and reasoned selection of it. In this perspective, the authors felt that their work had to include, beside the rational classification of the results, also a comprehensive treatment of the theoretical principles of the X-ray diffraction approach as used when dealing with nonordered systems, as well as a detailed description of experimental and interpretative methods. Therefore, this book should be useful not only to scholars interested in results, but also to students approaching the field of nonordered systems. To them, the authors hope to convey the right feeling about the reliability of XRD information.

It is now widely accepted by chemists, biochemists, and physicists that ion-water inter actions are responsible for the routes of many chemical and biochemical processes; it has also become evident, from the numerous studies on ionic hydration, that any further progress in this field is strongly dependent on a satisfactory structural description of solutions. To this end, the general methods used in the study of any liquid or amorphous system can be applied.