Pd 8 (PDip) 6 : Cubic, Unsaturated, Zerovalent

• Published in: Advanced science 2024-07, Vol.11 (25), p.e2400699
• Main Authors: Breitwieser, Kevin, Bevilacqua, Matteo, Mullassery, Sneha, Dankert, Fabian, Morgenstern, Bernd, Grandthyll, Samuel, Müller, Frank, Biffis, Andrea, Hering-Junghans, Christian, Munz, Dominik
• Format: Article
• Language: English
• ISSN: 2198-3844; 2198-3844
• DOI: 10.1002/advs.202400699

Atomically precise nanoclusters hold promise for supramolecular assembly and (opto)electronic- as well as magnetic materials. Herein, this work reports that treating palladium(0) precursors with a triphosphirane affords strongly colored Pd (PDip) that is fully characterized by mass spectrometry, heteronuclear and Cross-Polarization Magic-Angle Spinning (CP-MAS) NMR-, infrared (IR), UV-vis, and X-ray photoelectron (XP) spectroscopies, single-crystal X-Ray diffraction (sc-XRD), mass spectrometry, and cyclovoltammetry (CV). This coordinatively unsaturated 104-electron Pd(0) cluster features a cubic Pd -core, µ -capping phosphinidene ligands, and is air-stable. Quantum chemical calculations provide insight to the cluster's electronic structure and suggest 5s/4d orbital mixing as well as minor Pd─P covalency. Trapping experiments reveal that cluster growth proceeds via insertion of Pd(0) into the triphosphirane. The unsaturated cluster senses ethylene and binds isocyanides, which triggers the rearrangement to a tetrahedral structure with a reduced frontier orbital energy gap. These experiments demonstrate facile cluster manipulation and highlight non-destructive cluster rearrangement as is required for supramolecular assembly.