Reduction of the Host Cationic Framework Charge by Isoelectronic Substitution: Synthesis and Structure of Hg₇Ag₂P₈X₆ (X = Br, I) and Hg₆Ag₄P₈Br₆

The first compounds, Hg7Ag2P8X6 (X = Br, I) and Hg6Ag4P8Br6, featuring the partial isoelectronic substitution of Hg2+ for Ag1+ in mercury−pnicogen frameworks have been obtained and structurally characterized. The new compounds are the supramolecular assemblies built of the covalently bonded metal−pnicogen frameworks trapping guests of different complexity. The frameworks feature the perfect ordering of Hg2+ and Ag1+ cations and contain P24- and P66- phosphorus clusters. The substitution of Hg2+ with Ag1+ leads to the reduction in charge of the host cluster-containing cationic matrix and concomitant replacement of the monatomic X- guest by a lesser amount of the AgBr32- anions.