Dinuclear silver(i) complexes for the design of metal–ligand networks based on triazolopyrimidines

Abstract

Silver(I) coordination complexes with the versatile and biomimetic ligands 1,2,4-triazolo[1,5-a]pyrimidine (tp), 5,7-dimethyl-1,2,4-triazolo[1,5-a]pyrimidine (dmtp) and 7-amine-1,2,4-triazolo[1,5-a]pyrimidine (7atp) all feature dinuclear [Ag₂(μ-tp)₂]²⁺ building units (where tp is a triazolopyrimidine derivative), which are the preferred motif, independently of the counter-anion used. According to AIM (atoms in molecules) and ELF (electron localization function) analyses, this fact is due to the great stability of these dinuclear species. The complexes structures range from the dinuclear entities [Ag₂(μ-tp)₂(CH₃CN)₄](BF₄)₂ (1), [Ag₂(μ-tp)₂(CH₃CN)₄](ClO₄)₂ (2), [Ag₂(μ-7atp)₂](ClO₄)₂ (3) and [Ag₂(μ-dmtp)₂(CH₃CN)](PF₆)(ClO₄) (4) over the 1D polymer chain [Ag₂(μ-CF₃SO₃)₂(μ-dmtp)₂]_n (5) to the 3D net {[Ag₂(μ₃-tp)₂](PF₆)₂· ∼6H₂O}_n (6) with NbO topology.