Anomeric effect for a 2,5,7-triazabicyclo[2.2.1]heptane derivative

2009 ◽  
Vol 65 (3) ◽  
pp. o115-o117 ◽  
Author(s):  
Amir Taheri ◽  
Sayed Mojtaba Moosavi
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Bond Length ◽  
Anomeric Effect ◽  
First Time ◽  
Anomeric Effects

A new member of the polyazapolycyclic family of compounds, namelyN3,N6,2,5,7-pentaphenyl-2,5,7-triazabicyclo[2.2.1]heptane-3,6-diamine xylene solvate, C34H31N5·C8H10, was synthesized for the first time and the crystal structure is reported. There are no hydrogen bonds joining the molecules. All four chiral C atoms have the same absolute configurations. With regard to the four N—C—N groups, anomeric effects are observed to cause a reduction of C—N bond length and N-atom pyramidality.

scholarly journals Crystal structure of 4-(dimethylamino)pyridiniumcis-diaquabis(oxalato-κ2O,O′)ferrate(III) hemihydrate

2015 ◽  
Vol 71 (8) ◽  
pp. 934-936 ◽  
Author(s):  
Edith Dimitri Djomo ◽  
Frédéric Capet ◽  
Justin Nenwa ◽  
Michel M. Bélombé ◽  
Michel Foulon
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Bond Length ◽  
Three Dimensional ◽  
Coordination Environment ◽  
Distorted Octahedral Coordination ◽  
Dimensional Network ◽  
Distorted Octahedral ◽  
Ionic Components ◽  
Distorted Octahedral Coordination Environment

The FeIIIions in the hybrid title salt, (C7H11N2)[Fe(C2O4)2(H2O)2]·0.5H2O, show a distorted octahedral coordination environment, with four O atoms from two chelating oxalate dianions and two O atoms from twocisaqua ligands. The average Fe—O(oxalate) bond length [2.00 (2) Å] is shorter than the average Fe—O(water) bond length [2.027 (19) Å]. The ionic components are connectedviaintermolecular N—H...O and O—H...O hydrogen bonds into a three-dimensional network.

Synthesis and crystal structure of 2-isocyano-4-methylphenyl diphenylacetate: a rare case of an easily accessible odourless isocyanide

2015 ◽  
Vol 71 (2) ◽  
pp. 155-158 ◽  
Author(s):  
Dina Boyarskaya ◽  
Margarita Avdontceva ◽  
Tatiana Chulkova
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Bond Length ◽  
Triple Bond ◽  
Rare Case ◽  
Synthesis And Crystal Structure ◽  
Space Group ◽  
One Dimensional ◽  
Acidic Hydrogen

Acidic hydrogen containing 2-isocyano-4-methylphenyl diphenylacetate, C22H17NO2, (I), was synthesized by the base-promoted reaction between 5-methylbenzoxazole and diphenylacetyl chloride. Achiral (I) crystallizes in the chiralP212121space group. The C[triple-bond]N bond length is 1.164 (2) Å and the angle between the OCO and 2-isocyano-4-methylphenyl planes is 69.10 (16)°. Molecules are linkedviaC=O...Hphenyland bifurcated N[triple-bond]C...Hphenyl/N[triple-bond]C...Hmethinehydrogen bonds, forming one-dimensional arrays.

scholarly journals Crystal structure of acetonitrile[η6-1-methyl-4-(1-methylethyl)benzene][1-(pyrimidin-2-yl)-3H-indol-1-ium-2-yl-κ2N,C]ruthenium(II) bis(hexafluoridoantimonate)

2015 ◽  
Vol 71 (10) ◽  
pp. 1190-1192 ◽  
Author(s):  
Carina Sollert ◽  
Andreas Orthaber ◽  
Lukasz T. Pilarski
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Bond Length ◽  
Title Compound ◽  
Complex Cation ◽  
Solvent Molecule ◽  
Coordination Environment ◽  
C And N ◽  
Imine Bond

In the title compound, [Ru(C10H14)(C12H9N3)(CH3CN)][SbF6]2, the ruthenium(II) cation isη6-coordinated by thepara-cymene ligand with a Ru–centroid(η6-benzene) distance of 1.746 (2) Å. Furthermore, ruthenium coordinations to the C and N atoms of the pyrimidyl indole ligand are found to be 1.986 (4) and 2.082 (3) Å, respectively. The typical piano-stool coordination environment is saturated with an acetonitrile solvent molecule with a Ru—N distance of 2.044 (3) Å. The indolyl ligand is protonated at the C3 position with the N=C imine bond length appropriate to that of related 3H-indole-based complexes. In the crystal, the complex cation is linked to the SbF6−ions through weak C—H...F hydrogen bonds.

scholarly journals Variable-temperature neutron diffraction studies of the short, strong hydrogen bonds in the crystal structure of pyridine-3,5-dicarboxylic acid

2005 ◽  
Vol 61 (6) ◽  
pp. 724-730 ◽  
Author(s):  
John. A. Cowan ◽  
Judith A. K. Howard ◽  
Garry, J. McIntyre ◽  
Samuel M.-F Lo ◽  
Ian D. Williams
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Carboxylic Acid ◽  
Hydrogen Bonds ◽  
Neutron Diffraction ◽  
Dicarboxylic Acid ◽  
Bond Length ◽  
Variable Temperature ◽  
Temperature Dependent ◽  
Proton Migration

Pyridine-3,5-dicarboxylic acid has been studied by single-crystal neutron diffraction at 15 and 296 K. Pyridine-3,5-dicarboxylic acid, in which the carboxylic acid protons have been replaced by deuterons, has also been studied at 15, 150 and 296 K. The protonated structure contains a short N...H...O hydrogen bond [N...O 2.523 (2) Å at 15 K]. Temperature-dependent proton migration occurs where the N—H distance in the hydrogen bond changes from 1.213 (4) Å at 15 K to 1.308 (6) Å at 300 K. In the deuterated structure the overall hydrogen-bond length increased [N...O 2.538 (3) Å at 15 K] and the magnitude of the migration increased so that the N—D distance changes from 1.151 (3) Å at 15 K to 1.457 (4) Å at 300 K.

scholarly journals Crystal structure oftrans-(1,8-dibutyl-1,3,6,8,10,13-hexaazacyclotetradecane-κ4N3,N6,N10,N13)bis(perchlorato-κO)copper(II) from synchrotron data

2015 ◽  
Vol 71 (2) ◽  
pp. 136-138 ◽  
Author(s):  
Dae-Woong Kim ◽  
Jong Won Shin ◽  
Dohyun Moon
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Bond Length ◽  
Macrocyclic Ligand ◽  
Three Dimensional ◽  
Distorted Octahedral Geometry ◽  
Inversion Center ◽  
Asymmetric Unit ◽  
Dimensional Network ◽  
Distorted Octahedral

The structure of the title compound, [Cu(ClO4)2(C16H38N6)] has been determined from synchrotron data, λ = 0.62988 Å. The asymmetric unit comprises one half of the CuIIcomplex as the CuIIcation lies on an inversion center. It is coordinated by the four secondary N atoms of the macrocyclic ligand and the mutuallytransO atoms of the two perchlorate ions in a tetragonally distorted octahedral geometry. The average equatorial Cu—N bond length is significantly shorter than the average axial Cu—O bond length [2.010 (4) and 2.569 (1) Å, respectively]. Intramolecular N—H...O hydrogen bonds between the macrocyclic ligand and uncoordinating O atoms of the perchlorate ligand stabilize the molecular structure. In the crystal structure, an extensive series of intermolecular N—H...O and C—H...O hydrogen bonds generate a three-dimensional network.

scholarly journals Synthesis, FT–IR characterization and crystal structure of aqua(5,10,15,20-tetraphenylporphyrinato-κ4N)manganese(III) trifluoromethanesulfonate

2016 ◽  
Vol 72 (5) ◽  
pp. 720-723 ◽  
Author(s):  
Wafa Harhouri ◽  
Chadlia Mchiri ◽  
Shabir Najmudin ◽  
Cecilia Bonifácio ◽  
Habib Nasri
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Crystal Lattice ◽  
Bond Length ◽  
Crystal Packing ◽  
Aqua Ligand ◽  
Coordination Environment ◽  
Counter Ions ◽  
Phenyl Rings ◽  
Ft Ir

In the title salt, [Mn(C44H28N4)(H2O)](CF3SO3) or [MnIII(TPP)(H2O)](CF3SO3) (where TPP is the dianion of 5,10,15,20-tetraphenylporphyrin), the MnIIIcation is chelated by the four pyrrole N atoms of the porphyrinate anion and additionally coordinated by an aqua ligand in an apical site, completing the distorted square-pyramidal coordination environment. The average Mn—N(pyrrole) bond length is 1.998 (9) Å and the Mn—O(aqua) bond length is 2.1057 (15) Å. The central MnIIIion is displaced by 0.1575 (5) Å from the N4C20mean plane of the porphyrinate anion towards the apical aqua ligand. The porphyrinate macrocycle exhibits a moderate ruffling and strong saddle deformations. In the crystal lattice, the [MnIII(TPP)(H2O)]+cation and the trifluoromethanesulfonate counter-ions are arranged in alternating planes packed along [001]. The components are linked together through O—H...O hydrogen bonds and much weaker C—H...O and C—H...F interactions. The crystal packing is further stabilized by weak C—H...π interactions involving the pyrrole and phenyl rings of the porphyrin moieties.

Die Kristallstruktur von Bis-[methylammonium]-hexafluorosilikat, (MeNH3)2SiF6 / The Crystal Structure of Bis-[methylammonium]-hexafluorosilicate, (MeNH3)2SiF6

2002 ◽  
Vol 57 (9) ◽  
pp. 1003-1007 ◽  
Author(s):  
Jens Graulich ◽  
Dietrich Babel
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Single Crystal ◽  
Bond Length ◽  
Structure Determination ◽  
Average Bond Length ◽  
Space Group ◽  
X Ray ◽  
Average Bond

The results of a single crystal X-ray structure determination of monoclinic (MeNH3)2SiF6 are reported: a = 962.3(5), b = 964.4(1), c = 966.4(5) pm, " = 100.03(3)°; V = 883.2(7) Å3, Z = 4, space group C2/c; wR2 = 0.0999 based on F02 of 1291 independent reflections (including H refinement without restrictions). The structure is related to that of (NH4)2SiF6, but contains the dumb-bells of the cations well oriented along the greater cell diagonals and fixed by one nearly linear and two bi-furcated hydrogen bonds (N...F: 281 and 293 - 305 pm, resp.). The [SiF6]2- octahedron is nearly undistorted with average bond length Si-F: 167.7 pm (169.9 pm corrected for thermal motion)

The contribution of non-classical CHax⋯OC hydrogen bonds to the anomeric effect in fluoro and oxa-methoxycyclohexanes

2021 ◽  
Vol 23 (10) ◽  
pp. 5845-5851
Author(s):  
Bruno A. Piscelli ◽  
David O’Hagan ◽  
Rodrigo A. Cormanich
Keyword(s):  
Hydrogen Bonds ◽  
Anomeric Effect ◽  
Anomeric Effects

In this theory study the dominance of non-classical 1,3-diaxial CHax⋯OC hydrogen bonds (NCHBs) dictating anomeric effects in fluorinated methoxycyclohexanes and 2-methoxytetrahydropyrans is demonstrated, a phenomenon which is most often described as a consequence of hyperconjugation.

scholarly journals Crystal structure of diaqua[5,10,15,20-tetrakis(4-methoxyphenyl)porphyrinato-κ4N]iron(III) diaqua(18-crown-6)potassium bis(trifluoromethanesulfonate)–18-crown-6 (1/2)

2015 ◽  
Vol 71 (12) ◽  
pp. m215-m216
Author(s):  
Leila Ben Haj Hassen ◽  
Zouhour Denden ◽  
Yoann Rousselin ◽  
Habib Nasri
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Bond Length ◽  
High Spin ◽  
Title Compound ◽  
Crystal Packing ◽  
Water Molecules ◽  
Supramolecular Architecture ◽  
One Dimensional ◽  
Phenyl Rings

In the title compound, [FeIII(C48H36N4O2)(H2O)2][K(C12H24O6)(H2O)2](SO3CF3)2·2C12H24O6, the FeIIIatom is situated on an inversion centre and is octahedrally coordinated by four pyrrole N atoms of the deprotenated 5,10,15,20-tetrakis(4-methoxyphenyl)porphyrinate ligand and two water molecules. The average equatorial Fe—N(pyrrole) bond length [2.043 (6) Å] is consistent with a high-spin (S= 5/2) iron(III) metalloporphyrin derivative. The K+cation, which also lies on an inversion centre, is chelated by the six O atoms of one 18-crown-6 molecule and is additionally coordinated by two water molecules in a distorted hexagonal–bipyramidal geometry. In the crystal, the cations, anions and one non-coordinating 18-crown-6 molecule are linked by classical O—H...O hydrogen bonds and non-conventional C—H...O hydrogen bonds, leading to a one-dimensional supramolecular architecture along [10-1]. The crystal packing is further stabilized by weak C—H...π interactions involving pyrrole and phenyl rings of the porphyrins, as well as weak C—H...F contacts involving the (SO3CF3)−counter-ion and the 18-crown-6 molecules.

scholarly journals Crystal structure of dichloridobis{μ-2-methoxy-6-[(methylimino)methyl]phenolato}{2-methoxy-6-[(methylimino)methyl]phenolato}cadmium(II)cobalt(III) monohydrate

2018 ◽  
Vol 74 (11) ◽  
pp. 1532-1535 ◽  
Author(s):  
Olga Yu. Vassilyeva ◽  
Katerina V. Kasyanova ◽  
Vladimir N. Kokozay ◽  
Brian W. Skelton
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Oxygen Atom ◽  
Crystal Lattice ◽  
Bond Length ◽  
Title Compound ◽  
Water Molecules ◽  
Cell Parameters ◽  
Solvent Water ◽  
Weak Hydrogen Bonds

The title compound, [CoCd(C9H10NO2)3Cl2]·H2O, is a solvatomorph of the corresponding hemihydrate recently published by us [Nesterova et al. (2018). Appl. Cat. A, 560, 171–184]. The current structure reveals different cell parameters and space group compared with the published one while both are monoclinic with almost the same cell volume. The title compound is formed of discrete neutral dinuclear molecules with no crystallographically imposed symmetry and water molecules of crystallization. The overall geometry about the cobalt(III) ion is octahedral with an N3O3 environment; each ligand acts as a meridional ONO donor. The CdII coordination sphere approximates an irregular square pyramid with a chlorine atom at the apex. There is significant shortening of a Cd—O bond length to the oxygen atom of the methoxo group on one of the ligands [2.459 (3) Å] compared to the corresponding distance in the published structure [2.724 (7) Å], while other Cd—Cl/N/O bonds remain roughly the same. In the crystal lattice, the heterometallic molecules, which are related by the crystallographic n-glide plane and interlinked by weak hydrogen bonds to solvent water molecules, form columns along [101]. Adjacent columns lie antiparallel to each other.

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