Synthetic access to low-coordinate Pb mono- and dications is in general impeded due to their poor solubility and highly electrophilic nature. However, the electrophilicity of these cations can be tamed by attaching them to electron-rich transition metals. Following this principle we have isolated low-valent Pb mono- ([(Cy3P)2Pt–PbCl]2[AlCl4]2, >8a) and dications ([(Cy3P)2Pt(Pb)][AlCl4]2, >11) in the coordination sphere of platinum. The same approach then has been implemented for the isolation of analogous low-valent Sn mono- (>7a) and dications (>10). An energy decomposition analysis (EDA-NOCV) was performed to investigate the nature of Pt–Pb and Pb–Cl bonding in [(Cy3P)2Pt(PbCl2)] (>2), >8a and >11. The results show that the Pt–Pb bonds in >8a and >11 are electron-sharing in nature, whereas that of the precursor >2 is a dative bond. The breakdown of attractive interactions in >2, >8a and >11 reveals that the ionic interactions in the analyzed Pt–Pb and Pb–Cl bonds are always stronger than the covalent interactions, except for the Pb–Cl bond in >8a. The calculated D3 dispersion energies show that dispersion interactions play a key role in the thermodynamic stability of >2, >8a and >11.
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