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.

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™.

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 structures of two magnesium citrates from powder diffraction data

2020 ◽  
Vol 76 (10) ◽  
pp. 1611-1616
Author(s):  
James A. Kaduk
Keyword(s):  
Crystal Structures ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Density Functional ◽  
Powder Diffraction Data ◽  
Magnesium Citrate ◽  
Coordination Polyhedra ◽  
X Ray ◽  
Cation Coordination ◽  
Citrate Anion

The crystal structures of magnesium hydrogen citrate dihydrate, Mg(HC6H5O7)(H2O)2, (I), and bis(dihydrogen citrato)magnesium, Mg(H2C6H5O7)2, (II), have been solved and refined using synchrotron X-ray powder diffraction data, and optimized using density functional techniques. In (I), the citrate anion occurs in the trans, trans-conformation, and triply chelates to the Mg cation. In (II), the citrate anion is trans, gauche, and doubly chelates to the Mg cation. In both compounds the Mg cation coordination polyhedron is an octahedron. In (I), the MgO6 coordination polyhedra are isolated, while in (II), they share edges to form chains. Strong O—H...O hydrogen bonds are prominent in the two structures, as well as in the previously reported magnesium citrate decahydrate.

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.

Crystal structure of strontium hydrogen citrate monohydrate, Sr(HC6H5O7)(H2O)

2021 ◽  
pp. 1-9
Author(s):  
James A. Kaduk
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Density Functional ◽  
Water Molecules ◽  
Powder Diffraction Data ◽  
Unknown Compound ◽  
Coordination Polyhedra ◽  
X Ray ◽  
Carboxylic Acid Groups ◽  
Triclinic Unit Cell

The crystal structure of strontium hydrogen citrate monohydrate has been solved using laboratory X-ray powder diffraction data, refined using both laboratory and synchrotron data, and optimized using density functional techniques. Strontium hydrogen citrate monohydrate crystallizes in space group C2/c (#15) with a = 25.15601(17), b = 10.90724(6), c = 6.37341(4) Å, β = 91.9846(6)°, V = 1747.704(12) Å3, and Z = 8. The Sr coordination and the hydrogen bonding result in a layered structure. The SrO8 coordination polyhedra share edges to form corrugated layers parallel to the bc-plane. Hydrogen bonds between the carboxylic acid groups and water molecules link the layers. Intermolecular hydroxyl–carboxyl hydrogen bonds also link the layers in a ring pattern with a graph set symbol R2,2(12). After storage for 2 years, partial re-crystallization occurred, to an as-yet unknown compound with a triclinic unit cell.

scholarly journals Sodium dipotassium citrate, NaK2C6H5O7

2016 ◽  
Vol 72 (3) ◽  
pp. 403-406 ◽  
Author(s):  
Alagappa Rammohan ◽  
James A. Kaduk
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Density Functional ◽  
Three Dimensional ◽  
Bond Valence ◽  
Carboxylate Group ◽  
Powder Diffraction Data ◽  
X Ray ◽  
Dimensional Network ◽  
Bond Valence Sum

The crystal structure of sodium dipotassium citrate, Na+·2K+·C6H5O73−, has been solved and refined using laboratory X-ray powder diffraction data, and optimized using density functional techniques. The Na+and one of the K+cations are six-coordinate, with bond-valence sums of 1.13 and 0.92 valence units, respectively, while another crystallographically independent K+cation is seven-coordinate with a bond-valence sum of 1.20. The [KO6] and [KO7] polyhedra share edges and corners to form layers perpendicular to thebaxis. The distorted [NaO6] octahedra share edges to form chains along theaaxis. The result is a three-dimensional network. The only O—H...O hydrogen bond is an intramolecular one between the hydroxy group and a terminal carboxylate group.

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 Sodium dirubidium citrate, NaRb2C6H5O7, and sodium dirubidium citrate dihydrate, NaRb2C6H5O7(H2O)2

2019 ◽  
Vol 75 (4) ◽  
pp. 432-437 ◽  
Author(s):  
Andrew J. Cigler ◽  
James A. Kaduk
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Atom ◽  
Powder Diffraction ◽  
Density Functional ◽  
Three Dimensional ◽  
Water Molecules ◽  
Carboxylate Group ◽  
Powder Diffraction Data ◽  
X Ray ◽  
Carboxylate Groups

The crystal structures of sodium dirubidium citrate {poly[μ-citrato-dirubidium(I)sodium(I)], [NaRb2(C6H5O7)] n } and sodium dirubidium citrate dihydrate {poly[diaqua(μ-citrato)dirubidium(I)sodium(I)], [NaRb2(C6H5O7)(H2O)2] n } have been solved and refined using laboratory X-ray powder diffraction data, and optimized using density functional techniques. Both structures contain Na chains and Rb layers, which link to form different three-dimensional frameworks. In each structure, the citrate triply chelates to the Na+ cation. Each citrate also chelates to Rb+ cations. In the dihydrate structure, the water molecules are bonded to the Rb+ cations; the Na+ cation is coordinated only to citrate O atoms. Both structures contain an intramolecular O—H...O hydrogen bond between the hydroxy group and one of the terminal carboxylate groups. In the structure of the dihydrate, each hydrogen atom of the water molecules participates in a hydrogen bond to an ionized carboxylate group.

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.

Two polymorphs of 2-ethyl-3-hydroxy-6-methylpyridinium hydrogenN-acetyl-L-glutamate from powder diffraction data

2013 ◽  
Vol 69 (12) ◽  
pp. 1549-1552 ◽  
Author(s):  
Vladimir V. Chernyshev ◽  
Sergey Y. Efimov ◽  
Ksenia A. Paseshnichenko ◽  
Andrey A. Shiryaev
Keyword(s):  
Hydrogen Bonds ◽  
Crystal Structures ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Crystal Packing ◽  
Three Dimensional ◽  
Powder Diffraction Data ◽  
Screw Axis ◽  
Dimensional Network ◽  
Polymorphic Modifications

The title salt, C8H12NO+·C7H10NO5−, crystallizes in two polymorphic modifications,viz.monoclinic (M) and orthorhombic (O). The crystal structures of both polymorphic modifications have been established from laboratory powder diffraction data. The crystal packing motifs in the two polymorphs are different, but the conformations of the anions are generally similar. InM, the anions are linked by pairs of hydrogen bonds of the N—H...O and O—H...O types into chains along theb-axis direction, and neighbouring molecules within the chain are related by the 21screw axis. The cations link these chainsviaO—H...O and N—H...O hydrogen bonds into layers parallel to (001). InO, the anions are linked by O—H...O hydrogen bonds into helices along [001], and neighbouring molecules within the helix are related by the 21screw axis. The neighbouring helical turns are linked by N—H...O hydrogen bonds. The cations link the helicesviaO—H...O and N—H...O hydrogen bonds, thus forming a three-dimensional network.

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