ABSTRACT: In the title ammonium carboxyl-ate-carb-oxy-lic acid co-cystal, C(10)H(9)N(2) (+)·C(8)H(3)I(3)NO(4) (-.)C(8)H(4)I(3)NO(4), the carboxyl-ate anion and carb-oxy-lic acid mol-ecule are linked by O-H?O and N-H?O hydrogen bonds to form a chain running along the c axis of the monoclinic unit cell. The chains are linked by pyridinum and pyridine N-H?O hydrogen bonds, generating a layer motif. O-H?N and O-H?O hydrogen bonds are also observed.
Project description:The racemic title compound, C(9)H(11)NO(4)·H(2)O, a tricyclic rearranged amino-norbornane dicarb-oxy-lic acid, is a conformationally rigid analogue of glutamic acid and exists as an ammonium-carboxyl-ate zwitterion, with the bridghead carb-oxy-lic acid group anti-related. In the crystal, N-H?O and O-H?O hydrogen bonds involving the ammonium, carb-oxy-lic acid and water donor groups with both water and carboxyl O-atom acceptors give a three-dimensional framework structure.
Project description:In the title compound, C(16)H(28)N(4)O(8)·2H(2)O, the 12-membered macrocycle has twofold crystallographic symmetry and the asymmetric unit comprises one half-mol-ecule. The four carbox-yl/carboxyl-ate groups reside on the same side of the macrocycle. The mol-ecule is a double zwitterion with two of the carb-oxy-lic acid H atoms transferred to the two N atoms on the opposite sides of the macrocycle, resulting in both N atoms having positive charges and leaving the two resulting carboxyl-ate groups with negative charges. The two remaining carb-oxy-lic acid groups and the carboxyl-ate groups form O-H?O hydrogen bonds with the crystal water mol-ecules. The H atoms bound to the N atoms within the macrocyle are engaged in two equivalent hydrogen bonds with the adjacent N atoms.
Project description:The title salt, C(8)H(20)N(+)·C(22)H(27)O(3)S(-), is a proton-transfer compound derived from the recently reported parent carb-oxy-lic acid [Alhadi et al. (2010). Acta Cryst. E66, o1787] by the addition of a second equivalent of di-n-butyl-amine, yielding the di-n-butyl-ammonium carboxyl-ate salt. The structure of the carboxyl-ate anion resembles that of the parent carb-oxy-lic acid. The main difference lies in the position of the H atom in the 4-hy-droxy group. In the anion the O-H bond is perpendicular, rather than parallel, to the benzyl ring. This position appears to facilitate hydrogen bonding to an O atom of the carboxyl-ate group of a symmetry-related anion. In addition, there are three N-H?O hydrogen bonds. In contrast, the neutral species hydrogen bonds via a carboxylic acid dimer. The dihedral angle between the benzene rings in the anion is 79.19?(7)°.
Project description:The title compound, C(9)H(10)N(2)O(4)·H(2)O, was obtained as a zwitterion derived from the nucleophilic attack of 3-amino-pyridine on the fumaric ?,?-system. Within the molecule, the amino-pyridine moiety and the carboxyl-ate and carb-oxy-lic acid fragments form dihedral angles of 68.6?(2) and 62.8?(2)°, respectively. The geometry adopted by the mol-ecule does not allow the formation of centrosymmetric dimeric hydrogen-bonded units; instead chains along the a axis are linked by COO-H?OOC motifs. These chains are inter-connected by N-H?O and O-H?O hydrogen bonds involving the carb-oxy-lic acid and carboxyl-ate units and the solvent water mol-ecules.
Project description:2-Amino-pyridine and citric acid mixed in 1:1 and 3:1 ratios in ethanol yielded crystals of two 2-amino-pyridinium citrate salts, viz. C5H7N2+·C6H7O7- (I) (systematic name: 2-amino-pyridin-1-ium 3-carb-oxy-2-carb-oxy-methyl-2-hy-droxy-propano-ate), and 3C5H7N2+·C6H5O73- (II) [systematic name: tris-(2-amino-pyridin-1-ium) 2-hy-droxy-propane-1,2,3-tri-carboxyl-ate]. The supra-molecular synthons present are analysed and their effect upon the crystal packing is presented in the context of crystal engineering. Salt I is formed by the protonation of the pyridine N atom and deprotonation of the central carb-oxy-lic group of citric acid, while in II all three carb-oxy-lic groups of the acid are deprotonated and the charges are compensated for by three 2-amino-pyridinium cations. In both structures, a complex supra-molecular three-dimensional architecture is formed. In I, the supra-molecular aggregation results from Namino-H?Oacid, Oacid?H-Oacid, Oalcohol-H?Oacid, Namino-H?Oalcohol, Npy-H?Oalcohol and Car-H?Oacid inter-actions. The mol-ecular conformation of the citrate ion (CA3-) in II is stabilized by an intra-molecular Oalcohol-H?Oacid hydrogen bond that encloses an S(6) ring motif. The complex three-dimensional structure of II features Namino-H?Oacid, Npy-H?Oacid and several Car-H?Oacid hydrogen bonds. In the crystal of I, the common charge-assisted 2-amino-pyridinium-carboxyl-ate heterosynthon exhibited in many 2-amino-pyridinium carboxyl-ates is not observed, instead chains of N-H?O hydrogen bonds and hetero O-H?O dimers are formed. In the crystal of II, the 2-amino-pyridinium-carboxyl-ate heterosynthon is sustained, while hetero O-H?O dimers are not observed. The crystal structures of both salts display a variety of hydrogen bonds as almost all of the hydrogen-bond donors and acceptors present are involved in hydrogen bonding.
Project description:Both the 3-amino-2H,4H-1,2,4-triazolium cation and the pyrazine-2-carboxyl-ate anion in the title salt, C2H5N4 (+)·C5H3N2O2 (-), were formed by an unexpected deca-rboxylation reaction, from 5-amino-1H-1,2,4-triazole-3-carb-oxy-lic acid and pyrazine-2,3-di-carb-oxy-lic acid, respectively. The dihedral angle between the pyrazine ring (r.m.s. deviation = 0.008?Å) and the carboxyl-ate group in the anion is 3.7?(3)°. The extended structure of the salt contains a supra-molecular zigzag tape in which cations and anions are engaged in strong and highly directional N-H?N,O hydrogen bonds, forming R 2 (2)(8) and R 2 (2)(9) graph-set motifs. The packing between the tapes is mediated by ?-? stacking inter-actions between the triazole and pyrazine rings.
Project description:The title salt, C2H8N+·C10H5O8-, was the unexpected product of an attempt to prepare a ZrIV metal-organic framework with benzene-1,2,4,5-tetra-carb-oxy-lic acid (1,2,4,5-H3B4C). In the reaction, the DMF solvent has been decarb-on-yl-ated, forming the di-methyl-ammonium cation, with one proton lost from the tetra-carb-oxy-lic acid. It is proposed that the ZrIV salt acts as a Tsotsi or robber, plundering CO from the DMF mol-ecule. The resulting salt crystallizes with two cations and two anions in the asymmetric unit. An intra-molecular hydrogen bond forms between a carb-oxy-lic acid substituent and the carboxyl-ate group of each of the monodeprotonated (1,2,4,5-H3B4C-) anions. In the crystal, an extensive array of O-H?O, N-H?O and C-H?O hydrogen bonds generates a three-dimensional network, with columns of cations and anions forming along the b axis.
Project description:In the preparation of the title hydrated salt, C14H13N2 (+)·C10H5O8 (-)·H2O, a proton has been transfered to the 2,9-dimethyl-1,10-phenanthrolinium cation, forming a 2,4,5-tri-carb-oxy-benzoate anion. In the anion, the mean planes of the protonated carboxyl-ate groups form dihedral angles of 11.0?(5), 4.4?(5) and 80.3?(4)° with the benzene ring to which they are attached. The mean plane of the deprotonated carboxyl-ate group forms a dihedral angle of 10.6?(5)° with the benzene ring. In the crystal, the anions are involved in carb-oxy-lic acid O-H?Ocarbox-yl hydrogen bonds, generating a two-dimensional network parallel to (001) containing R 4 (4)(28) and R 4 (4)(32) motifs. The 2,9-dimethyl-1,10-phenanthrolinium cations and water mol-ecules reside between the anion layers and are connected to the anions via N-H?Owater and Owater-H?Ocarbox-yl hydrogen bonds. An intra-molecular O-H?O hydrogen bond is also observed in the anion.
Project description:The crystal structure of the 1:2 dihydrate compound of chloranilic acid (systematic name: 2,5-di-chloro-3,6-dihy-droxy-1,4-benzo-quinone) with 2-carb-oxy-pyridine (another common name: picolinic acid; systematic name: pyridine-2-carb-oxy-lic acid), namely, 2C6H5.5NO20.5+·C6HCl2O4-·2H2O, (I), has been determined at 180?K, and the structure of the 1:2 dihydrate compound of chloranilic acid with 2-carb-oxy-quinoline (another common name: quinaldic acid; systematic name: quinoline-2-carb-oxy-lic acid), namely, 2C10H7NO2·C6H2Cl2O4·2H2O, (II), has been redetermined at 200?K. This determination presents a higher precision crystal structure than the previously published structure [Marfo-Owusu & Thompson (2014 ?). X-ray Struct. Anal. Online, 30, 55-56]. Compound (I) was analysed as a disordered structure over two states, viz. salt and co-crystal. The salt is bis-(2-carb-oxy-pyridinium) chloranilate dihydrate, 2C6H6NO2+·C6Cl2O42-·2H2O, and the co-crystal is bis-(pyridinium-2-carboxyl-ate) chloranilic acid dihydrate, 2C6H5NO2·C6H2Cl2O4·2H2O, including zwitterionic 2-carb-oxy-pyridine. In both salt and co-crystal, the water mol-ecule links the chloranilic acid and 2-carb-oxy-pyridine mol-ecules through O-H?O and N-H?O hydrogen bonds. The 2-carb-oxy-pyridine mol-ecules are connected into a head-to-head inversion dimer by a short O-H?O hydrogen bond, in which the H atom is disordered over two positions. Compound (II) is a 1:2 dihydrate co-crystal of chloranilic acid and zwitterionic 2-carb-oxy-quinoline. The water mol-ecule links the chloranilic acid and 2-carb-oxy-quinoline mol-ecules through O-H?O hydrogen bonds. The 2-carb-oxy-quinoline mol-ecules are connected into a head-to-tail inversion dimer by a pair of N-H?O hydrogen bonds.
Project description:4-[(Morpholin-4-yl)carbothioyl]benzoic acid, C12H13NO3S, a novel phen-yl(morpholino)methane-thione derivative, crystallizes in the monoclinic space group P21/n. The morpholine ring adopts a chair conformation and the carb-oxy-lic acid group is bent out slightly from the benzene ring mean plane. The mol-ecular geometry of the carb-oxy-lic group is characterized by similar C-O bond lengths [1.266?(2) and 1.268?(2)?Å] as the carboxyl-ate H atom is disordered over two positions. This mol-ecular arrangement leads to the formation of dimers through strong and centrosymmetric low barrier O-H?O hydrogen bonds between the carb-oxy-lic groups. In addition to these inter-molecular inter-actions, the crystal packing consists of two different mol-ecular sheets with an angle between their mean planes of 64.4?(2)°. The cohesion between the different layers is ensured by C-H?S and C-H?O inter-actions.