Electron density of orthoboric acid determined by X-ray diffraction at 105 K and <i>ab initio</i> calculations

Gajhede, Michael; Larsen, S.; Rettrup, Sten

doi:10.1107/s0108768186097720

Cited by 51 publications

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“…X -ray diffraction data of sibirskite obtained from Rietveld refinement and the fixation of temperature factors (1.0) for all the atoms required to reduce the calculation time. However, it is expected that the boron atoms will be located at the center of the oxygen triangles present in the model of sibirskite to form the BO 3 triangles, which is common for borate minerals such as takedaite [Ca 3 (BO 3 ) 2 ; Schuckmann, 1969;Vegas et al, 1975] and sassolite (H 3 BO 3 ; Gajhede et al, 1986). The R value for the final simulated structure is 0.243.…”

Section: Structural Analysismentioning

confidence: 99%

Crystal structure of sibirskite (CaHBO3) by Monte Carlo simulation and Rietveld refinement

Miura

Kusachi

2008

Journal of Mineralogical and Petrological Sciences

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The crystal structure of sibirskite (CaHBO 3 ) was solved by the Monte Carlo simulation using powder X -ray diffraction data and confirmed by the Rietveld refinement. The mineral sibirskite is monoclinic with space group P2 1 /a and cell constants of a = 8.643(6), b = 9.523(2), c = 3.567(3) Å, and β = 119.23(3)°. The unit cell consists of independent atoms such as calcium, boron, hydrogen, and three oxygen atoms. The calcium atom is surrounded by six oxygen atoms in an octahedral coordination, and a symmetrical pair of edge -shared CaO 6 octahedra forming a double chain elongates the crystallographic c axis. The CaO 6 double chains are not directly connected to each other. The BO 3 triangles are linked to one vertical and two shared oxygen atoms in three CaO 6 double chains to form the sibirskite structure. Sibirskite is isostructural with nahcolite (NaHCO 3 ), which consists of NaO 6 double chains and CO 3 triangles.

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Section: Structural Analysismentioning

confidence: 99%

Crystal structure of sibirskite (CaHBO3) by Monte Carlo simulation and Rietveld refinement

Miura

Kusachi

2008

Journal of Mineralogical and Petrological Sciences

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“…285389 (1), 285390 (2), 285391 (3 AE H 2 O), 285392 (4), 285393 (5), 285394 (6), and 285395 (7). Copies of the data can be obtained free of charge on application to The Director, CCDC, 12 Union Road, Cambridge, CB2 1EZ, UK, fax: +44 1223 366 033, e-mail: deposit@ccdc.ac.uk or on the web www: http://www.ccdc.cam.ac.uk.…”

Section: Supplementary Materialsmentioning

confidence: 99%

“…(c) The enantiomers may be able to substitute each other in the crystal; consequently, the diastereomeric salts may form solid solutions of the type (R-I/S-I)R-II [4]. Structural studies devoted to the first category, i.e., to successful resolution via formation of diastereomers, have associated packing and intermolecular interactions, especially hydrogen bonding, to solubility or efficiency of resolution [5][6][7][8][9][10][11][12].…”

Section: Introductionmentioning

confidence: 99%

Unexpected solids from enantiopure cationic palladium complexes and racemic anions: A structural study of chiral non-discrimination

Kalf

Wang

Englert

2006

Journal of Organometallic Chemistry

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“…This structure has not been verified in subsequent X-ray (Zachariasen, 1954;Gajhede, Larsen & Rettrup, 1986) and neutron (Craven & Sabine, 1966) diffraction analyses. Since the electron diffraction data had been assigned phase values from the earliest X-ray structure, it is of particular interest to determine what results will be found from an ab initio structure analysis in which no a priori assumptions are made about the heavy-atom positions.…”

Section: Introductionmentioning

confidence: 98%

Direct methods in electron crystallography - structure analysis of boric acid

Dorset¹

1992

Acta Cryst Sect A

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Direct phasing methods based on the probabilistic estimate of triplet and quartet structure invariants are used to determine the crystal structure of boric acid from room-temperature electron diffraction data published by Cowley [Acta Cryst. (1953), 6, 522-529] and also new low-temperature data collected at or below 128 K. In either instance, the resulting structure is the monolayer found earlier and the bond distances and angles for heavy atoms computed from the atomic coordinates agree well with three-dimensional X-ray and neutron diffraction determinations. H-atom positions are not accurately defined, however. A reason for the monolayer structure resulting from the analysis of electron diffraction data is suggested, given the continuous reciprocal-lattice rods observed in diffraction patterns from tilted crystals also seen earlier at room temperature.

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Electron density of orthoboric acid determined by X-ray diffraction at 105 K and ab initio calculations

Cited by 51 publications

References 0 publications

Crystal structure of sibirskite (CaHBO3) by Monte Carlo simulation and Rietveld refinement

Crystal structure of sibirskite (CaHBO3) by Monte Carlo simulation and Rietveld refinement

Unexpected solids from enantiopure cationic palladium complexes and racemic anions: A structural study of chiral non-discrimination

Direct methods in electron crystallography - structure analysis of boric acid

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