Assembly of silver(i)–organic frameworks from flexible supramolecular synthons with pendant ethynide arm attached to biphenyl and phenoxybenzene skeletons

Abstract

A series of six silver(I) complexes bearing terminal ethynide moiety attached via pendant arm to biphenyl and phenoxybenzene skeletons of two new ligands have been synthesized. In these compounds, the invariable appearance of the μ₃-, μ₄- and μ₅-ligation modes of the ethynide moiety reaffirms the general utility of the silver–ethynide supramolecular synthons L ⊃ Ag_n (n = 3–5) in coordination network assembly. In complexes 1, 2, 4, and 5, silver(I)–aromatic interactions play important roles in assembling a series of silver–organic frameworks. Notably, an unusual π⋯Ag₄⋯π sandwich unit makes it appearance in complex 2, which is the first example in silver–ethynide complexes. An argentophilic layer is found in complex 3. In addition, a two-fold interpenetrating 3D supramolecular framework based on discrete Ag₈ aggregate is found in complex 6. In the solid state, their luminescence behaviors have been studied.