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

2021 ◽  
pp. 1-9
Author(s):  
James A. Kaduk

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.

Author(s):  
Alagappa Rammohan ◽  
Amy A. Sarjeant ◽  
James A. Kaduk

The crystal structure of disodium hydrogen citrate sesquihydrate, 2Na2+·C6H6O72−·1.5H2O, has been solved and refined using laboratory X-ray single-crystal diffraction data, and optimized using density functional techniques. The asymmetric unit contains two independent hydrogen citrate anions, four sodium cations and three water molecules. The coordination polyhedra of the cations (three with a coordination number of six, one with seven) share edges to form isolated 8-rings. The un-ionized terminal carboxylic acid groups form very strong hydrogen bonds to non-coordinating O atoms, with O...O distances of 2.46 Å.


Author(s):  
Alagappa Rammohan ◽  
James A. Kaduk

The crystal structure of caesium dihydrogen citrate, Cs+·H2C6H5O7−, has been solved and refined using laboratory X-ray powder diffraction data, and optimized using density functional techniques. The coordination polyhedra of the nine-coordinate Cs+cations share edges to form chains along thea-axis. These chains are linked by corners along thec-axis. The un-ionized carboxylic acid groups form two different types of hydrogen bonds; one forms a helical chain along thec-axis, and the other is discrete. The hydroxy group participates in both intra- and intermolecular hydrogen bonds.


2018 ◽  
Vol 33 (2) ◽  
pp. 98-107 ◽  
Author(s):  
James A. Kaduk

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.


2018 ◽  
Vol 33 (4) ◽  
pp. 298-302
Author(s):  
Austin M. Wheatley ◽  
James A. Kaduk ◽  
Amy M. Gindhart ◽  
Thomas N. Blanton

The crystal structure of bretylium tosylate has been solved and refined using synchrotron X-ray powder diffraction data, and optimized using density functional techniques. Bretylium tosylate crystallizes in space group C2/c (#15) with a = 32.6238(4), b = 12.40353(14), c = 9.93864(12) Å, β = 101.4676(10), V = 3941.39(5) Å3, and Z = 8. The sample exhibited visible decomposition in the X-ray beam. The unusual displacement ellipsoid of the Br atom probably indicates that the decomposition in the beam involves the Br atom. The crystal structure can be viewed as layered parallel to the bc plane. The layers are double, the center consisting of the cation/anion polar interactions and the outer surface of the double layers consists of hydrocarbon interactions. In the absence of normal hydrogen bond donors, the only hydrogen bonds in the bretylium tosylate structure are C–H…O hydrogen bonds. The powder pattern has been submitted to ICDD® for inclusion in the Powder Diffraction File™.


2016 ◽  
Vol 72 (8) ◽  
pp. 1159-1162 ◽  
Author(s):  
Alagappa Rammohan ◽  
James A. Kaduk

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).


Author(s):  
Alagappa Rammohan ◽  
James A. Kaduk

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.


Author(s):  
Alagappa Rammohan ◽  
James A. Kaduk

The crystal structure of dirubidium hydrogen citrate, 2Rb+·HC6H5O72−, has been solved and refined using laboratory X-ray powder diffraction data, and optimized using density functional techniques. The un-ionized carboxylic acid group forms helical chains of very strong hydrogen bonds (O...O ∼ 2.42 Å) along thebaxis. The hydroxy group participates in a chain of intra- and intermolecular hydrogen bonds along thecaxis. These hydrogen bonds result in corrugated hydrogen-bonded layers in thebcplane. The Rb+cations are six-coordinate, and share edges and corners to form layers in theabplane. The interlayer contacts are composed of the hydrophobic methylene groups.


2015 ◽  
Vol 30 (4) ◽  
pp. 333-339 ◽  
Author(s):  
James A. Kaduk ◽  
Kai Zhong ◽  
Amy M. Gindhart ◽  
Thomas N. Blanton

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.


2021 ◽  
Vol 36 (1) ◽  
pp. 56-62
Author(s):  
James A. Kaduk ◽  
Amy M. Gindhart ◽  
Thomas N. Blanton

The crystal structure of tezacaftor Form A has been solved and refined using synchrotron X-ray powder diffraction data, and optimized using density functional techniques. Tezacaftor Form A crystallizes in space group C2 (#5) with a = 21.05142(6), b = 6.60851(2), c = 17.76032(5) Å, β = 95.8255(2)°, V = 2458.027(7) Å3, and Z = 4. The crystal structure is dominated by van der Waals interactions. O–H⋯O hydrogen bonds link the molecules in chains along the b-axis, and there are a variety of C–H⋯O hydrogen bonds, both intra- and intermolecular. The powder pattern has been submitted to ICDD® for inclusion in the Powder Diffraction File™ (PDF®).


2021 ◽  
pp. 1-3
Author(s):  
James A. Kaduk ◽  
Amy M. Gindhart ◽  
Thomas N. Blanton

The crystal structure of pazopanib hydrochloride Form 1 has been refined using synchrotron X-ray powder diffraction data and optimized using density functional theory techniques. Pazopanib hydrochloride crystallizes in space group P-1 (#2) with a = 8.45008(6), b = 8.71310(12), c = 16.05489(35) Å, α = 79.5996(9), β = 86.4784(5), γ = 87.3764(3)°, V = 1159.724(9) Å3, and Z = 2. The crystal structure is essentially identical to that of CSD Refcode CEVYEK. There are four strong N–H⋯Cl hydrogen bonds to the chloride anion. Several additional weaker N–H⋯Cl and C–H⋯Cl hydrogen bonds are also present. A variety of C–H⋯O, C–H⋯N, and N–H⋯S hydrogen bonds also contribute to the lattice energy. The powder pattern has been submitted to ICDD® for inclusion in the Powder Diffraction File™.


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