Powder route to crystal structures: X-ray powder diffraction determination of polymeric silver imidazolate

Abstract

Silver imidazolate has been synthesized and its solid-state structure determined, ab initio, from conventional X-ray powder diffraction data only. The crystals are orthorhombic, space group P2₁2₁2₁, with a= 5.5759(4), b= 6.7452(4), c= 22.174(1)Å, U= 834.0(1)ų, Z= 8, D_c= 2.786 g cm^–3. The structure was solved by a real-space scavenger technique and refined by the Rietveld method down to R_P and R_F values of 0.062 and 0.027, respectively, for 4401 data points (1262 reflections) measured at room temperature in the 17–105°(2θ) range. The crystal structure of [{Ag(im)}_n](Him = imidazole) consists of a complex packing of polymeric chains folding about the crystallographic c axis, containing linearly co-ordinated silver atoms joined by imidazolate fragments. Short interchain Ag Ag contacts [3.161(4)Å] were observed.