Metal-Stabilized Thiyl Radicals Design Inspired by Elemental Periodic Extension Notion for Ligand-Based Alkene Addition.

Abstract

Inspired by alkene addition to the Ru and Re tris(thiolate) complexes via carbon-sulfur bond formation/cleavage reactions along with a periodic extension catalysis notion, a comparative study of the electronic structures, mechanisms, and reactivities for ethylene addition to the Os and Tc tris(thiolate) complexes was performed by DFT and high-level ab initio quantum calculations. The oxidized Os and Tc complexes were revealed to exhibit sufficient radical characters on the ligands to support their reaction with ethylene, whereas neutral Tc tris(thiolate) complex featuring little thiyl radical character renders no reactivity toward ethylene. Differential reactivities of these tris(thiolate) complexes was deemed to derive from the synergy of the thiyl radical character, the electronegativity, the row, and the charge. Extending from Ru and Re tris(thiolate) complexes to their Os and Tc counterparts can help us to get insightful rationales that would promote further research on alkene addition to metal-stabilized thiyl radicals.