1609326-17-1Relevant articles and documents
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
Zhong, Kai-Long
, p. 1537 - 1540 (2014/01/06)
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, C6H 8N4 2+,C10H4O8 2-, (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 R 6 5(34) motif extending in the (1 1) 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 R 2 2(8)R 4 4(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.
