Antimony ligand helps turn on platinum reactive site

Abstract

Homogeneous transition-metal complexes typically need a jump start to become catalytically active. One strategy chemists employ is to use a silver salt or a Lewis acid activator such as a boron compound to pull off and sequester an anionic ligand from the catalyst metal. Di You and Francois P. Gabbai of Texas A&M University have designed a new strategy for ligand abstraction by building an antimony Lewis acidic site directly into a platinum catalyst’s architecture, forming a self-activating catalyst system (J. Am. Chem. Soc. 2017, DOI: 10.1021/jacs.7b03287). Gabbai’s group is known for synthesizing electron-deficient main-group compounds and studying their anion-binding and redox properties. While investigating antimony-platinum complexes, the researchers found that antimony’s ability to adopt variable coordination numbers, a property the Gabbai group calls coordination noninnocence, enables antimony to shed loosely bound anionic ligands such as triflate and add stronger coordinating anions such as chlori...