Polyphosphorus Ligand Complexes of Coinage Metals for Multiple Capturing of Intact P$_4$ Tetrahedra

Two- and three-component self-assembly reactions of [CpRFe(η5-P5)] (CpR = C5(CH3)5 (Cp*, 1a), C5(4-EtC6H4)5)(CpPEt, 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 CpR 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 CpR 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.