Silver(I)-organic networks assembled with the flexible prop-2- ynyloxybenzene ligand: In situ recrystallization and unusual silver-aromatic interaction

A new ligand bearing a pendant terminal ethynide moiety attached to a phenyl ring skeleton has been used in the synthesis of four silver(I) complexes: [(AgL)₂ . (AgCF₃CO₂)₄ . (H ₂O) . (CH₃CN)] (1), [(AgL)₂ . (AgCF ₃CO₂)₄ . (H₂O)] (2), [(AgL) . (AgC₂F₅CO₂)₈ . (H₂O) ₂ . (CH₃CN)₂] (3), and [(AgL) . (AgC ₂F₅CO₂)₂ . (H₂O) ₃] . H₂O (4) (HL ) prop-2-ynyloxybenzene). In this series of compounds, the invariable appearance of the μ4 and μ5 ligation modes of the ethynide moiety affirms the general utility of the silver-ethynide supramolecular synthon C₆H₅OCH₂C=C Ag _n (n = 4, 5) in coordination network assembly. For 1, squarepyramidal Ag₅ baskets are fused into silver(I) columns, which are further associated through hydrogen bonding and aryl π ⋯ π and oxo lone pair ⋯ π interactions to give a 3D supramolecular structure. Interestingly, in situ recrystallization of 1 in its mother liquor leads to loss of the coordinated acetonitrile molecule to yield the 2D metal-organic network of 2, in which the phenyl ring coordinates to a bent trinuclear silver(I) unit. In 3 and 4, an unusual silver-aromatic interaction involving a η3-phenyl ring links 2D networks to generate a 3D metal-organic framework.