Reinvestigation of tricyclic acyclovir: characterization of a `proton-wire' model

2013 ◽  
Vol 69 (9) ◽  
pp. 1077-1080 ◽  
Author(s):  
Montha Meepripruk ◽  
Kenneth J. Haller
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Three Dimensional ◽  
Gramicidin A ◽  
Strong Hydrogen Bond ◽  
Water Molecules ◽  
Asymmetric Unit ◽  
Acta Cryst ◽  
Dimensional Network

The crystal structure of a dihydrate of the title compound, 3-[(2-hydroxyethoxy)methyl]-6-methyl-3H-imidazolo[1,2-a]-purin-9(5H)-one, C11H13N5O3·2H2O, has been reinvestigated. The asymmetric unit contains two molecules of tricyclic acyclovir and four molecules of water. The structure consists of a three-dimensional network of strong hydrogen bonds that integrates all of the components. While the crystal structure and the formation of an (H2O)8solvent water molecule cluster through a disordered strong hydrogen bond [O...O = 2.807 (3) Å] between two water molecules across an inversion centre has been described previously [Suwińska, Golankiewicz & Zielenkiewicz (2001).Acta Cryst.C57, 767–769], the disorder was incompletely modelled. In this work, the disorder model is extended and includes disorder of one tricyclic acyclovir hydroxy group across another inversion centre [O...O = 2.644 (4) Å]. The resulting infinite O—H...O hydrogen-bonded water–hydroxy chains, analogous to the `proton wires' found in the membrane protein gramicidin A, are discussed and an unusual disorder model involving infinite concerted chains of O—H...O hydrogen bonds is provided.

scholarly journals Crystal structure of melaminium cyanoacetate monohydrate

2020 ◽  
Vol 76 (10) ◽  
pp. 1645-1648
Author(s):  
Bhawani Sigdel Regmi ◽  
Allen Apblett ◽  
Douglas Powell
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Water Molecule ◽  
Title Compound ◽  
Three Dimensional ◽  
Membered Ring ◽  
Water Molecules ◽  
Asymmetric Unit ◽  
Dimensional Network

The asymmetric unit of the title compound, 2,4,6-triamino-1,3,5-triazin-1-ium cyanoacetate monohydrate, C3H7N6 +·NCCH2COO−·H2O, consists of a melaminium cation, a cyanoacetate anion and a water molecule, which are connected to each other via N—H...O and O—H...O hydrogen bonds, generating an eight-membered ring. In the crystal, the melaminium cations are connected by two pairs of N—H...N hydrogen bonds, forming tapes along [110]. These tapes develop a three-dimensional network through N—H...O, O—H...O, N—H...N and C—H...O hydrogen bonds between the cations, anions and water molecules.

scholarly journals Crystal structure of poly[diaqua(μ2-benzene-1,4-dicarboxylato-κ2O1:O4)(μ2-benzene-1,4-dicarboxylato-κ4O1,O1′:O4,O4′)bis(μ2-3,3′,5,5′-tetramethyl-4,4′-bipyrazole-κ2N:N′)dinickel(II)]

2015 ◽  
Vol 71 (6) ◽  
pp. m127-m128
Author(s):  
Chao Wu ◽  
Peng Cao
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Water Molecule ◽  
Crystal Packing ◽  
Three Dimensional ◽  
The Other ◽  
Water Molecules ◽  
Inversion Symmetry ◽  
Asymmetric Unit ◽  
Dimensional Network

The asymmetric unit of the polymeric title compound, [Ni(C8H4O4)(C10H14N4)(H2O)]n, contains one Ni2+cation, one coordinating water molecule, one 3,3′,5,5′-tetramethyl-4,4′-bipyrazole ligand and half each of two benzene-1,4-dicarboxylate anions, the other halves being generated by inversion symmetry. The Ni2+cation exhibits an octahedral N2O4coordination sphere defined by the O atoms of the water molecule and two different anions and the N atoms of two symmetry-relatedN-heterocycles. TheN-heterocycles and both anions bridge adjacent Ni2+cations into a three-dimensional network structure, with one of the anions in a bis-bidentate and the other in a bis-monodentate bridging mode. N—H...O and O—H...O hydrogen bonds between the N-heterocycles and water molecules as donor groups and the carboxylate O atoms as acceptor groups consolidate the crystal packing.

scholarly journals Crystal structure of 3,14-diethyl-2,6,13,17-tetraazoniatricyclo[16.4.0.07,12]docosane tetrachloride tetrahydrate from synchrotron X-ray data

2021 ◽  
Vol 77 (2) ◽  
pp. 213-216
Author(s):  
Dohyun Moon ◽  
Jong-Ha Choi
Keyword(s):  
Crystal Structure ◽  
Synchrotron Radiation ◽  
Hydrogen Bonds ◽  
Three Dimensional ◽  
Water Molecules ◽  
Inversion Symmetry ◽  
Asymmetric Unit ◽  
Intermolecular Hydrogen Bonds ◽  
X Ray ◽  
Dimensional Network

The crystal structure of the hydrated title salt, C22H48N4 4+·4Cl−·4H2O (C22H48N4 = H4 L = 3,14-diethyl-2,6,13,17-tetraazoniatricyclo[16.4.0.07,12]docosane), has been determined using synchrotron radiation at 220 K. The structure determination reveals that protonation has occurred at all four amine N atoms. The asymmetric unit comprises one half of the macrocyclic cation (completed by crystallographic inversion symmetry), two chloride anions and two water molecules. The macrocyclic ring of the tetracation adopts an exodentate (3,4,3,4)-D conformation. The crystal structure is stabilized by intermolecular hydrogen bonds involving the macrocycle N—H groups and water O—H groups as donors, and the O atoms of the water molecules and chloride anions as acceptors, giving rise to a three-dimensional network.

scholarly journals Synthesis and crystal structure of catena-poly[[bis[(2,2′;6′,2′′-terpyridine)manganese(II)]-μ4-pentathiodiantimonato] tetrahydrate] showing a 1D MnSbS network

2020 ◽  
Vol 76 (1) ◽  
pp. 32-37 ◽  
Author(s):  
Felix Danker ◽  
Christian Näther ◽  
Wolfgang Bensch
Keyword(s):  
Crystal Structure ◽  
Three Dimensional ◽  
Water Molecules ◽  
Asymmetric Unit ◽  
Acta Cryst ◽  
Synthesis And Crystal Structure ◽  
Solvent Water ◽  
Dimensional Network ◽  
Terpyridine Ligands ◽  
Using Data

The asymmetric unit of the title compound, {[Mn2Sb2S5(C15H11N3)2]·4H2O} n , consists of two crystallographically independent MnII ions, two unique terpyridine ligands, one [Sb2S5]4− anion and four solvent water molecules, all of which are located in general positions. The [Sb2S5]4− anion consists of two SbS3 units that share common corners. Each of the MnII ions is fivefold coordinated by two symmetry-related S atoms of [Sb2S5]4− anions and three N atoms of a terpyridine ligand within an irregular coordination. Each two anions are linked by two [Mn(terpyridine)]2+ cations into chains along the c-axis direction that consist of eight-membered Mn2Sb2S4 rings. These chains are further connected into a three-dimensional network by intermolecular O—H...O and O—H...S hydrogen bonds. The crystal investigated was twinned and therefore, a twin refinement using data in HKLF-5 [Sheldrick (2015). Acta Cryst. C71, 3–8] format was performed.

scholarly journals Crystal structure of triaqua(2,6-dimethylpyrazine-κN4)bis(thiocyanato-κN)manganese(II) 2,5-dimethylpyrazine disolvate

2015 ◽  
Vol 71 (12) ◽  
pp. m223-m224 ◽  
Author(s):  
Stefan Suckert ◽  
Susanne Wöhlert ◽  
Inke Jess ◽  
Christian Näther
Keyword(s):  
Crystal Structure ◽  
Rotation Axis ◽  
Complex Molecule ◽  
Three Dimensional ◽  
Water Molecules ◽  
Asymmetric Unit ◽  
Acta Cryst ◽  
Dimensional Network ◽  
Entire Complex ◽  
Solvent Molecules

In the crystal structure of the title complex, [Mn(NCS)2(C6H8N2)(H2O)3]·2C6H8N2, the MnIIcation is coordinated by two terminallyN-bonded thiocyanate anions, three water molecules and one 2,6-dimethylpyrazine ligand within a slightly distorted N3O3octahedral geometry; the entire complex molecule is generated by the application of a twofold rotation axis. The asymmetric unit also contains an uncoordinating 2,5-dimethylpyrazine ligand in a general position. Obviously, the coordination to the 2,6-dimethylpyrazine ligand is preferred because coordination to the 2,5-dimethylpyrazine is hindered due to the bulky methyl group proximate to the N atom. The discrete complexes are linked by water-O—H...N(2,6-dimethylpyzazine/2,5-dimethylpyzazine) hydrogen bonding, forming a three-dimensional network. In the crystal, molecules are arranged in a way that cavities are formed in which unspecified, disordered solvent molecules reside. These were modelled employing the SQUEEZE routine inPLATON[Spek (2015).Acta Cryst. C71, 9–18]. The composition of the unit cell does not take into account the presence of the unspecified solvent.

scholarly journals Crystal structure of diaquabis(4-cyanopyridine-κN)bis(thiocyanato-κN)iron(II) 4-cyanopyridine disolvate

2017 ◽  
Vol 73 (4) ◽  
pp. 463-466 ◽  
Author(s):  
Aleksej Jochim ◽  
Inke Jess ◽  
Christian Näther
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Water Molecule ◽  
Coordination Polyhedron ◽  
Title Compound ◽  
Three Dimensional ◽  
Water Molecules ◽  
Asymmetric Unit ◽  
Dimensional Network ◽  
Solvent Molecules

The asymmetric unit of the title compound, [Fe(NCS)2(C6H4N2)2(H2O)2]·2C6H4N2, comprises one FeIIcation occupying an inversion centre as well as one thiocyanate anion, one water molecule and two 4-cyanopyridine molecules in general positions. The iron cations are coordinated by two N-bonded thiocyanate anions, two (pyridine)N-bonded 4-cyanopyridine ligands and two water molecules into discrete complexes. The resulting coordination polyhedron can be described as a slightly distorted octahedron. The discrete complexes are connected through centrosymmetric pairs of (pyridine)C—H...N(cyano) hydrogen bonds into chains that are further linked into a three-dimensional network through intermolecular O—H...N hydrogen bonds involving the 4-cyanopyridine solvent molecules.

scholarly journals Crystal structure of a second triclinic polymorph of 2-methylpyridinium picrate

2015 ◽  
Vol 71 (11) ◽  
pp. o848-o849
Author(s):  
Jeganathan Gomathi ◽  
Doraisamyraja Kalaivani
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Title Compound ◽  
Three Dimensional ◽  
Asymmetric Unit ◽  
Acta Cryst ◽  
Dimensional Network ◽  
Centroid Distance ◽  
Graph Set ◽  
Molecular Salt

The title molecular salt, C6H8N+·C6H2N3O7−(systematic name: 2-methylpyridinium 2,4,6-trinitrophenolate), crystallizes with two cations and two anions in the asymmetric unit. In the crystal, the cations are linked to the anionsviabifurcated N—H...(O,O) hydrogen bonds, generatingR12(6) graph-set motifs. Numerous C—H...O hydrogen bonds are observed between these cation–anion pairs, which result in a three-dimensional network. In addition, weak aromatic π–π stacking between the 2-methylpyridinium rings [inter-centroid distance = 3.8334 (19) Å] and very weak stacking [inter-centroid distance = 4.0281 (16) Å] between inversion-related pairs of picrate anions is observed. The title salt is a second triclinic polymorph of the structure (also withZ′ = 2) reported earlier [Anitaet al.(2006).Acta Cryst.C62, o567–o570; Chanet al.(2014).CrystEngComm,16, 4508–4538]. In the title compound, the cations and anions display a chequerboard arrangement when viewed down [100], whereas in the first polymorph, (010) layers of alternating cations and anions are apparent in a [100] view. It is interesting that the unit-cell lengths are almost identical for the two polymorphs, although the inter-axial angles are quite different.

scholarly journals 1-(4-Hydroxyphenyl)piperazine-1,4-diium tetrachloridocobalt(II) monohydrate

2014 ◽  
Vol 70 (2) ◽  
pp. m75-m75 ◽  
Author(s):  
Marwa Mghandef ◽  
Habib Boughzala
Keyword(s):  
Hydrogen Bonds ◽  
Water Molecule ◽  
Three Dimensional ◽  
Organic Cations ◽  
Water Molecules ◽  
Asymmetric Unit ◽  
Hybrid Compound ◽  
Organic Hybrid ◽  
Compound C ◽  
Dimensional Network

The asymmetric unit of the title inorganic–organic hybrid compound, (C10H16N2O)[CoCl4]·H2O, consists of a tetrahedral [CoCl4]2−anion, together with a [C10H18N2O]2+cation and a water molecule. Crystal cohesion is achieved through N—H...Cl, O—H...Cl and N—H...O hydrogen bonds between organic cations, inorganic anions and the water molecules, building up a three-dimensional network.

scholarly journals Crystal structure of poly[diaquabis(μ5-benzene-1,3-dicarboxylato)(N,N-dimethylformamide)cadmium(II)disodium(I)]

2017 ◽  
Vol 73 (11) ◽  
pp. 1599-1602 ◽  
Author(s):  
Matimon Sangsawang ◽  
Kittipong Chainok ◽  
Nanthawat Wannarit
Keyword(s):  
Crystal Structure ◽  
Coordination Polymer ◽  
Hydrogen Bonds ◽  
Three Dimensional ◽  
Water Molecules ◽  
Asymmetric Unit ◽  
Carboxylate Groups ◽  
Benzene Rings ◽  
Coordinated Water ◽  
Coordinate Geometry

The title compound, [CdNa2(C8H4O4)2(C3H7NO)(H2O)2]nor [CdNa2(1,3-bdc)2(DMF)(H2O)2]n, is a new CdII–NaIheterobimetallic coordination polymer. The asymmetric unit consists of one CdIIatom, two NaIatoms, two 1,3-bdc ligands, two coordinated water molecules and one coordinated DMF molecule. The CdIIatom exhibits a seven-coordinate geometry, while the NaIatoms can be considered to be pentacoordinate. The metal ions and their symmetry-related equivalents are connectedviachelating–bridging carboxylate groups of the 1,3-bdc ligands to generate a three-dimensional framework. In the crystal, there are classical O—H...O hydrogen bonds involving the coordinated water molecules and the 1,3-bdc carboxylate groups and π–π stacking between the benzene rings of the 1,3-bdc ligands present within the frameworks.

scholarly journals Crystal structure and hydrogen bonding in the water-stabilized proton-transfer salt brucinium 4-aminophenylarsonate tetrahydrate

2016 ◽  
Vol 72 (5) ◽  
pp. 751-755 ◽  
Author(s):  
Graham Smith ◽  
Urs D. Wermuth
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Proton Transfer ◽  
Network Structure ◽  
Three Dimensional ◽  
Water Molecules ◽  
Arsanilic Acid ◽  
Dimensional Network

In the structure of the brucinium salt of 4-aminophenylarsonic acid (p-arsanilic acid), systematically 2,3-dimethoxy-10-oxostrychnidinium 4-aminophenylarsonate tetrahydrate, (C23H27N2O4)[As(C6H7N)O2(OH)]·4H2O, the brucinium cations form the characteristic undulating and overlapping head-to-tail layered brucine substructures packed along [010]. The arsanilate anions and the water molecules of solvation are accommodated between the layers and are linked to them through a primary cation N—H...O(anion) hydrogen bond, as well as through water O—H...O hydrogen bonds to brucinium and arsanilate ions as well as bridging water O-atom acceptors, giving an overall three-dimensional network structure.

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