**Preface**

This reprint focuses on the geometrical and spectroscopic features as well as the potential applications of halogen, chalcogen, pnictogen, tetrel, and triel bonds in chemical reactions, crystal engineering, molecular recognition, and biological systems. We aim to present cutting-edge studies concerning the bonds formed between some novel and important electron donors and acceptors, similarities and differences between these bonds, structures of the complexes composed of these bonds in the solution and gas phases, spectroscopic methods for measuring these bonds in solution and gas phases, and applications of these bonds in chemical reactions, crystal engineering, molecular recognition, and biological systems.

**Qingzhong Li, Steve Scheiner, and Zhiwu Yu**

*Editors*
