Supramolecular Assemblies in Salts of 2,2′-Biimidazole with 5-Sulfosalicylic Acid and 3,4,5-Trihydroxybenzoic Acid

✍ Scribed by Yan-Ping LI; Pin YANG

• Publisher: John Wiley and Sons
• Year: 2007
• Tongue: English
• Weight: 217 KB
• Volume: 25
• Category: Article
• ISSN: 0256-7660
• DOI: 10.1002/cjoc.200790317

✦ Synopsis

Abstract

Supramolecular assemblies of 2,2′‐biimidazole with 5‐sulfosalicylic acid and 3,4,5‐trihydroxybenzoic acid, have been synthesized and characterized by single‐crystal X‐ray diffraction methods. Both the two proton‐transfer compounds of 2,2′‐biimidazole with 3‐carboxy‐4‐hydroxybenzenesulfonic acid (5‐sulfosalicylic acid, 5‐SSA) [namely bis(2‐(2‐1__H__‐imidazolyl)‐1__H__‐imidazolium) 4‐hydroxybenzene‐3‐carboxylate‐1‐sulfonate monohydrate, 2(C~6~H~7~N~4~)^+^· C~7~H~4~O~6~S^2−^·H~2~O, (I)] and 3,4,5‐trihydroxybenzoic acid [namely 2,2′‐bi‐1__H__‐imidazolium bis(3,4,5‐trihydroxybenzoate) tetrahydrate, C~6~H~8~N~4~^2+^·2(C~7~H~5~O~5~)^−^·4(H~2~O), (II)] feature extensively hydrogen‐bonded three‐dimensional network structures having significant interlayer π‐ π interactions between the cation and anion species. In I, a 5‐SSA^2−^ dianionic species results from deprotonation of both the sulfonic and the carboxylic acid groups, all available O‐atom acceptors interact with all cation and water molecule donors by hydrogen bonds. In II, the formula unit displays a crystallographic inversion symmetry. The structural information about the two complexes between 2,2′‐biimidazole compound and benzenecarboxylic acids obtained in this work will be particularly important for the rational design of supramolecular organic functional materials.