The crystal structure of deuterated trans-Tetraamminedinitronickel(II) at 4.2 K by neutron diffraction

1981 ◽  
Vol 34 (5) ◽  
pp. 993 ◽  
Author(s):  
BN Figgis ◽  
PA Reynolds ◽  
GA Williams ◽  
N Lehner
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Neutron Diffraction ◽  
Rigid Body ◽  
Large Amplitude ◽  
Translational Motion ◽  
Axial Direction ◽  
Full Matrix ◽  
X Ray

The crystal structure of deuterated trans-tetraamminedinitronickel(II), Ni(ND3)4(NO2)2, has been determined by single-crystal neutron diffraction methods at 4·2 K. Crystals are monoclinic, C2/m, a 1058(l), b 672(1), c 586.3(3) pm, β 114.82(5)�, Z = 2. Diffractometry has provided Bragg intensities for 219 independent reflections; and the structure has been refined by full-matrix least-squares methods to R(F2) 0·070 and χ2 3·8. There are slight differences in the molecular geometries determined by neutron diffraction and earlier X-ray determinations of Ni(NH3)4(NO2)2 at 295 and 130 K. Small, but significant, decreases are evident in all non-hydrogen bond lengths on decrease in temperature from 295 to 4·2 K, up to a maximum of 2·0(4) pm for the Ni-NH3/ND3 bond. The magnitudes of these decreases are correlated with the force constants of the bonds. The intermolecular geometry and thermal parameters show that in the ab plane there is a network of relatively strong, linear N-D···O hydrogen bonds. In the c* direction there is a slightly bent, longer, N-D(1)···O bond which is weaker. This causes a large amplitude of rigid-body translational motion in the c* direction, together with high thermal motion of D(1) in the b axial direction.

The whole range of hydrogen bonds in one crystal structure: neutron diffraction and charge-density studies of N,N-dimethylbiguanidinium bis(hydrogensquarate)

2011 ◽  
Vol 67 (6) ◽  
pp. 552-559 ◽  
Author(s):  
Mihaela-Diana Şerb ◽  
Ruimin Wang ◽  
Martin Meven ◽  
Ulli Englert
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
High Resolution ◽  
Hydrogen Bonds ◽  
Neutron Diffraction ◽  
Electron Density ◽  
Organic Salt ◽  
X Ray Diffraction ◽  
Covalent Character ◽  
X Ray

N,N-Dimethylbiguanidinium bis(hydrogensquarate) features an impressive range of hydrogen bonds within the same crystal structure: neighbouring anions aggregate to a dianionic pair through two strong O—H...O interactions; one of these can be classified among the shortest hydrogen bonds ever studied. Cations and anions in this organic salt further interact via conventional N—H...O and nonclassical C—H...O contacts to an extended structure. As all these interactions occur in the same sample, the title compound is particularly suitable to monitor even subtle trends in hydrogen bonds. Neutron and high-resolution X-ray diffraction experiments have enabled us to determine the electron density precisely and to address its properties with an emphasis on the nature of the X—H...O interactions. Sensitive criteria such as the Laplacian of the electron density and energy densities in the bond-critical points reveal the incipient covalent character of the shortest O—H...O bond. These findings are in agreement with the precise geometry from neutron diffraction: the shortest hydrogen bond is also significantly more symmetric than the longer interactions.

Crystal structure of Tetracyclo[5,3,1,12,6,04,9]dodecane (iceane)

1977 ◽  
Vol 30 (8) ◽  
pp. 1837 ◽  
Author(s):  
DPG Hamon ◽  
CL Raston ◽  
GF Taylor ◽  
JN Varghese ◽  
AH White
Keyword(s):  
Crystal Structure ◽  
Rigid Body ◽  
Least Squares ◽  
Title Compound ◽  
Molecular Geometry ◽  
Thermal Motion ◽  
X Ray Diffraction ◽  
Full Matrix ◽  
X Ray ◽  
Hexagonal Close Packed

The crystal structure of the title compound, C12H18, has been determined at 295 K by X-ray diffraction and refined by full-matrix least squares to a residual of 0.049 for 216 ?observed? reflections; molecular geometry has been corrected for the effects of thermal motion using a rigid body approximation. Crystals are hexagonal, P63/m, a = 6.582(1), c = 11.843(3) Ǻ, Z = 2, the molecules occupying a hexagonal close- packed array.

scholarly journals Engineering short, strong hydrogen bonds in urea di-carboxylic acid complexes

CrystEngComm ◽  
2014 ◽  
Vol 16 (35) ◽  
pp. 8177-8184 ◽  
Author(s):  
Andrew O. F. Jones ◽  
Charlotte K. Leech ◽  
Garry J. McIntyre ◽  
Chick C. Wilson ◽  
Lynne H. Thomas
Keyword(s):  
Hydrogen Bond ◽  
Carboxylic Acid ◽  
Hydrogen Bonds ◽  
Neutron Diffraction ◽  
Structural Changes ◽  
Acid Amide ◽  
Molecular Complexes ◽  
Temperature Dependent ◽  
X Ray ◽  
Methyl Substitution

The persistence of the acid⋯amide heterodimer and the effect of methyl substitution on the short strong O–H⋯O hydrogen bond is investigated in urea and methylurea di-carboxylic acid molecular complexes. Temperature dependent structural changes are also reported utilising X-ray and neutron diffraction in tandem.

Solid-state and Calculated Electronic Structure of 4-Acetylpyrazole

2014 ◽  
Vol 69 (7) ◽  
pp. 839-843 ◽  
Author(s):  
Guido D. Frey ◽  
Wolfgang W. Schoeller ◽  
Eberhardt Herdtweck
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Electronic Structure ◽  
Solid State ◽  
Hydrogen Bonds ◽  
Single Crystal ◽  
Carbonyl Group ◽  
Monoclinic Space Group ◽  
X Ray ◽  
Ribbon Structure

The crystal structure of 1-(1H-pyrazol-4-yl)ethanone (commonly known as 4-acetylpyrazole; C5H6N2O) was determined from single-crystal X-ray data at 173 K: monoclinic, space group P21/n (no. 14), a = 3.865(1), b = 5.155(1), c = 26.105(8) Å, β = 91.13(1)°, V = 520.0(2) Å3 and Z = 4. The adjacent molecules assemble into a wave-like ribbon structure in the solid state, linked by strong intermolecular N-H...N hydrogen bonds between the pyrazole rings and a weak C-H...O=C hydrogen bond involving the carbonyl group. The ribbons are stacked in the solid state via weak π interactions between the pyrazole rings.

Two tautomers in one crystal: 4(5)-nitro-5(4)-methoxyimidazole

2004 ◽  
Vol 60 (2) ◽  
pp. 191-196 ◽  
Author(s):  
Maciej Kubicki
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Three Dimensional ◽  
Imidazole Derivative ◽  
Hydrogen Atoms ◽  
X Ray ◽  
Dimensional Network ◽  
Hydrogen Bond Pattern ◽  
Annular Tautomerism

The case of prototropic annular tautomerism in an imidazole derivative has been found. The crystal structure contains a 50:50 mixture of two tautomers: 4-nitro-5-methoxyimidazole and 5-nitro-4-methoxyimidazole. The X-ray experiment actually shows the superposition of these compounds; it appears as if the structure is centrosymmetric and the N—H hydrogen atoms are disordered over two ring N atoms. Owing to the hydrogen-bond pattern, the values of their site occupation factors have to be exactly equal to 1/2. The molecules are connected into a three-dimensional network by means of N—H...N and C—H...O hydrogen bonds.

Crystal structure of salmeterol xinafoate form I (Serevent®Diskus®), (C25H37NO4)(C11H8O3)

2015 ◽  
Vol 30 (4) ◽  
pp. 333-339 ◽  
Author(s):  
James A. Kaduk ◽  
Kai Zhong ◽  
Amy M. Gindhart ◽  
Thomas N. Blanton
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Powder Diffraction ◽  
Density Functional ◽  
Powder Diffraction Data ◽  
Powder Diffraction File ◽  
X Ray ◽  
Salmeterol Xinafoate ◽  
Structure Solution

The crystal structure of salmeterol xinafoate has been solved and refined using synchrotron X-ray powder diffraction data, and optimized using density functional techniques. Salmeterol xinafoate crystallizes in space group P−1 (#2) with a = 9.173 89(13), b = 9.483 79(14), c = 21.3666(4) Å, α = 82.2646(13), β = 85.2531(12), γ = 62.1565(11)°, V = 1628.37(5) Å3, and Z = 2. Key to the structure solution was linking the two fragments by a Li atom along the expected N–H···O hydrogen bond. The salmeterol cation and xinafoate anion are linked by N–H···O and O–H···O hydrogen bonds, interactions which cause the salmeterol to adjust its conformation. The hydrogen bonds result in complex chains along the b-axis. The powder pattern is included in the Powder Diffraction File™ as entry 00-065-1430.

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 On hydrogen bonding in 1,6-anhydro-β-D-glucopyranose (levoglucosan): X-ray and neutron diffraction and DFT study

2006 ◽  
Vol 62 (5) ◽  
pp. 912-918 ◽  
Author(s):  
Ľubomír Smrčok ◽  
Mariana Sládkovičová ◽  
Vratislav Langer ◽  
Chick C. Wilson ◽  
Miroslav Koóš
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Solid State ◽  
Hydrogen Bonds ◽  
Neutron Diffraction ◽  
Dft Calculations ◽  
Diffraction Data ◽  
Neutron Diffraction Study ◽  
Single Crystal Diffraction ◽  
X Ray

The geometry of hydrogen bonds in 1,6-anhydro-β-D-glucopyranose (levoglucosan) is accurately determined by refinement of time-of-flight neutron single-crystal diffraction data. Molecules of levoglucosan are held together by a hydrogen-bond array formed by a combination of strong O—H...O and supporting weaker C—H...O bonds. These are fully and accurately detailed by the neutron diffraction study. The strong hydrogen bonds link molecules in finite chains, with hydroxyl O atoms acting as both donors and acceptors of hydroxyl H atoms. A comparison of molecular and solid-state DFT calculations predicts red shifts of O—H and associated blue shifts of C—H stretching frequencies due to the formation of hydrogen bonds in this system.

Location of the proton in the very strong OHO hydrogen bonds in 2-(N,N-diethylamino-N-oxymethyl)-4,6-dichlorophenol. A single crystal neutron diffraction study

1997 ◽  
Vol 212 (2) ◽  
Author(s):  
H. Ptasiewicz-Bak ◽  
R. Tellgren ◽  
I. Olovsson ◽  
A. Koll
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Neutron Diffraction ◽  
Single Crystal ◽  
Diffraction Study ◽  
Neutron Diffraction Study ◽  
Crystallographic Symmetry ◽  
O 175.8 ◽  
Oxygen Atoms

AbstractThe crystal structure of 2-(N,N-diethylamino-N-oxymethyl)-4,6-dichlorophenol contains two slightly different molecules A and B, both with very strong intramolecular O … H … O hydrogen bonds, with O–O distances 2.423(4) Å and 2.400(5) Å, respectively, and with no crystallographic symmetry. The bridging oxygen atoms are also chemically different, O1 is bonded to carbon and O2 to nitrogen. The single crystal neutron diffraction study shows quite unambiguously that the proton in both cases is located slightly off-centred. In the A molecule O1–H = 1.167(6) Å, H–O2 = 1.258(6) Å and the angle O–H–O = 175.8(5)°; in the B molecule O1–H = 1.186(7) Å, H–O2 = 1.214(7) Å and the angle O–H–O = 176.5(5)°. As expected the proton is thus closer to the centre in the slightly shorter hydrogen bond.

Crystal structure of hydroxyzine dihydrochloride, C21H29ClN2O2Cl2

2018 ◽  
Vol 34 (1) ◽  
pp. 66-73
Author(s):  
Jordan A. Krueger ◽  
James A. Kaduk ◽  
Amy M. Gindhart ◽  
Thomas N. Blanton
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Powder Diffraction ◽  
Density Functional ◽  
Hydroxyl Group ◽  
Strong Hydrogen Bond ◽  
Side Chain ◽  
Powder Diffraction File ◽  
X Ray

The crystal structure of hydroxyzine dihydrochloride has been solved and refined using synchrotron X-ray powder diffraction data, and optimized using density functional techniques. Hydroxyzine dihydrochloride crystallizes in space group P21 (#4) with a = 11.48735(10), b = 7.41792(7), c = 14.99234(15) Å, β = 110.4383(10)°, V = 1197.107(13) Å3, and Z = 2. The hydroxyl-containing side chain of the cation is disordered over two conformations, with ~70/30% occupancy. The crystal structure consists of alternating polar (which includes the cation-anion interactions and hydrogen bonds) and nonpolar layers parallel to the ab-plane. The crystal structure is dominated by hydrogen bonds. Each of the protonated nitrogen atoms forms a very strong hydrogen bond to one of the chloride anions. The hydroxyl group forms a strong hydrogen bond to one of the chloride anions in both conformations, and there are subtle differences in the hydrogen bonding patterns between the conformations. The powder pattern is included in the Powder Diffraction File™ as entry 00-066-1603.

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