Diverse intermolecular interactions in silver(I)-organic frameworks constructed with flexible supramolecular synthons

Three ligands bearing terminal ethynide moiety attached via pendent arm to a phenyl skeleton have been used in synthesis of three silver (I) complexes, namely, [(AgL1)(AgCF3CO2)3]n (1), {[(AgL2)(AgCF3CO2)6(H2O)2]·(H2O)6}n (2) and [(AgL3)·(AgCF3CO2)5(H2O)]n (3), in which several unconventional intermolecular interactions (silver-ethynyl, silver–aromatic, argentophilicity and C−H···π) have been shown to play vital role in the formation and stabilization of supramolecular structures. In 1, butterfly-shaped Ag4 baskets are interconnected together by trifluoroacetate groups to lead to a layer structure, which is also consolidated by silver–aromatic interactions, adjacent layers are then linked into a three-dimensional supramolecular architecture through weak C−H···F hydrogen bonding. In 2, ladder type chains are associated into three-dimensional supramolecular architecture through a rich hydrogen-bonding system. In 3, square-pyramidal Ag5 baskets are also fused together by the trifluoroacetate groups with the assistance of argentophilic interactions and silver–aromatic interaction give rise to a 2D coordination network, which are further united by C−H···π interaction to produce a three-dimensional supramolecular framework.

A series of three silver-ethynide complexes have been obtained. Among them, several unconventional intermolecular interactions (silver-ethynyl, silver–aromatic, argentophilicity and C–H···π)) have been shown to play vital role in the formation and stabilization of supramolecular structures.Figure optionsDownload as PowerPoint slideHighlights
► Several unconventional intermolecular interactions play vital role in assembling supramolecular structures.
► Silver-organic frameworks have been obtained.
► Flexible ligands can adopt μ4- and μ5-ligation modes upon bonding to silver(I) centers.