Silver-Dabco Coordination Networks with Distinct Carbaborane Anions: Investigating Ag•••H-B and Ag•••I-B Interactions

A novel series of metal-organic frameworks (MOFs) based on Ag(I) and the nitrogen-bridging ligand 1,4-diazabicyclo[2.2.2]octane (dabco) along with the incorporation of distinct carbaborane anions were synthesized and isolated as crystalline materials. Single-crystal X-ray diffraction analysis unveiled novel materials formulated as [Ag(dabco)]-[Cobdc] (1), [Ag(dabco)(PhCB9H9)] (2), [Ag(dabco)-(PhCB9H8I)] (3), and [Ag(dabco)(PhCB11H5I6)] (4), which were further characterized by Fourier-transform infrared spectroscopy and elemental analysis. Interestingly, despite the use of distinct carbaborane anions, all the materials feature one-dimensional (1D) coordination networks with most of the bulky anions, particularly all the phenyl-carbaborane anion [PhCB9H9](-), [PhCB9H8I](-), and [PhCB11H5I6](-), incorporated in the coordination networks through Ag center dot center dot center dot H-B coordinative interactions or Ag center dot center dot center dot I-B coordination bonds. However, the influence of the distinct carbaborane anions is dearly reflected in the coordination features of Ag(I) centers, since all of them are engaged in different combinations of interactions (coordination bonds Ag-N and Ag-I and both coordinative or electrostatic Ag center dot center dot center dot H-B interactions) and in the overall characteristics of the 1D coordination networks.