organic compounds
The crystal structure of the anhydrous 1:1 proton-transfer compound of 5-sulfosalicylic acid (3-carboxy-4-hydroxybenzenesulfonic acid) with 4-aminobenzoic acid, viz. 4-carboxyanilinium 3-carboxy-4-hydroxybenzenesulfonate, C7H8NO2+·C7H5O6S−, displays a hydrogen-bonded polymeric network structure involving primarily all aminium H-atom donors and sulfonate O-atom acceptors, and is propagated through homomolecular cyclic tail-to-tail interactions between the carboxylic acid substituent groups of both cation and anion species. In addition, there are some cation–anion π–π stacking associations.
organic compounds
The crystal structure of cytosinium 3,5-dinitrosalicylicate (systematic name: 6-amino-2-oxo-2,3-dihydropyrimidinium 3,5-dinitrosalicylate), C4H6N3O+·C7H3N2O7-, shows the presence of a primary heteroionic cyclic R22(8) interaction between the H-atom donors of the protonated cytosinium cation and the carboxylate O-atom acceptors of the 3,5-dinitrosalicylate anion. Additional peripheral hydrogen-bonding interactions involving all available cytosinium H-atom donors and both phenol and nitro O-atom acceptors of the anion species give a three-dimensional polymeric structure.
organic compounds
The low-temperature (130 K) crystal structure of the 1:1 proton-transfer compound of 3,5-dinitrosalicylic acid (DNSA) with diethylamine, viz. diethylaminium 3,5-dinitrosalicylate, C4H12N+·C7H3N2O7−, shows the presence of conformationally extended diethylaminium cations in which both H atoms of the aminium centres participate in three-centre hydrogen-bonding associations [one R12(4) and the other R12(6)] with carboxyl, phenol and nitro O-atom acceptors of two separate DNSA anion species [NO = 2.813 (3)–3.320 (3) Å]. These result in 12-membered cyclic R64(12) associations linking the two sets of hetero-species into discrete centrosymmetric tetramers which have no significant peripheral extensions.
organic compounds
In the title compound (systematic name: 2,3-dimethoxy-10-oxostrychnidinium 2-carboxy-6-nitrophthalate dihydrate), C23H27N2O4+·C8H4NO6−·2H2O, the carboxylic acid and carboxylate groups of the hydrogenphthalate anions form head-to-tail catemeric chains of strong intermolecular O—HO hydrogen bonds [OO distance = 2.563 (5) Å] along the 21 screw axes parallel to the a axis. The chains further associate with the water molecules, forming sheet structures parallel to (010). The protonated N atom at the 19-position of the brucine molecule forms a peripheral intermolecular hydrogen bond with the carboxylate group of the anion.
organic compounds
The low-temperature (130 K) structure of the 1:1 proton-transfer compound of brucine with toluene-4-sulfonic acid (systematic name: 2,3-dimethoxy-10-oxostrychnidinium toluene-4-sulfonate trihydrate), C23H27N2O4+·C7H7O3S-·3H2O, has been determined. The asymmetric unit contains two cations, two anions and six molecules of water. Brucinium cations form the familiar undulating head-to-tail ribbon structures, which associate with the toluene-4-sulfonate anions and the water molecules in the interstitial cavities through hydrogen-bonding associations involving all available donor and acceptor atoms on all species. The result is a framework polymer structure.
organic compounds
The crystal structure of the anhydrous 1:1 proton-transfer compound of 5-sulfosalicylic acid (3-carboxy-4-hydroxybenzenesulfonic acid) with 3-aminobenzoic acid, C7H8NO2+·C7H5O6S−, shows heteromeric cyclic R22(8) carboxylic acid dimers formed through hydrogen-bonding interactions between the cation and anion species. Aminium–sulfonate N—HO interactions link these dimers into zigzag chains and also give interchain associations. Cation–anion π–π ring interactions are also present, resulting in a three-dimensional layered polymer structure.