Two-dimensional hydrogen-bonded supramolecular networks in the compounds of benzene-1,2,4,5-tetracarboxylic acid (pyromellitic acid) with 2,2′-biimidazole and 4,4′-dimethyl-2,2′-bipyridine

• Published in: Acta crystallographica. Section C, Crystal structure communications Crystal structure communications, 2013-12, Vol.69 (12), p.1537-1540
• Main Author: Zhong, Kai-Long
• Format: Article
• Language: English
• Subjects: 2,2′‐biimidazole; 2′-biimidazole; 2′-bipyridine; 4,4′‐dimethyl‐2,2′‐bipyridine; 4′-dimethyl-2; Atomic structure; Chemical reactions; crystal structure; hydrogen bonding; Hydrogen bonds; Molecular biology; pyromellitic acid
• ISSN: 0108-2701; 1600-5759
• DOI: 10.1107/S0108270113030801

Two products from the proton‐transfer reactions of benzene‐1,2,4,5‐tetracarboxylic acid (pyromellitic acid, PMA) with 2,2′‐biimidazole and 4,4′‐dimethyl‐2,2′‐bipyridine, namely 2,2′‐biimidazole‐3,3′‐diium 2,5‐dicarboxybenzene‐1,4‐dicarboxylate, C6H8N42+,C10H4O82−, (I), and 4‐methyl‐2‐(4‐methylpyridin‐2‐yl)pyridinium 2,4,5‐tricarboxybenzoate monohydrate, C12H13N2+·C10H5O8−·H2O, (II), have been prepared and their structures determined. Both compounds crystallize in the space group P. The asymmetric unit of (I) is composed of two independent ion pairs. Both the 2,2′‐biimidazole‐3,3′‐diium dication and the PMA2− anion are located on special positions (inversion centres). The protonated 2,2′‐biimidazole‐3,3′‐diium ring H atoms are involved in hydrogen bonding with carboxylate O atoms to form one‐dimensional hydrogen‐bonded chain structures. Adjacent chains are further linked via carboxyl–carboxyl O—H...O hydrogen bonding, resulting in a two‐dimensional supramolecular sheet with the R65(34) motif extending in the (11) plane. In (II), classical O—H...O hydrogen‐bond‐linked anion–anion units are extended into a one‐dimensional chain running parallel to the [100] direction, giving an R22(8)R44(30) motif. The chains are connected by water–carboxyl O—H...O hydrogen bonds to form a two‐dimensional network parallel to the (01) plane. The 4‐methyl‐2‐(4‐methylpyridin‐2‐yl)pyridinium cations lie between the two‐dimensional supramolecular layers linked via N—H...O hydrogen‐bonding interactions.