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Supramolecular Motifs (supramolecular + motif)
Selected AbstractsSupramolecular motifs in the first structures of organic carboxylate salts of 1-(diaminomethylene)thiourea (HATU)ACTA CRYSTALLOGRAPHICA SECTION C, Issue 8 2009gorzata Ho The structures of the first two organic carboxylate salts of 1-(diaminomethylene)thiourea (HATU), namely 1-(diaminomethylene)thiouron-1-ium formate, C2H7N4S+·HCOO,, (I), and bis[1-(diaminomethylene)thiouron-1-ium] oxalate dihydrate, 2C2H7N4S+·C2O42,·2H2O, (II), in which the oxalate lies on a symmetry centre, possess different extended hydrogen-bonding networks with different graph-set motifs. The R22(8) motif present in (I) does not appear in (II), but an R21(6) motif is present in both (I) and (II). Compound (I) has a three-dimensional hydrogen-bonding network, whereas (II) has a layered structure with layers joined by hydrogen-bonding motifs that form R42(8) patterns. This work extends the known supramolecular structural data for HATU to include these organic carboxylates in addition to the previously characterized salts with inorganic acids. [source] A combined computational and experimental approach for investigating a hydrogen-bonded supermolecular compound comprising benzimidazole and malonic acidINTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY, Issue 3 2008Fang-Fang Jian Abstract A hydrogen-bonded tetramer supramolecular motif of 2:2 benzimidazole (BIZ) and malonic acid (MLA) has been synthesized and characterized by elemental analysis, infrared (IR), and X-ray single crystal diffraction. Thermal stability analyses demonstrate that this supramolecular adduct is a new material and it is not the ordinary superposition of the original monomers. Density function theory (DFT) calculations for the models of dimers, trimers, and tetramer comprising BIZ and MLA have been carried out at B3LYP/6-31G* and PBE1PBE/6-31G* levels of theory, respectively. By comparing the calculated results with the experiments (single crystal structure, IR spectra, and thermal analysis) and based on the statistic thermodymnamic calculations, it is concluded that the dimers cannot exist at room temperature and the tetramer can simulate the title supramolecular complex better than the two trimers. Further studies on the model of tetramer indicate that the hydrogen bond of N···HO is stronger than that of O···HN. © 2007 Wiley Periodicals, Inc. Int J Quantum Chem, 2008 [source] Double anomeric effects and a hydrogen-bonded supramolecular motif in N,N,-bis(3-nitrophenyl)methanediamineACTA CRYSTALLOGRAPHICA SECTION C, Issue 12 2009Zhenfeng Zhang In the title compound, C13H12N4O4, the molecule lies on a crystallographic twofold axis. Molecules are linked into complex sheets parallel to (100) via one N,H...O and two C,H...O hydrogen bonds. Within the molecule, the 3-nitroanilino fragment is essentially planar, and the C,N,C,N,C fragment assumes a nearly perpendicular/perpendicular conformation, with C,N,C,N torsion angles of 81.18,(18)°, which is controlled by a pair of adjacent anomeric interactions. The findings constitute the first demonstration of two anomeric effects existing in one N,C,N unit. [source] Anomeric effect and hydrogen-bonded supramolecular motif in 5-(3-fluoro-4-methoxyphenyl)-1-[(3-fluoro-4-methoxyphenyl)aminomethyl]-1,3,5-triazinane-2-thioneACTA CRYSTALLOGRAPHICA SECTION C, Issue 11 2009Zhenfeng Zhang In the title compound, C18H20F2N4O2S, the triazinane-2-thione ring adopts an envelope conformation, the ring substituents lie on the same side of the mean plane of the heterocyclic ring and the exo lp,N,C,Ntriaz unit (lp is a lone pair and triaz is the triazinane ring) exhibits an antiperiplanar orientation, which is shown to be governed by strong anomeric effects. Molecules are linked into a complex three-dimensional framework by a combination of two N,H...S hydrogen bonds, three C,H...F hydrogen bonds and a ,,, stacking interaction. [source] Uncommon isonicotinamide supramolecular synthons in copper(II) complexes directed by nitrate and perchlorate anionsACTA CRYSTALLOGRAPHICA SECTION C, Issue 9 2009Marijana ?akovi The title compounds, trans -diaquabis(nitrato-,O)bis(pyridine-4-carboxamide-,N1)copper(II), [Cu(NO3)2(C6H6N2O)2(H2O)2], (I), and trans -diaquatetrakis(pyridine-4-carboxamide-,N1)copper(II) bis(perchlorate), [Cu(C6H6N2O)4(H2O)2](ClO4)2, (II), are composed of mononuclear coordination entities involving CuII ions and isonicotinamide. In (I), the centrosymmetric tetragonally distorted octahedral copper(II) environment contains trans -related isonicotinamide and water molecules in the equatorial plane and two nitrate ions occupying the axial sites. In (II), the equatorial plane of the C2 -symmetric distorted octahedron is built up of four isonicotinamide ligands, while water molecules occupy the axial positions. The complex molecules of (I) and (II) are linked into three-dimensional supramolecular frameworks by O,H...O and N,H...O hydrogen bonds. The nitrate and perchlorate ions are building blocks that disturb the robust R22(8) amide supramolecular motif commonly found in crystal structures of copper,isonicotinamide complexes. [source] Dimeric supramolecular motifs of two carboxylate,guanidinium compoundsACTA CRYSTALLOGRAPHICA SECTION C, Issue 9 2010Muhammad Irfan Ashiq The structures of N -benzyl- N,-{6-[(4-carboxylatobenzyl)aminocarbonyl]-2-pyridylmethyl}guanidinium, C23H23N5O3, (I), and N -[2-(benzylaminocarbonyl)ethyl]- N,-{6-[(4-carboxylatobenzyl)aminocarbonyl]-2-pyridylmethyl}guanidinium monohydrate, C26H28N6O4·H2O, (II), both form three-dimensional supramolecular hydrogen-bonded networks based on a dimeric primary synthon involving carboxylate,guanidinium linkages. The differences in the geometries and hydrogen-bonding connectivities are driven by the additional methylpropionamide group and water of crystallization of (II). [source] Hydrogen-bonded supramolecular motifs in pyrimethaminium 4-methylbenzoate, pyrimethaminium 3-hydroxypicolinate and pyrimethaminium 2,4-dichlorobenzoateACTA CRYSTALLOGRAPHICA SECTION C, Issue 3 2010Kaliyaperumal Thanigaimani In 2,4-diamino-5-(4-chlorophenyl)-6-ethylpyrimidin-1-ium (pyrimethaminium, PMNH) 4-methylbenzoate, C12H14ClN4+·C8H7O2,, (I), pyrimethaminium 3-hydroxypicolinate, C12H14ClN4+·C6H4NO3,, (II), and pyrimethaminium 2,4-dichlorobenzoate, C12H14ClN4+·C7H3Cl2O2,, (III), the PMNH cations interact with the carboxylate groups of the corresponding anion via nearly parallel N,H...O hydrogen bonds, forming R22(8) ring motifs. A description of the observed arrays of quadruple hydrogen bonds in (I) and (II) in terms of hydrogen donors and acceptors (the DA model), their graph-set motifs and the resulting supramolecular ladder is given. In (III), supramolecular chains along the b axis and helical chains along the a axis are formed via N,H...O hydrogen bonds involving the 2-amino and 4-amino groups of the PMNH cation, respectively. Weak Cl...Cl interactions are also found in (III). [source] Inter-ring and endo anomeric effects, and hydrogen-bonded supramolecular motifs in two 2,4,6,8-tetraazabicyclo[3.3.0]octane derivativesACTA CRYSTALLOGRAPHICA SECTION C, Issue 4 2009Zhenfeng Zhang In 2,4,6,8-tetrakis(4-chlorophenyl)-2,4,6,8-tetraazabicyclo[3.3.0]octane, C28H22Cl4N4, the imidazolidine rings adopt envelope conformations, which are favoured by two equal endo anomeric effects. The molecule lies on a crystallographic twofold axis and molecules are linked into a three-dimensional framework via two C,H...Cl hydrogen bonds. In 2,4,6,8-tetrakis(4-methoxyphenyl)-2,4,6,8-tetraazabicyclo[3.3.0]octane, C32H34N4O4, one of the methyl groups is disordered over two sets of sites and the same methyl group participates in an intermolecular C,H...O hydrogen bond, which in turn causes a considerable deviation from the preferred conformation. There are two unequal inter-ring anomeric effects in the N,C,N groups. Molecules are linked into corrugated sheets by one C,H..., hydrogen bond and two independent C,H...O hydrogen bonds involving methoxy groups. [source] Hydrogen-bonded supramolecular motifs in 2-amino-4,6-dimethoxypyrimidinium picrate and pyrimethaminium picrate dimethyl sulfoxide solvateACTA CRYSTALLOGRAPHICA SECTION C, Issue 2 2009Kaliyaperumal Thanigaimani In the crystal structures of 2-amino-4,6-dimethoxypyrimidinium 2,4,6-trinitrophenolate (picrate), C6H10N3O2+·C6H2N3O7,, (I), and 2,4-diamino-5-(4-chlorophenyl)-6-ethylpyrimidin-1-ium (pyrimethaminium or PMN) picrate dimethyl sulfoxide solvate, C12H14ClN4+·C6H2N3O7,·C2H6OS, (II), the 2-amino-4,6-dimethoxypyrimidine and PMN cations are protonated at one of the pyrimidine N atoms. The picrate anion interacts with the protonated cations through bifurcated N,H...O hydrogen bonds, forming R21(6) and R12(6) ring motifs. In (I), Z, = 2. In (II), two inversion-related PMN cations are connected through a pair of N,H...N hydrogen bonds involving the 4-amino group and the uncharged N atom of the pyrimidine ring, forming a cyclic hydrogen-bonded R22(8) motif. In addition to the pairing, the O atom of the dimethyl sulfoxide solvent molecule bridges the 2-amino and 4-amino groups on both sides of the paired bases, resulting in a self-complementary ,DADA, array of quadruple hydrogen-bonding patterns. [source] Hydrogen-bonded supramolecular motifs in the 1:1 monohydrated molecular adduct of acetoguanaminium chloride with acetoguanamine and in 2,4,6-triaminopyrimidinediium dichloride dihydrateACTA CRYSTALLOGRAPHICA SECTION C, Issue 11 2007Gustavo Portalone In the 1:1 monohydrated molecular adduct 2,4-diamino-6-methyl-1,3,5-triazin-1-ium chloride 2,4-diamino-6-methyl-1,3,5-triazine monohydrate, C4H8N5+·Cl,·C4H7N5·H2O, formed between 2,4-diamino-6-methyl-1,3,5-triazin-1-ium chloride (acetoguanaminium chloride) and 2,4-diamino-6-methyl-1,3,5-triazine (acetoguanamine), and in triaminopyrimidinediium dichloride dihydrate, C4H9N52+·2Cl,·2H2O, whose cationic component lies across a twofold rotation axis, the protonation occurs at the ring N atoms and the bond distances in the protonated molecules indicate significant bond alterations, consistent with charge-separated polar forms. The supramolecular structures of both compounds are stabilized by systems of hydrogen bonds forming complex sheets, interlinked by sets of hydrogen bonds involving the solvent water molecules and the chloride anions. [source] Hydrogen-bonded supramolecular motifs in 2-amino-4,6-dimethoxypyrimidinium 4-hydroxybenzoate monohydrate, 2-amino-4,6-dimethoxypyrimidinium 6-carboxypyridine-2-carboxylate monohydrate and 2-amino-4,6-dimethoxypyrimidinium hydrogen (2R,3R)-tartrate 2-amino-4,6-dimethoxypyrimidineACTA CRYSTALLOGRAPHICA SECTION C, Issue 5 2007Kaliyaperumal Thanigaimani In the crystal structures of the title compounds, C6H10N3O2+·C7H5O3,·H2O, (I), C6H10N3O2+·C7H4NO4,·H2O, (II), and C6H10N3O2+·C4H5O6,·C6H9N3O2, (III), the 2-amino-4,6-dimethoxypyrimidinium cation [abbreviated as (MeO)2 -Hampy+] interacts with the carboxylate group of the corresponding anion through a pair of nearly parallel N,H...O hydrogen bonds to form R22(8) ring motifs. In (I), the (MeO)2 -Hampy+ cation is centrosymmetrically paired through a pair of N,H...N hydrogen bonds involving the 2-amino group and a ring N atom forming an R22(8) motif. In (II), inversion-related R22(8) motifs (amino,pyrimidine,carboxylate motifs) are further bridged by N,H...O hydrogen bonds on either side forming a DDAA array of quadruple hydrogen bonds. This array is extended further on either side by Owater,H...Omethoxy hydrogen bonds, resulting in an array of six hydrogen bonds (ADDAAD). The water molecule plays a pivotal role, and five hydrogen-bonded fused rings are formed around the water molecule. In (III), the carboxy group of the tartrate anion interacts with the ring N atom and 2-amino group of the neutral (MeO)2 -ampy molecule through N,H...O and O,H...N hydrogen bonds. There is also an intramolecular O,H...O hydrogen bond in the tartrate anion. In all three crystal structures, C,H...O hydrogen bonds are observed. [source] | ||||||||||