The magnificent bouquet of porphyrinoids is a family of macrocyclic compounds bearing similar structures as the parent molecule porphyrin. Typically, their structures can be further modified with various functional groups at the periphery and the core. Porphyrinoids are of interest for many applications such as photosynthesis, catalysis, electrochemistry, chemical sensors, photodynamic therapy, material sciences, and waste water treatment, as well as colorants. Hence, the chapters of this book intend to cover present and future trends in the research field of artificial porphyrinoids dealing with, for example, straightforward synthetic strategies, chemical and physical properties, theory, structural modifications at the periphery and core, ring contraction and expansion, perturb electronic structures, and aromaticity of porphyrinoids. The relationship between the structure and spectroscopic properties of this family of compounds also will be discussed.

We hope that this book with contributions from world-wide leading scientists will be a benefit not only for students but also for researchers who are active in chemistry, physics, material sciences, mechanical and electrical engineering, and medicine.

We would like to thank very warmly all of the authors who contributed to this book in an outstanding manner. We have had a lot of fun working together with them as a team. It was just marvelous. Excellent fruitful discussions resulted in significant improvement of the book in general.

Our thanks also go to Robin Driscoll, Katie Morray, Connor Sheppard, and Lewis Pearce at the Royal Society of Chemistry for their enthusiastic, devoted help in setting up this book project and assisting during the editorial process. For us, it was a great and excellent experience working with you.

Last but not least we would like to address our thanks to Hans-Jörg Schneider for inviting and convincing us to edit this book.

We wish all readers that this book will be beneficial and a very valid guide through the topic of porphyrinoids in any aspect, but also guiding and convincing students that the field of porphyrinoids is fascinating, charming, and hence just great. Enjoy reading it!

Heinrich Lang

Tobias Rüffer