scholarly journals Tribarium dicitrate pentahydrate, [Ba3(C6H5O7)2(H2O)4]·H2O

2021 ◽  
Vol 77 (3) ◽  
pp. 251-254
Author(s):  
James A. Kaduk
Keyword(s):  
Hydrogen Bonds ◽  
Density Functional ◽  
Three Dimensional ◽  
Hydroxyl Groups ◽  
Hydrogen Atoms ◽  
Coordination Polyhedra ◽  
X Ray ◽  
Carboxylate Oxygen ◽  
Dimensional Network ◽  
Water Hydrogen

The crystal structure of tribarium dicitrate pentahydrate, [Ba3(C6H5O7)2(H2O)4]·H2O, has been solved and refined using synchrotron X-ray powder diffraction data, and optimized using density functional techniques. The BaO9 and BaO10 coordination polyhedra share edges and corners to form a three-dimensional network. All of the active hydrogen atoms act as donors in O—H...O hydrogen bonds. Most of the acceptors are carboxylate oxygen atoms, but there are also water...water hydrogen bonds. Both of the citrate hydroxyl groups form intramolecular O—H...O hydrogen bonds to terminal carboxyl groups.

Crystal structures of tricalcium citrates

2018 ◽  
Vol 33 (2) ◽  
pp. 98-107 ◽  
Author(s):  
James A. Kaduk
Keyword(s):  
Crystal Structures ◽  
Density Functional ◽  
Three Dimensional ◽  
Water Molecules ◽  
Calcium Citrate ◽  
Powder Diffraction Data ◽  
Coordination Polyhedra ◽  
X Ray ◽  
Calcium Supplements ◽  
Dimensional Network

The crystal structures of calcium citrate hexahydrate, calcium citrate tetrahydrate, and anhydrous calcium citrate have been solved using laboratory and synchrotron X-ray powder diffraction data, and optimized using density functional techniques. Both the hexahydrate and tetrahydrate structures are characterized by layers of edge-sharing Ca coordination polyhedra, including triply chelated Ca. An additional isolated Ca is coordinated by water molecules, and two uncoordinated water molecules occur in the hexahydrate structure. The previously reported polymorph of the tetrahydrate contains the same layers, but only two H2O coordinated to the isolated Ca and two uncoordinated water molecules. Anhydrous calcium citrate has a three-dimensional network structure of Ca coordination polyhedra. The new polymorph of calcium citrate tetrahydrate is the major crystalline phase in several commercial calcium supplements.

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.

scholarly journals Structures of dipotassium rubidium citrate monohydrate, K2RbC6H5O7(H2O), and potassium dirubidium citrate monohydrate, KRb2C6H5O7(H2O), from laboratory X-ray powder diffraction data and DFT calculations

2020 ◽  
Vol 76 (10) ◽  
pp. 1566-1571
Author(s):  
Andrew J. Cigler ◽  
James A. Kaduk
Keyword(s):  
Powder Diffraction ◽  
Diffraction Data ◽  
Metal Ion ◽  
Density Functional ◽  
Three Dimensional ◽  
Hydroxyl Group ◽  
Powder Diffraction Data ◽  
Coordination Polyhedra ◽  
X Ray ◽  
Carboxylate Oxygen

The crystal structures of the isostructural compounds dipotassium rubidium citrate monohydrate, K2RbC6H5O7(H2O), and potassium dirubidium citrate monohydrate, KRb2C6H5O7(H2O), have been solved and refined using laboratory X-ray powder diffraction data, and optimized using density functional techniques. The compounds are isostructural to K3C6H5O7(H2O) and Rb3C6H5O7(H2O), but exhibit different degrees of ordering of the K and Rb cations over the three metal-ion sites. The K and Rb site occupancies correlate well to both the bond-valence sums and the DFT energies of ordered cation systems. The MO6 and MO7 coordination polyhedra share edges to form a three-dimensional framework. The water molecule acts as a donor in two strong charge-assisted O—H...O hydrogen bonds to carboxylate groups. The hydroxyl group of the citrate anion forms an intramolecular hydrogen bond to one of the central carboxylate oxygen atoms.

scholarly journals Tricaesium citrate monohydrate, Cs3C6H5O7·H2O: crystal structure and DFT comparison

2017 ◽  
Vol 73 (4) ◽  
pp. 520-523 ◽  
Author(s):  
Alagappa Rammohan ◽  
Amy A. Sarjeant ◽  
James A. Kaduk
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Water Molecule ◽  
Density Functional ◽  
Three Dimensional ◽  
Carboxylate Group ◽  
Single Crystal Diffraction ◽  
Coordination Polyhedra ◽  
X Ray

The crystal structure of tricaesium citrate monohydrate, 3Cs+·C6H5O73−·H2O, has been solved and refined using laboratory X-ray single-crystal diffraction data, and optimized using density functional techniques. This compound is isostructural to the K+and Rb+compounds with the same formula. The three independent Cs cations are eight-, eight-, and seven-coordinate, with bond-valence sums of 0.91, 1.22, and 1.12 valence units. The coordination polyhedra link into a three-dimensional framework. The hydroxy group forms the usualS(5) hydrogen bond with the central carboxylate group, and the water molecule acts as a donor in two strong hydrogen bonds.

Crystal structure of (Z)-cefprozil monohydrate, C18H19N3O5S(H2O)

2019 ◽  
Vol 34 (4) ◽  
pp. 379-388
Author(s):  
Zachary R. Butler ◽  
James A. Kaduk ◽  
Amy M. Gindhart ◽  
Thomas N. Blanton
Keyword(s):  
Crystal Structure ◽  
Powder Diffraction ◽  
Density Functional ◽  
Three Dimensional ◽  
Ion Pair ◽  
Powder Diffraction Data ◽  
Powder Diffraction File ◽  
X Ray ◽  
Dimensional Network ◽  
Acid Proton

The crystal structure of cefprozil monohydrate has been solved and refined using synchrotron X-ray powder diffraction data and optimized using density functional techniques. Cefprozil monohydrate crystallizes in space group P21 (#4) with a = 11.26513(6), b = 11.34004(5), c = 14.72649(11) Å, β = 90.1250(4)°, V = 1881.262(15) Å3, and Z = 4. Although a reasonable fit was obtained using an orthorhombic model, closer examination showed that many peaks were split and/or had shoulders, and thus the true symmetry was monoclinic. DFT calculations revealed that one carboxylic acid proton moved to an amino group. The structure thus contains one ion pair and one pair of neutral molecules. This protonation was confirmed by infrared spectroscopy. There is an extensive array of hydrogen bonds resulting in a three-dimensional network. The powder pattern has been submitted to ICDD® for inclusion in the Powder Diffraction File™.

The crystal and molecular structure of guanine hydrochloride dehydrate

1965 ◽  
Vol 288 (1414) ◽  
pp. 418-439 ◽  
Keyword(s):  
Hydrogen Bonds ◽  
Least Squares Method ◽  
Three Dimensional ◽  
Water Molecules ◽  
Hydrogen Atoms ◽  
X Ray ◽  
Anisotropic Temperature ◽  
Chlorine Ions ◽  
Atomic Coordinates ◽  
Single Crystal Analysis

The structure of guanine hydrochloride monohydrate has been determined by X-ray single crystal analysis and the parameters (including anisotropic temperature vibrations) have been refined by the three-dimensional least squares method. The unit cell is monoclinic with a = 14.69 ± 0.01, b = 13.40 ± 0.01, c = 4.840 ± 0.005 Å; β = 93.8°± 0.1°; space group P 2 1 / a . For 1600 independent reflexions the final value of the agreement index R was 0.07 and the standard deviations of atomic coordinates are in the region of 0.0035 Å. Two guanine molecules are linked together by hydrogen bonds to form a centrosymmetrical dimer. The dimer is linked by hydrogen bonds to four water molecules which are then hydrogen bonded to two chlorine ions. It is shown that the guanine molecule has associated with it six centres of electron density corresponding to hydrogen atoms and it is therefore in the form (H guanine) + with protonation at the N 7 position.

New Inclusion Compounds of Selenourea with Tetraethyl- and Tetra-n-propylammonium Halides

1997 ◽  
Vol 53 (2) ◽  
pp. 262-271 ◽  
Author(s):  
Q. Li ◽  
T. C. W. Mak
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Three Dimensional ◽  
Crystal Data ◽  
Tetraethylammonium Chloride ◽  
Space Group ◽  
X Ray ◽  
X Ray Crystallography ◽  
Dimensional Network ◽  
Single Column

Air-sensitive selenourea inclusion complexes tetraethylammonium chloride–selenourea (1/2), (C2H5)4N+.C1−.2[(NH2)2CSe] (1), tetra-n-propyl-ammonium chloride–selenourea (1/3), (n-C3H7)4N+.C1−.3[(NH2)2CSe] (2), tetra-n-propylammonium bromide–selenourea (1/3), (n-C3H7)4N+.Br−.3[(NH2)2CSe] (3), and tetra-n-propylammonium iodide–selenourea (1/1), (n-C3H7)4N+.I−.(NH2)2CSe (4), have been prepared and characterized by X-ray crystallography. Crystal data, Mo Kα radiation: (1), space group P21/n, Z = 4, a = 8.768 (5), b = 11.036 (6), c = 19.79 (1) Å, β = 96.92 (1)°, R F = 0.055 for 1468 observed data; (2), space group Cc, Z = 4, a = 18.091 (4), b = 13.719 (3), c = 11.539 (2) Å, β = 111.93 (3)°, R F = 0.051 for 1187 observed data; (3), space group Cc, Z = 4, a = 18.309  (4), b = 13.807 (3), c = 11.577 (2) Å, β = 112.45 (3)°, R F = 0.049 for 1592 observed data; (4), space group P21/n, Z = 4, a = 8.976 (1), b = 14.455 (2), c = 15.377 (3) Å, β = 94.16(1)°, R F = 0.062 for 1984 observed data. In the crystal structure of (1) the parallel alternate arrangement of selenourea–chloride ribbons and selenourea chains generates a puckered layer and the cations are sandwiched between them. In the isomorphous complexes (2) and (3) wide selenourea–halide double ribbons are crosslinked by bridging selenourea molecules via N—H...Se and N—H...X hydrogen bonds [average N...Se = 3.521 (8) and 3.527 (7), N...Cl = 3.354 (8) and N...Br = 3.500 (7) Å in (2) and (3), respectively] to form a channel-like three-dimensional network and the cations are accommodated in a single column within each channel. In the crystal structure of (4) the selenourea molecules are joined in the shoulder-to-shoulder fashion via N—H...Se hydrogen bonds [N...Se = 3.529 (7) and 3.534 (7) Å] to generate a ribbon and each selenourea molecule also forms a pair of chelating N—H...I hydrogen bonds [N...I = 3.567 (7) and 3.652 (7) Å] to an adjacent iodide ion.

scholarly journals Crystal structure of anhydrous tripotassium citrate from laboratory X-ray powder diffraction data and DFT comparison

2016 ◽  
Vol 72 (8) ◽  
pp. 1159-1162 ◽  
Author(s):  
Alagappa Rammohan ◽  
James A. Kaduk
Keyword(s):  
Crystal Structure ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Density Functional ◽  
Three Dimensional ◽  
Carboxylate Group ◽  
Powder Diffraction Data ◽  
Coordination Polyhedra ◽  
X Ray ◽  
Graph Set

The crystal structure of anhydrous tripotassium citrate, [K3(C6H5O7)]n, has been solved and refined using laboratory X-ray powder diffraction data, and optimized using density functional techniques. The three unique potassium cations are 6-, 8-, and 6-coordinate (all irregular). The [KOn] coordination polyhedra share edges and corners to form a three-dimensional framework, with channels running parallel to thecaxis. The only hydrogen bond is an intramolecular one involving the hydroxy group and the central carboxylate group, with graph-set motifS(5).

scholarly journals Crystal structure of trirubidium citrate from laboratory X-ray powder diffraction data and DFT comparison

2017 ◽  
Vol 73 (2) ◽  
pp. 250-253 ◽  
Author(s):  
Alagappa Rammohan ◽  
James A. Kaduk
Keyword(s):  
Crystal Structure ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Density Functional ◽  
Three Dimensional ◽  
Powder Diffraction Data ◽  
Coordination Polyhedra ◽  
X Ray ◽  
Methylene Groups ◽  
Graph Set

The crystal structure of trirubidium citrate, 3Rb+·C6H5O73−, has been solved and refined using laboratory X-ray powder diffraction data, and optimized using density functional techniques. The two independent Rb+cations are seven- and eight-coordinate, with bond-valence sums of 0.99 and 0.92 valence units. The coordination polyhedra share edges and corners to form a three-dimensional framework. The only hydrogen bond is an intramolecular one between the hydroxy group and the central carboxylate, with graph setS(5). The hydrophobic methylene groups lie in pockets in the framework.

scholarly journals cis-Bromidobis(1,2-diaminoethane-κ2 N,N′)(ethylamine-κN)cobalt(III) dibromide

IUCrData ◽  
2018 ◽  
Vol 3 (6) ◽  
Author(s):  
S. Manimaran ◽  
M. Manjunathan ◽  
E. Govindan ◽  
K. Sambathkumar ◽  
K. Anbalagan
Keyword(s):  
Hydrogen Bonds ◽  
Complex Cation ◽  
Three Dimensional ◽  
Title Complex ◽  
Coordination Environment ◽  
X Ray ◽  
Distorted Octahedral Coordination ◽  
Dimensional Network ◽  
Distorted Octahedral ◽  
Distorted Octahedral Coordination Environment

In the title complex, [CoBr(C2H7N)(C2H8N2)2]Br2, the CoIII centre has a distorted octahedral coordination environment, and is surrounded by four N atoms in the equatorial plane, with an additional N atom and the Br atom occupying the axial positions. The complex is isostructural with the Cl compound for which the X-ray structure has also been reported [Anbalagan, Mahalakshmi & Ganeshraja (2011). J. Mol. Struct. 1005, 45–52]. In the crystal, the complex cation and the two counter-anions are linked via N—H...Br hydrogen bonds, forming a three-dimensional network.

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