Crystal-packing motifs of [Ag4L4]4+ star-burst tetrahedra

Abstract

Further examples of a metallo-supramolecular ‘star-burst’ tetrahedron are reported from reaction of the ligand tris(4-pyridylmethylamino)cyclotriguaiacylene, 1, and AgPF₆ in the presence of dinitrile species, or from reaction of 1 with Ag[1-Ph-closo-1-CB₉H₈-6-I]. Complex [Ag₄(1)₄(CH₃CN)₃]·4(PF₆)·5(CH₃CN)·(H₂O) has a hexagonal structure where packing of the [Ag₄(1)₄]⁴⁺ tetrahedra mimics the close-packing of spheres. In complex {Ag₄(1)₄(CH₃CN)₂[PhCB₉H₈I]₂}·2[PhCB₉H₈I]·11(CH₃CN) the [1-Ph-closo-1-CB₉H₈-6-I]⁻ anion coordinates to the [Ag₄(1)₄]⁴⁺ tetrahedron through Ag–I and Ag⋯H–B interactions, and a less symmetric packing motif is found. The synthesis and crystal structure of the novel monocarbaborane species (NEt₄)[1-Ph-closo-1-CB₉H₈-6-I] are also reported.