Structural varieties in double salts of silver acetylide containing ancillary anions and terminal ligands

New double salts Ag2C2·6AgO2CCHF2 (1), [HPyCH2OH][Ag9(C2)(CF3CO2)9(HPyCH2OH)(H2O)]·0.5H2O (PyCH2OH=4-(hydroxymethyl)pyridine) (2), Ag2C2·5CF3SO3Ag·2MeCN·2H2O (3) and Ag2C2·8CF3SO3Ag·2EtCN·3H2O (4) have been synthesized by dissolving Ag2C2 in an aqueous solution of the corresponding silver salt followed by the addition of an ancillary ligand. Complex 1 has a three-dimensional structure in which unprecedented basket-like silver cages are inter-connected by difluoroacetate ligands. In 2, centrosymmetric (C2)2@Ag14 double cages with each half taking the shape of a triangulated dodecahedron are linked through additional silver atoms to generate an infinite chain, and unsupported silver(I)–silver(I) interactions exist between neighboring chains. Of the two independent 4-(hydroxymethyl)pyridinium ions in 2, one acts in the O-ligating mode, which is observed for the first time, while the other merely serves to provide charge balance and space-filling. Both 3 and 4 are layer-type structures in which the basic building unit is a distorted monocapped octahedron and monocapped trigonal prism, respectively.