Silver cages with encapsulated acetylenediide as building blocks for hydrothermal synthesis of supramolecular complexes with n-cyanopyridine and pyridine-n-carboxamide (n = 3, 4)

Abstract

New silver(I) double salts (Ag₂C₂)(AgCF₃CO₂)₈(3-pyCONH₂)₂(H₂O)₄ (1), [(Ag₂C₂)(AgCF₃CO₂)₄(4-pyCONH₂)(H₂O)]·H₂O (2), (Ag₂C₂)(AgCF₃CO₂)₆(3-pyCONH₂)₄ (3), (Ag₂C₂)(AgCF₃CO₂)₆(3-pyCN)₂ (4) and (Ag₂C₂)(AgCF₃CO₂)₄(4-pyCN)₂ (5) (n-pyCONH₂ is pyridine-n-carboxamide, n-pyCN is n-cyanopyridine; n = 3, 4) have been synthesized by the hydrothermal method. All five compounds contain polyhedral silver(I) cages each encapsulating a C₂²⁻ dianion. Compounds 1, 3, 4 and 5 exhibit three-dimensional structures, whereas compound 2 is a two-dimensional network. The structure of 1 is constructed from the linkage of a branched-tree architecture via hydrogen bonds. Unlike 4 and 5, which involve the connection of n-cyanopyridine (n = 3, 4) with silver columns, 3 results from the linkage of discrete silver cages via pyridine-3-carboxamide.