Self-Assembly of Two 2-Sulfobenzoic Supramolecular Architectures with New Topological Networks

Two proton-transfer compounds of 2-sulfobenzoic acid, namely [(2-sb)·(2-apyH)2] (1) and [(2-sbH)·(TTF)·2(H2O)] (2) have been obtained and characterized by single-crystal X-ray analyses, elemental analyses, IR spectra, TG analyses and fluorescence studies, where 2-sb is 2-sulfobenzoate dianion, 2-sbH is 2-sulfobenzoate monoanion, 2-apyH is protonated 2-aminopyridine and TTF is tetrathiafulvalene. The different counter ligands lead to diverse existing motifs of 2-sulfobenzoate, network expanded forms and topological architectures. In 1, hydrogen bonds connect 2-sb and 2-apyH ligands to form hydrogen-bonded dimer structure, in which two R 2 2 (8) motifs occur. In 2, the hydrogen-bonded chain of 2-sbH and water molecules is expanded into layer by the R 2 2 (14) motif of two 2-sbH monoanion and stacked dimers of TTF+ cations. The formal charge on TTF is +1. The 2-sb/2-sbH anions form hydrogen bonds in the networks to act as 7 and 3-connected nodes with topologies of {42·5}2{48·56·66·8} and {6·102}{62·10} in compounds 1 and 2 respectively. The results showed that the structural diversity of the compounds resulted from the different environment of 2-sb/2-sbH ligands. Solid state properties such as thermal stability and luminescence of the complexes have been investigated. In the paper, two three-dimensional 2-sulfobenzoic supramolecular architectures were reported with new topological networks analyzed, two distinct categories of hydrogen-bonded supramolecular synthons: supramolecular homosynthons and supramolecular heterosynthons occur in the two structures, in which the different counter ligands led to diverse existing motifs of 2-sb, network expanded forms and topological architectures, and the relationship between the solid state properties such as thermal stability and luminescence of the complexes and their structures was discussed.