Supramolecular squares with Rh24+ corners

Abstract

Six molecular squares were obtained by reacting the singly metal–metal-bonded complex [Rh₂(cis-DAniF)₂(CH₃CN_eq)₄(CH₃CN_ax)₂](BF₄)₂ (DAniF = N,N′-di-p-anisylformamidinate), and (Et₄N⁺)₂(Carb²⁻) where Carb²⁻ represents the dicarboxylate anion bicyclo[1.1.1]pentane-1,3-dicarboxylate, 1; tetrafluoroterephthalate, 2; 1,4-cubanedicarboxylate, 3; terephthalate, 4; fumarate, 5; trans-1,4-cyclohexanedicarboxylate, 6; these squares stack in the crystal forming square channels capable of accommodating solvent molecules and the NMR spectra are consistent with the presence of highly symmetrical structures even in solution.