Polyphosphorus Ligand Complexes of Coinage Metals for Multiple Capturing of Intact P₄ Tetrahedra

Two- and three-component self-assembly reactions of [Cp^RFe(η⁵-P₅)] (Cp^R = C₅(CH₃)₅ (Cp*, 1a), C₅(4-EtC₆H₄)₅) (Cp^PEt, 1b)) with the coinage metal salts [Cu(CH₃CN)₄][SbF₆] or AgSbF₆ were investigated to study the prerequisites for the potential coordination of white phosphorus by using a sterically encumbered Cp^R ligand and noncoordinating anions. In the self-assembly reactions with white phosphorus, either 0D or 1D coordination complexes are formed, all of which feature coordinated intact P₄ tetrahedra and thus comprise an unprecedented class of mixed polyphosphorus ligand complexes capable of complete release of P₄ in solution confirmed by NMR studies. The bulkiness of the used Cp^R ligand and the correctly chosen solvent allowed for obtaining more beneficial structural motifs, the first discrete tetra- and penta-coordinated cyclo-P₅ ligand complexes, that provide the maximal content of coordinated P₄ molecules per species known so far. All products are characterized by single-crystal X-ray diffraction, NMR spectroscopy, and mass spectrometry.