From a political, societal and scientific point of view, it is imperative to counteract global warming and overcome energy scarcity. From a scientific perspective, nanostructured materials play a crucial role in achieving these goals, e.g. in the development of energy-saving light-emitting diodes, solar cells, rechargeable batteries or gas storage technologies. However, the potential design of the structure-related properties of such nanostructured compounds requires in-depth knowledge and strict control of their crystallization processes, which can be achieved by monitoring the corresponding chemical reactions in situ. This book is aimed at undergraduate and graduate students who wish to gain an overview of the applications, synthesis, or in situ characterization of inorganic nanostructured compounds such as lanthanide-based materials, quantum dots, magnetic nanoparticles, bioceramics, battery electrodes, and metal-organic frameworks.