A series of silver(i) pyridone-sulfonates with 1-D “butterfly” chain, 2-D lamellar network and 3-D pillared layered frameworks: syntheses, structures and characterizations

Abstract

A series of silver(I) pyridone-sulfonates, namely [Ag₅(HL1)₃(NO₃)₂(H₂O)]_n (1) [Ag₂(HL1)₂]_n·2nH₂O (2), [Ag₂(HL1)(NO₃)]_n (3), and [Ag₃(HL2)₂(NO₃)(H₂O)]_n (4) (HL1 = 4(1H)-pyridone-3-sulfonate monoanion, HL2 = 2(1H)-pyridone-5-sulfonate monoanion), have been synthesized and characterized by elemental analyses, IR, TG, PL and X-ray analyses. Complex 1, which exhibits a novel continuous silver polyhedral framework containing four kinds of coordination spheres, has been recently reported. Complex 2 presents the first one-dimensional (1-D) “butterfly” array composed of SO₃-bridged columns of Ag(I) ions and symmetric pendant organic groups in silver(I) sulfonates, while complex 3 possesses a two-dimensional (2-D) layer structure in which the inorganic network substructure consists of helical chains of edge-sharing Ag1 distorted octahedra linked through dimers of edge-sharing Ag2 distorted anti-trigonal prisms by sharing two corners and two edges. Replacing H₂L1 by H₂L2 leads to the formation of complex 4, a three-dimensional (3-D) pillared layered framework, which is also extended by the rare μ₄ nitrate anion. In complexes 1–4, all the inorganic parts can be considered as being built up from versatile polyhedra of silver(I) centers by sharing corners, edges or faces. The sulfonic group shows some novel coordination modes, which is first reported here. Solid-state fluorescence quenching and thermal stability are discussed for all of these complexes.