Modern organometallic multidentate ligand design strategies: The birth of the privileged “pincer” ligand platform

The seemingly simple tridentate ligand design, one that is now known as the “pincer,” has gained increasing importance in metal–ligand chemistry and in other applications as diverse as organic synthesis, catalysis, and materials science. This chapter describes the historical context in which the pincer ligand platform developed and sketches how Shaw’s research played a crucial early role. The original chemistry, emerging in the late 1970s and early 1980s, is presented which details the synthesis and properties of the first examples of pincer-based organometallic complexes along with a selection of related species. Finally, a connection is made from this early start to the excellent and striving studies that currently are ongoing in pincer chemistry and its applications thereof.