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···H–B coordinative
interactions or Ag···I–B coordination bonds.
However, the influence of the distinct carbaborane anions is clearly
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···H–B interactions) and in the overall characteristics
of the 1D coordination networks.