Promoting exchange coupling in (Cp^iPr)₂Gd₂X₃ complexes

Introducing magnetic coupling between lanthanide ions has been shown to yield better-performing single-molecule magnets (SMMs), as exemplified by the Cp₂^iPrLn₂I₃ family of compounds (Cp^iPr: pentaisopropylcyclopentadienyl, Ln: Gd, Tb, or Dy). This unique coupling is mediated through an unpaired electron hosted in a σ-like orbital, that results from the two 5d Ln ions, and understanding these interactions holds the key to continue advancing the rational design of SMMs. Here, we focus on the Cp₂^iPrGd₂I₃ spin-only system and apply a recently proposed DFT-based decomposition scheme to assess the chemical and structural factors that affect the magnetic coupling. Based on these, we propose synthetically feasible systems with increased coupling.