A trefoil-shaped macrocycle with [12]-imidazolium cations

A trefoil-like two-dimensional (2D) C_3v symmetric organic 12]-imidazolium cation H₁₂–2(PF₆)₁₂ featuring three 4]-imidazolium macrocycles was synthesized in three steps. The reaction of a dodecakis H₁₂–1(PF₆)₁₂ imidazolium salt with Ag₂O resulted in the formation of a hexanuclear Ag^I dodecacarbene assembly Ag₆(1)](PF₆)₆. Upon UV irradiation, the photodimerization of the cinnamic ester pendants of Ag₆(1)](PF₆)₆ led to the generation of a trefoil-like complex Ag₆(2)](PF₆)₆ containing three closed metallacycles. Removal of metal ions allowed for the synthesis of the target molecule. All complexes were fully characterized by NMR spectroscopy (¹H, ¹³C{¹H} and 2D NMR) and high-resolution electrospray ionization mass spectrometry (HR-ESI-MS).