Ammine(2,2′-bipyridine-κ2N,N′)-silver(I) nitrate: a dimer formed by π-π stacking and ligand-unsupported Ag•••Ag interactions

Reaction of AgNO3 and 2,2'-bipyridine (bipy) under ultrasonic treatment gave the title compound, [Ag(C10H8N2)(NH3)]NO3. The crystal structure consists of dimers formed by two symmetry-related Ag-I-bipy monomers connected through intra-dimer pi-pi stacking and ligand-unsupported Ag center dot center dot center dot Ag interactions. A crystallographic C2 axis passes through the mid-point of and is perpendicular to the Ag center dot center dot center dot Ag-i(-x + 1, y, -z + 1/2) axis. In addition, each Ag I cation is coordinated by one chelating bipy ligand and one ammine ligand, giving a trigonal coordination environment capped by the symmetry-equivalent Ag atom. Molecules are assembled by Ag center dot center dot center dot Ag, pi-pi, hydrogen-bond (N-H center dot center dot center dot O and C-H center dot center dot center dot O) and weak Ag center dot center dot center dot pi interactions into a three-dimensional framework. Comparing the products synthesized under different mechanical treatments, we found that reaction conditions have a significant influence on the resulting structures. The luminescence properties of the title compound are also discussed.