Self-assembly of a "cationic-cage" via the formation of Ag-carbene bonds followed by imine condensation

A new strategy for the synthesis of a "cationic-cage" (CC-Ag) has been developed via metal-carbene (M-CNHC) bond formation followed by imine bond condensation. Reaction of a trigonal trisimidazolium salt H3L(PF6)3 functionalized with three flexible N-phenyl-aldehyde pendants with silver oxide yielded a trinuclear tricationic organometallic cage (OC-Ag). Subsequent treatment of the organometallic cage (OC-Ag) with 1,4-diaminobutane links the two tris-NHC ligands via imine bond condensation, which thus generates a 3D 'cationic-cage' (CC-Ag). Furthermore, post-synthetic replacement of the Ag(i) with Au(i) leading to the formation of CC-Au was achieved via trans-metalation, with the retention of the molecular architecture.