TRIPODAL LIGANDS AS POWERFUL PLATFORMS FOR DESIGNING NEW CATALYSTS

Abstract

Tripodal ligands serve as excellent ancillary ligands to synthesize various complexes and have been used in diverse areas such as catalysis, small-molecule activation, and bioinorganic chemistry. The trispyrazolylborate ligands are a well-known family of anionic tridentate and tripodal ligands, also the most popular class of “scorpionate ligands” however, several new types including tris(carbene)borate ligands have been prepared. There are two varieties of the tripodal ligands, tridentate and tetradentate, known which can coordinate to the central metal with local C3 symmetry. The simple tripodal ligands tune the electronic and steric properties of the metal complexes by modifying the donor atoms or substituents present on the ligand backbone. Ligands containing identical sets or combinations of the donor atoms viz. carbon, nitrogen, oxygen, phosphorous, or other main group elements are known. This chapter includes the historical aspects of tripodal ligands as well as recent developments in the chemistry of complexes with these ligands. Properties of the tripodal ligands are discussed for the structural aspects and their binding ability with the metal centres. Further, transition metal complexes with these ligands, their structure, properties, and applications in catalysis are discussed. © 2021 by Nova Science Publishers, Inc.