scholarly journals Crystal structure of pentakis(ethylenediamine-κ2N,N′)lanthanum(III) trichloride–ethylenediamine–dichloromethane (1/1/1)

2014 ◽  
Vol 70 (11) ◽  
pp. 424-426 ◽  
Author(s):  
Hope T. Sartain ◽  
Richard J. Staples ◽  
Shannon M. Biros
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Electron Density ◽  
Inversion Center ◽  
Asymmetric Unit ◽  
Acta Cryst ◽  
Bypass Procedure ◽  
Hydrogen Bonding Network ◽  
Additional Hydrogen

We report here the crystal structure of a ten-coordinate lanthanum(III) metal coordinated by five bidentate ethylenediamine ligands, [La(C2H8N2)5]Cl3·C2H8N2·CH2Cl2. One free ethylenediamine molecule and three Cl−anions are also located in the asymmetric unit. The overall structure is held together by an extensive hydrogen-bonding network between the Cl−anions and the NH groups on the metal-bound ethylenediamine ligands. The free ethylenediamine molecule is held in an ordered position by additional hydrogen bonds involving both the chlorides and –NH groups on the metal-bound ligands. One highly disordered molecule of dichloromethane is located on an inversion center; however, all attempts to model this disorder were unsuccessful. The electron density in this space was removed using the BYPASS procedure [van der Sluis & Spek (1990).Acta Cryst.A46, 194–201].

scholarly journals Crystal structure of bis{1-[(E)-(2-methoxyphenyl)diazenyl]naphthalen-2-olato-κ3O,N2,O′}copper(II) containing an unknown solvate

2015 ◽  
Vol 71 (11) ◽  
pp. m207-m208 ◽  
Author(s):  
Souheyla Chetioui ◽  
Noudjoud Hamdouni ◽  
Djamil-Azzeddine Rouag ◽  
Salah Eddine Bouaoud ◽  
Hocine Merazig
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Electron Density ◽  
Title Complex ◽  
Unit Cell ◽  
Asymmetric Unit ◽  
Acta Cryst ◽  
Coordination Environment ◽  
Independent Molecules ◽  
Solvent Molecules

The title complex, [Cu(C17H13N2O2)2], crystallizes with two independent molecules in the asymmetric unit. Each CuIIatom has a distorted ocahedral coordination environment defined by two N atoms and four O atoms from two tridentate 1-[(E)-(2-methoxyphenyl)diazenyl]naphthalen-2-olate ligands. In the crystal, the two molecules are linkedviaweak C—H...O hydrogen bonds which in turn stack parallel to [010]. A region of disordered electron density, most probably disordered methanol solvent molecules, was corrected for using the SQUEEZE routine inPLATON[Spek (2015).Acta Cryst.C71, 9–18]. Their formula mass and unit-cell characteristics were not taken into account during refinement.

scholarly journals Crystal structures of three lead(II) acetate-bridged diaminobenzene coordination polymers

2014 ◽  
Vol 70 (12) ◽  
pp. 566-572 ◽  
Author(s):  
David K. Geiger ◽  
Dylan E. Parsons ◽  
Patricia L. Zick
Keyword(s):  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Coordination Polymers ◽  
Inversion Center ◽  
Asymmetric Unit ◽  
Polymeric Chains ◽  
Coordination Spheres ◽  
Cyano Groups ◽  
Polymeric Structures ◽  
Additional Hydrogen

Poly[tris(acetato-κ2O,O′)(μ2-acetato-κ3O,O′:O)tetrakis(μ3-acetato-κ4O,O′:O:O′)bis(benzene-1,2-diamine-κN)tetralead(II)], [Pb4(CH3COO)8(C6H8N2)2]n, (I), poly[(acetato-κ2O,O′)(μ3-acetato-κ4O,O′:O:O′)(4-chlorobenzene-1,2-diamine-κN)lead(II)], [Pb(CH3COO)2(C6H7ClN2)]n, (II), and poly[(κ2O,O′)(μ3-acetato-κ4O,O′:O:O′)(3,4-diaminobenzonitrile-κN)lead(II)], [Pb(CH3COO)2(C7H7N3)]n, (III), have polymeric structures in which monomeric units are joined by bridging acetate ligands. All of the PbIIions exhibit hemidirected coordination. The repeating unit in (I) is composed of four PbIIions having O6, O6N, O7and O6N coordination spheres, respectively, where N represents a monodentate benzene-1,2-diamine ligand and O acetate O atoms. Chains along [010] are joined by bridging acetate ligands to form planes parallel to (10-1). (II) and (III) are isotypic and have one PbIIion in the asymmetric unit that has an O6N coordination sphere. Pb2O2units result from a symmetry-imposed inversion center. Polymeric chains parallel to [100] exhibit hydrogen bonding between the amine and acetate ligands. In (III), additional hydrogen bonds between cyano groups and non-coordinating amines join the chains by formingR22(14) rings.

scholarly journals Crystal structure of 1,2-bis[(1H-imidazol-2-yl)methylidene]hydrazine and its one-dimensional hydrogen-bonding network

2016 ◽  
Vol 72 (4) ◽  
pp. 556-558
Author(s):  
Chia-Hwa Lee ◽  
Gene-Hsiang Lee
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Title Compound ◽  
Inversion Center ◽  
Single Bond ◽  
One Dimensional ◽  
Axis Direction ◽  
Compound C ◽  
Hydrogen Bonding Network

In the title compound, C8H8N6, two imidazolyl groups are separated by a zigzag –CH=N—N=CH– linkage. An inversion center is located at the mid-point of the N—N single bond and the complete molecule is generated by symmetry. In the crystal, each molecule forms four N—H...N hydrogen bonds with two neighbouring molecules to constitute a one-dimensional ladder-like structure propagating along thea-axis direction.

The effect of partial methylation of the glycine amino group on crystal structure inN,N-dimethylglycine and its hemihydrate

2012 ◽  
Vol 68 (8) ◽  
pp. o283-o287 ◽  
Author(s):  
Vasily S. Minkov ◽  
Elena V. Boldyreva
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Water Molecules ◽  
Amino Group ◽  
Asymmetric Unit ◽  
Partial Methylation ◽  
Space Groups ◽  
Carboxylate Groups ◽  
Anhydrous Compound ◽  
Additional Hydrogen

N,N-Dimethylglycine, C4H9NO2, and its hemihydrate, C4H9NO2·0.5H2O, are discussed in order to follow the effect of the methylation of the glycine amino group (and thus its ability to form several hydrogen bonds) on crystal structure, in particular on the possibility of the formation of hydrogen-bonded `head-to-tail' chains, which are typical for the crystal structures of amino acids and essential for considering amino acid crystals as mimics of peptide chains. Both compounds crystallize in centrosymmetric space groups (PbcaandC2/c, respectively) and have twoN,N-dimethylglycine zwitterions in the asymmetric unit. In the anhydrous compound, there are no head-to-tail chains but the zwitterions formR44(20) ring motifs, which are not bonded to each other by any hydrogen bonds. In contrast, in the crystal structure ofN,N-dimethylglycinium hemihydrate, the zwitterions are linked to each other by N—H...O hydrogen bonds into infiniteC22(10) head-to-tail chains, while the water molecules outside the chains provide additional hydrogen bonds to the carboxylate groups.

scholarly journals Crystal structure of a trigonal polymorph of aquadioxidobis(pentane-2,4-dionato-κ2 O,O′)uranium(VI)

2022 ◽  
Vol 78 (1) ◽  
Author(s):  
Alejandro Hernandez ◽  
Indranil Chakraborty ◽  
Gabriela Ortega ◽  
Christopher J. Dares
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Water Molecule ◽  
Equatorial Plane ◽  
Title Compound ◽  
Uranium Atom ◽  
Intermolecular Hydrogen Bonding ◽  
Two Dimensional ◽  
Asymmetric Unit ◽  
Acta Cryst

The title compound, [UO2(acac)2(H2O)] consists of a uranyl(VI) unit ([O=U=O]2+) coordinated to two monoanionic acetylacetonate (acac, C5H7O2) ligands and one water molecule. The asymmetric unit includes a one-half of a uranium atom, one oxido ion, one-half of a water molecule and one acac ligand. The coordination about the uranium atom is distorted pentagonal–bipyramidal. The acac ligands and Ow atom comprise the equatorial plane, while the uranyl O atoms occupy the axial positions. Intermolecular hydrogen bonding between complexes results in the formation of two-dimensional hexagonal void channels along the c-axis direction with a diameter of 6.7 Å. The monoclinic (P21/c space group) polymorph was reported by Alcock & Flanders [(1987). Acta Cryst. C43, 1480–1483].

scholarly journals Bis(μ2-4-nitrophenolato)bis(4-nitrophenolato)di-μ3-oxido-octaphenyltetratin chloroform sesquisolvate [+ solvate]: a tetranuclear stannoxane

IUCrData ◽  
2019 ◽  
Vol 4 (8) ◽  
Author(s):  
Patrick Butler
Keyword(s):  
Hydrogen Bonds ◽  
Electron Density ◽  
Three Dimensional ◽  
The Other ◽  
Dimensional Structure ◽  
Coordination Geometry ◽  
Asymmetric Unit ◽  
Acta Cryst ◽  
Complex Molecules ◽  
Three Dimensional Structure

The title tetranuclear stannoxane, [Sn4(C6H5)8(C6H4NO3)4O2]·1.5CHCl3·solvent, crystallized with two independent complex molecules, A and B, in the asymmetric unit together with 1.5 molecules of chloroform. There is also a region of disordered electron density, which was corrected for using the SQUEEZE routine [Spek (2015). Acta Cryst. C71, 9–18]. The oxo-tin core of each complex is in a planar `ladder' arrangement and each Sn atom is fivefold SnO3C2 coordinated, with one tin centre having an almost perfect square-pyramidal coordination geometry, while the other three Sn centres have distorted shapes. In the crystal, the complex molecules are arranged in layers, composed of A or B complexes, lying parallel to the bc plane. The complex molecules are linked by a number of C—H...O hydrogen bonds within the layers and between the layers, forming a supramolecular three-dimensional structure.

scholarly journals A substrate selected by phage display exhibits enhanced side-chain hydrogen bonding to HIV-1 protease

2018 ◽  
Vol 74 (7) ◽  
pp. 690-694 ◽  
Author(s):  
Ian W. Windsor ◽  
Ronald T. Raines
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Molecular Recognition ◽  
Hydrogen Bonds ◽  
Phage Display ◽  
Directed Evolution ◽  
Side Chain ◽  
Endogenous Substrates ◽  
Hiv 1 ◽  
Additional Hydrogen

Crystal structures of inactive variants of HIV-1 protease bound to peptides have revealed how the enzyme recognizes its endogenous substrates. The best of the known substrates is, however, a nonnatural substrate that was identified by directed evolution. The crystal structure of the complex between this substrate and the D25N variant of the protease is reported at a resolution of 1.1 Å. The structure has several unprecedented features, especially the formation of additional hydrogen bonds between the enzyme and the substrate. This work expands the understanding of molecular recognition by HIV-1 protease and informs the design of new substrates and inhibitors.

scholarly journals Crystal structure ofN,N′-dibenzyl-3,3′-dimethoxybenzidine

2018 ◽  
Vol 74 (3) ◽  
pp. 271-274
Author(s):  
Hansu Im ◽  
Jineun Kim ◽  
Changeun Sim ◽  
Tae Ho Kim
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Schiff Base ◽  
Hydrogen Bonds ◽  
Dft Calculations ◽  
Title Compound ◽  
Condensation Reaction ◽  
Asymmetric Unit ◽  
One Dimensional ◽  
Acidic Conditions

The title compound, (systematic name:N,N′-dibenzyl-3,3′-dimethoxy-1,1′-biphenyl-4,4′-diamine), C28H28N2O2, was synthesized by the reduction of a Schiff base preparedviaa condensation reaction betweeno-dianisidine and benzaldehyde under acidic conditions. The molecule lies on a crystallographic inversion centre so that the asymmetric unit contains one half-molecule. The biphenyl moiety compound is essentially planar. Two intramolecular N—H...O hydrogen bonds occur. The dihedral angle between the terminal phenyl and phenylene rings of a benzidine unit is 48.68 (6)°. The methylene C atom of the benzyl group is disordered over two sets of sites, with occupancy ratio 0.779 (18):0.221 (18). In the crystal, molecules are connected by hydrogen bonding betweeno-dianisidine O atoms and H atoms of the terminal benzyl groups, forming a one-dimensional ladder-like structure. In the data from DFT calculations, the central biphenyl showed a twisted conformation.

scholarly journals Hydrogen bonding in the crystal structure of the molecular salt of pyrazole–pyrazolium picrate

2016 ◽  
Vol 72 (6) ◽  
pp. 861-863 ◽  
Author(s):  
Ping Su ◽  
Xue-gang Song ◽  
Ren-qiang Sun ◽  
Xing-man Xu
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Organic Salt ◽  
Asymmetric Unit ◽  
Molecular Salt ◽  
Hydrogen Bonded

The asymmetric unit of the title organic salt [systematic name: 1H-pyrazol-2-ium 2,4,6-trinitrophenolate–1H-pyrazole (1/1)], H(C3H4N2)2+·C6H2N3O7−, consists of one picrate anion and one hydrogen-bonded dimer of a pyrazolium monocation. The H atom involved in the dimer N—H...N hydrogen bond is disordered over both symmetry-unique pyrazole molecules with occupancies of 0.52 (5) and 0.48 (5). In the crystal, the component ions are linked into chains along [100] by two different bifurcated N—H...(O,O) hydrogen bonds. In addition, weak C—H...O hydrogen bonds link inversion-related chains, forming columns along [100].

scholarly journals 2,2′-(Piperazine-1,4-diyl)diethanaminium dibenzoate

2012 ◽  
Vol 68 (8) ◽  
pp. o2389-o2389
Author(s):  
Ignacy Cukrowski ◽  
Adedapo S. Adeyinka ◽  
David C. Liles
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Intermolecular Interactions ◽  
Two Dimensional ◽  
Asymmetric Unit ◽  
Acta Cryst ◽  
Two Component ◽  
Anions And Cations ◽  
Benzoate Anion

The asymmetric unit of the title salt C8H22N42+·2C7H5O2−, comprises two independent pairs of half a 2,2′-(piperazine-1,4-diyl)diethanaminium dication plus a benzoate anion. The dications are symmetrical and lie across crystallographic centres of inversion. The crystal structure was refined as a two-component pseudo-merohedral twin using the twin law 001 0-10 100 [he domain fractions are 0.8645 (8) and 0.1355 (8)]. The anions and cations are linked by N—H...O hydrogen bonds and weak N—H...O intermolecular interactions to form infinite two-dimensional networks parallel to [101]. The conformation adopted by the cation in the crystal structure is very similar to that adopted by the same cation in the structures of the 2-hydroxybenzoate [Cukrowskiet al.(2012).Acta Cryst, E68, o2387], the nitrate and the tetrahydrogen pentaborate salts.

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