Based on a translated Japanese title published in 2012, this book provides fundamental aspects of experimental and computational methods, the properties and structure of solvents, ion solvation and equilibria and reactions of metal complexes in solution. It includes state-of-the-art details on metal complexes in newly developing sustainable liquids and applications in real life. Appealing to researchers working in coordination chemistry, including students and industrialists, the text uses exercises, tables and figures to help the reader with their understanding of the topic.