Dicationic Tetrylene Ligands Modulate Pt 0 π‐Acid Catalysis

ABSTRACT Dicationic heavy tetrylenes [E] 2+ (Ge, Sn, Pb) represent a rare class of ambiphilic yet electron‐withdrawing species. However, their broader exploration has been hampered by intrinsic instability, donor quenching, and weak affinity to metals. Here, we overcome these limitations by utilizing neutral double‐decker bis(phosphinophenylimino)pyridine ligand 1 to anchor Pt 0 and [E] 2+ in a one‐pot synthesis, forming a series of heterobimetallic [ 2E ] 2+ . [E] 2+ as Z‐type ligands results in polarized Pt 0 →E II interaction, which leads to the rare square‐planar geometries for Pt 0 centers and consequently π‐acid catalysis on a Pt 0 center. [ 2E ] 2+ is ambiphilic, binding isocyanides at Pt and [M(CO) 5 ] fragments at the tetrel center (E = Sn, M = Cr, Mo, W), respectively. Using ν CN of isocyanide adducts as an IR probe, we benchmark the σ‐acceptor strength of [E] 2+ across the platform for the first time (Ge 2+ > Sn 2+ > Pb 2+ ). This trend translates directly into Pt 0 ‐catalyzed 1,6‐enyne cycloisomerization, enabling up to ∼1000‐fold rate tuning via (i) element identity (Ge, Sn, Pb) and (ii) Lewis‐acid binding at E (e.g., [M(CO) 5 ]; M = Cr, Mo, W). These results establish a coarse‐to‐fine tuning strategy for Pt 0 π‐acidity using a modular and electronically adjustable [E] 2+ ligand platform.