Monomeric Chini-Type Triplatinum Clusters Featuring Dianionic and Radical-Anionic π*-Systems.

Owing to their unique topologies and abilities to self-assemble into a variety of extended and aggregated structures, the binary platinum carbonyl clusters [Pt₃(CO)₆] _n²⁻ ('Chini clusters') continue to draw significant interest. Herein, we report the isolation and structural characterization of the trinuclear electron-transfer series [Pt₃(μ-CO)₃(CNAr^Dipp2)₃] ⁿ⁻ ( n=0, 1, 2), which represents a unique set of monomeric Pt₃ clusters supported by π-acidic ligands. Spectroscopic, computational, and synthetic investigations demonstrate that the highest-occupied molecular orbitals of the mono- and dianionic clusters consist of a combined π*-framework of the CO and CNAr^Dipp2 ligands, with negligible Pt character. Accordingly, this study provides precedent for an ensemble of carbonyl and isocyanide ligands to function in a redox non-innocent manner. [ABSTRACT FROM AUTHOR]