New coordination polymers of silver(I) based on dodecahydro-closo-dodecaborate anion: Synthesis and structure

Resumo

It has been demonstrated that the reaction of Cat[Ag[B₁₂H₁₂]] or [Ag₂[B₁₂H₁₂]] with chelating ligands L (L = bipy, phen) leads to the selective formation of stable [(Ag₂(L)₂[B₁₂H₁₂]]_n 1D polymers irrespective of the nature of cation (Cat) in the starting reagent, the ratio of the reaction components, and the solvent used. The structures of [Ag₂(bipy)₂[B₁₂H₁₂]]_n · 2CH₃CN and [Ag₂(phen)₂[B₁₂H₁₂]]_n · DMF have been determined by X-ray crystallography. It has been demonstrated that the [B₁₂H₁₂]²⁻ anion in polymer chains acts as a bridging ligand coordinated to silver atoms through edges or through an edge and a vertex of the icosahedron. The Ag–B(H) and Ag–H(B) distances are within 2.638(3)–3.074(3) and 1.90–2.80 Å, respectively. These complexes are the first examples of 1D coordination polymers based on the [B₁₂H₁₂]²⁻ anion and azaheterocyclic ligands L.