Preparation and crystal structure of polymeric ammonium silver(I) citrate hydrate, {NH 4[Ag 2(C 6H 5O 7)(H 2O)]} n

Abstract

The polymeric silver(I) citrate complex {NH 4[Ag 2(C 6H 5O 7)(H 2O)]} n has been synthesized and its structure determined by X-ray diffraction methods and refined to R = 0.046 for 2520 observed reflections. This compound represents the first reported complexes of a silver(I) citrate. In the structural repeating unit there are two independent but different carboxylato(O,O′) bridged silver dimers [AgAg, 2.845, 2.846(1) Å] linked into infinite linear chains by the terminal carboxyl groups of the citrato(3 −) ligands. With one dimer, the AgO (axial) bonds are to oxygens from the sub-terminal carboxylate groups of two independent silver citrate chains. The second silver dimer also forms links with adjacent chains via axial AgO(carboxylate) bonds, while in the remaining axial sites are water molecules. The mean AgO distance is 2.377(4) Å. The result is a novel convoluted anionic chain sheet structure.