[Ag2(aca)2]n and [Ag4(aca)4(NH3)2] (acaH = 9-anthracenecarboxylic acid): Synthesis, X-ray crystal structures, antimicrobial and anti-cancer activities

[Ag2(9-aca)2]n and [Ag4(9-aca)4(NH3)2] (9-acaH = 9-anthracenecarboxylic acid) have been prepared and structurally characterized. [Ag2(9-aca)2]n consists of polymeric ribbons of linked disilver(I) syn–syn bridged dicarboxylate units. [Ag4(9-aca)4(NH3)2] is tetrameric and centrosymmetric, with two syn–syn bridging carboxylates linked to the bimetallic Ag–Ag core and a further two syn–anti bridged carboxylate ligands in the equatorial plane, being coordinated to one Ag in the bimetallic core and to a second Ag, with the latter also bonded to an NH3 ligand. In vitro studies show that both complexes are extremely cytotoxic against selected human fungal and bacterial pathogens, and each complex also greatly inhibits the growth of two mammalian cancer cell lines.