Two three-dimensional networks in the binary molecular adducts 4-methylimidazolium hydrogen terephthalate and bis(4-methylimidazolium) terephthalate

Abstract

Both the 1:1 and 2:1 molecular adducts of 4-methylimidazole (4-MeIm) and terephthalic acid (H2TPA) are organic salts, viz. C4H7N2+.C8H5O4-, (I), and 2C4H7N2+.C8H4O4(2-), (II), respectively. The component ions in (I) are linked by N-H...O and O-H...O hydrogen bonds into continuous two-dimensional layers built from R6(4)(32) hydrogen-bond motifs running parallel to the (100) plane. These adjacent two-dimensional layers are in turn linked by a combination of C-H...O, C-H...pi and pi-pi interactions into a three-dimensional network. In the crystal structure of (II), with the anion located on an inversion centre, only N-H...O hydrogen bonds result in two-dimensional layers built from R8(8)(42) hydrogen-bond motifs running parallel to the (102) plane. Being similar to those in (I), these layers are also linked by means of C-H...O, C-H...pi and pi-pi interactions, forming a three-dimensional network. This study indicates that, on occasion, a change of the reactant concentration can exert a pivotal influence on the construction of supramolecular structures based on hydrogen bonds.

Three-dimensional supramolecular architecture in imidazolium hydrogen 2,3,5,6-tetrafluoroterephthalate

“…+ cations linked to opposite sides of the same Htfbdc À anion chain are almost perpendicular to one another [dihedral angle = 82.0 (1) ], while the dihedral angle between the Htfbdc À rings of different chains is 23.5 (1) . This pattern is somewhat different from what is seen in the two-dimensional layers formed by similar strong O-HÁ Á ÁO and N-HÁ Á ÁO hydrogen bonds with an R 4 6 (32) ring pattern in 4-methylimidazolium hydrogen terephthalate (Meng et al, 2008), in which the Htfbdc À anions of adjacent chains are parallel to each other and all 4-methylimidazolium cations are oriented in the same direction, so that the resulting (4,4) network layers are also parallel to each other.…”

“…The distance between the two carboxyl O atoms in the hydrogen bond is slightly shorter than those seen in other carboxylic acid compounds, such as terephthalic acid (2.620 Å ; Domenicano et al, 1990) and bis(2,4 0 -bipyridin-1 0 -ium) 2,5-dicarboxybenzene-1,4-carboxylate benzene-1,2,4,5-tetracarboxylic acid (2.607 Å ; Cui et al, 2005), indicating the strength of the interactions in (I). The linear tapes are very similar to the one-dimensional chains formed by the hydrogen terephthalate anions in 4-methylimidazolium hydrogen terephthalate (Meng et al, 2008).…”

“…The compound is thus shown to be an organic proton-transfer binary salt, in which the acidic H atom of one carboxyl group is transferred to an imidazole N atom while the other carboxyl group remains as the acid. The carboxyl and carboxylate groups are distinctly twisted away from the arene ring, with dihedral angles of 49.1 (1) and 51.5 (1) , respectively, notably larger than the corresponding values in 4-methylimidazolium hydrogen terephthalate [5.7 (1) and 21.9 (1) , respectively; Meng et al, 2008]. The plane of the aromatic ring of the Htfbdc À anion is inclined at 40.9 (1) to that of the ImH 2 et al, 2008].…”

A two-dimensional network in the molecular salt 2-methylimidazolium hydrogen glutarate, and three-dimensional networks in the salts 2-methylimidazolium hydrogen succinate and 2-methylimidazolium hydrogen adipate monohydrate

“…In a continuation of our studies of organic salts formed by organic acids and imidazole derivatives (Meng, Xiao et al, 2008;Meng, Lin & Li, 2008;Zhou et al, 2009), we now report our findings on the three title compounds, (I)-(III), formed by aliphatic diacids and 2-methylimidazole (2-MeIm).…”

A new polymorph of 1,4-bis(imidazol-1-ylmethyl)benzene dihydrate and its hydrogen-bonded fivefold interpenetrated CdSO4network

“…As a flexible ligand, bix has often been used in the synthesis of metal-organic frameworks as a linker molecule (Hoskins et al, 1997a;Abrahams et al, 2002;Carculli et al, 2005;Wen et al, 2005;Zhang et al, 2005) and in the construction of hydrogen-bonded supramolecular assemblies as hydrogenbonding acceptors Shen et al, 2004;Aakerö y et al, 2005Aakerö y et al, , 2006Zhang et al, 2007). Recently, as a result of our interest in exploring the selfassembling nature of carboxylic acids with Lewis bases (Meng et al, 2007;Meng, Lin & Li, 2008;Meng, Xiao, Wang & Liu, 2008;Meng, Xiao, Zhang & Zhou, 2008), we have resynthesized the N-containing Lewis base bix by the standard procedure (Hoskins et al, 1997b).…”