Unsurprisingly, given their anionic nature, ACDAs are prone to binding cationic guests, although encapsulation of neutral molecules including halocarbons and P4 and As4 70 has been demonstrated. As with coordination cages, guest molecules (or lack thereof) can template the formation of different topologies. [(PO4)4116] 12-, for example, formed in the presence of a tetramethylammonium guest; with tetrabutylammonium as the countercation, however, which was too large to fit within the cavity of the tetrahedron, an A2L3 helicate was formed. In contrast, tetrahedral cage [(PO4)4144] 12-was found to form with or without a suitably sized cationic template, and exhibited conformational flexibility to the encapsulation of different sized ammonium cations. ACDAs are generally assembled, soluble, and stable in high polarity solvents such as acetonitrile, DMF and DMSO. As such, they can be characterised in solution using standard NMR, DOSY and MS techniques, as well as in the solid-state using SCXRD.