Small molecule activation by well-defined compounds of heavy p-block elements.

The creative design and exploration of new bonding motifs and molecular architectures in main group chemistry have pushed the boundaries of reactivity in this field of research. In this context, the activation of small molecules represents a set of benchmark reactions and offers valuable opportunities for the development of innovative synthetic methods. In addition to significant progress by use of transition metal complexes and compounds of lighter p-block elements, compounds based on heavy p-block elements (with the principle quantum number > 4) have seen major advances in recent years. Fundamental properties originating from their high atomic number (such as the size, energy, and polarizability of atomic orbitals) set them apart from more established species in small molecule activation. Challenges and opportunities arising from this scenario are analyzed and highlighted.