Neutron‐Diffraction Study of the Structure of Potassium Oxalate Monohydrate: Lone‐Pair Coordination of the Hydrogen‐Bonded Water Molecule in Crystals

AbstractThe crystal structure of mercury(II)chromate hemihydrate, HgCrOThe mercury atom is bonded only to two oxygen atoms, each belonging to a separate Chromate tetrahedron, at the distances 2.055(2) and 2.064(2) Å, the angle O–Hg–O being 179.95(5)°. As each Chromate group is bonded to two mercury atoms, fundamental building elements of the structure are endless chains of the composition (HgCrOIn the water molecule the distances O(W)–H (2 × ) and H–H are 0.945(4) and 1.487(6) Å respectively. The angle H–O(W)–H is 103.7(4)°. In the hydrogen bonds the distance O(W)–H…O between water and Chromate oxygen atoms is 2.961(2) Å with a distance H…O of 2.133(4) Å and an angle O(W)–H…O of 145.6(3)°.

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A neutron diffraction study of the crystal of benzoic acid from 6 to 293 K and a macroscopic-scale quantum theory of the lattice of hydrogen-bonded dimers

Chemical Physics ◽

10.1016/j.chemphys.2016.09.016 ◽

2016 ◽

Vol 479 ◽

pp. 26-35 ◽

Cited By ~ 3

Author(s):

François Fillaux ◽

Alain Cousson

Keyword(s):

Quantum Theory ◽

Neutron Diffraction ◽

Benzoic Acid ◽

Diffraction Study ◽

Neutron Diffraction Study ◽

Macroscopic Scale ◽

Hydrogen Bonded

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A neutron diffraction study on the structure of Cl-solutions in hydrogen-bonded molecular solvents

Journal of Physics Condensed Matter ◽

10.1088/0953-8984/6/21/009 ◽

1994 ◽

Vol 6 (21) ◽

pp. 3839-3848 ◽

Cited By ~ 4

Author(s):

S Erol Okan ◽

P S Salmon

Keyword(s):

Neutron Diffraction ◽

Diffraction Study ◽

Neutron Diffraction Study ◽

Molecular Solvents ◽

Hydrogen Bonded

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Neutron diffraction study of the atomic and molecular motion in hexamethylenetetramine

Acta Crystallographica Section A ◽

10.1107/s0567739470000645 ◽

1970 ◽

Vol 26 (2) ◽

pp. 263-271 ◽

Cited By ~ 29

Author(s):

J. A. K. Duckworth ◽

B. T. M. Willis ◽

G. S. Pawley

Keyword(s):

Neutron Diffraction ◽

Rigid Body ◽

Diffraction Study ◽

Probability Density ◽

Molecular Motion ◽

Lone Pair ◽

Neutron Diffraction Study ◽

Probability Density Functions ◽

Thermal Motion ◽

Density Functions

An accurate neutron diffraction study has been carried out on a single-crystal of hexamethylenetetramine and the measured Bragg intensities have been analysed for the effects of thermal motion. Four different models of the thermal motion have been used in a least-squares refinement of the data: (1) conventional model with ellipsoidal atomic probability density functions; (2) cumulant expansion model with the thermal motion of each atom represented by both second and third cumulant coefficients; (3) as model (1) but including the restriction imposed on the temperature factors by assuming rigid-body molecular motion; (4) as model (2) but including the rigid-body restriction. The best fit is given by model (2), which takes into account deviations from the ellipsoidal atomic probability density functions brought about by libration. Of the rigid-body models, refinement is better for (4) than for (3). Two parameters only, (u 2) and (ω 2) of paper I (Willis & Pawley, Acta Cryst. (1970), A26, 254) are needed to specify the atomic thermal motions for models (3) and (4), whereas nine parameters are required for model (1) and twenty for model (2). The lone-pair electrons of the nitrogen atom have been detected by combining, in a difference Fourier synthesis, the present data with the X-ray measurements of Becka & Cruickshank (Proc. Roy. Soc. A (1963), 273, 435).

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