scholarly journals Crystal structure of dicesium hydrogen citrate from laboratory single-crystal and powder X-ray diffraction data and DFT comparison

2017 ◽  
Vol 73 (2) ◽  
pp. 231-234 ◽  
Author(s):  
Alagappa Rammohan ◽  
Amy A. Sarjeant ◽  
James A. Kaduk
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Single Crystal ◽  
Diffraction Data ◽  
Density Functional ◽  
Three Dimensional ◽  
Mirror Plane ◽  
Coordination Polyhedra ◽  
X Ray ◽  
Methylene Groups

The crystal structure of dicesium hydrogen citrate, 2Cs+·C6H6O72−, has been solved using laboratory X-ray single-crystal diffraction data, refined using laboratory powder X-ray data, and optimized using density functional techniques. The Cs+cation is nine-coordinate, with a bond-valence sum of 0.92 valence units. The CsO9coordination polyhedra share edges and corners to form a three-dimensional framework. The citrate anion is located on a mirror plane. Its central hydroxy/carboxylate O—H...O hydrogen bond is short, and (unusually) intermolecular. The centrosymmetric end-end carboxylate hydrogen bond is exceptionally short (O...O = 2.416 Å) and strong. These hydrogen bonds contribute 16.5 and 21.7 kcal mol−1, respectively, to the crystal energy. The hydrophobic methylene groups occupy pockets in the framework.

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 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 monohydrate from laboratory X-ray powder diffraction data and DFT comparison

2017 ◽  
Vol 73 (2) ◽  
pp. 227-230 ◽  
Author(s):  
Alagappa Rammohan ◽  
James A. Kaduk
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Density Functional ◽  
Three Dimensional ◽  
Powder Diffraction Data ◽  
Hydrogen Bond Donor ◽  
X Ray ◽  
Intramolecular Hydrogen

The crystal structure of the title compound, 3Rb+·C6H5O73−·H2O, has been solved and refined using laboratory X-ray powder diffraction data, and optimized using density functional techniques. The hydroxy group participates in an intramolecular hydrogen bond to the deprotonated central carboxylate group with graph-set motifS(5). The water molecule acts as a hydrogen-bond donor to both terminal and central carboxylate O atoms. The three independent rubidium cations are seven-, six- and six-coordinate, with bond-valence sums of 0.84, 1.02, and 0.95, respectively. In the extended structure, their polyhedra share edges and corners to form a three-dimensional network. The hydrophobic methylene groups occupy channels along thebaxis.

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.

scholarly journals The caesium phosphates Cs3(H1.5PO4)2(H2O)2, Cs3(H1.5PO4)2, Cs4P2O7(H2O)4, and CsPO3

2020 ◽  
Vol 151 (9) ◽  
pp. 1317-1328
Author(s):  
Matthias Weil ◽  
Berthold Stöger
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Single Crystal ◽  
Diffraction Data ◽  
Room Temperature ◽  
Structure Type ◽  
Solid State Reactions ◽  
X Ray Diffraction ◽  
Hydrogen Phosphate ◽  
X Ray

Abstract The caesium phosphates Cs3(H1.5PO4)2(H2O)2 and Cs3(H1.5PO4)2 were obtained from aqueous solutions, and Cs4P2O7(H2O)4 and CsPO3 from solid state reactions, respectively. Cs3(H1.5PO4)2, Cs4P2O7(H2O)4, and CsPO3 were fully structurally characterized for the first time on basis of single-crystal X-ray diffraction data recorded at − 173 °C. Monoclinic Cs3(H1.5PO4)2 (Z = 2, C2/m) represents a new structure type and comprises hydrogen phosphate groups involved in the formation of a strong non-symmetrical hydrogen bond (accompanied by a disordered H atom over a twofold rotation axis) and a very strong symmetric hydrogen bond (with the H atom situated on an inversion centre) with symmetry-related neighbouring anions. Triclinic Cs4P2O7(H2O)4 (Z = 2, P$$\bar{1}$$ 1 ¯ ) crystallizes also in a new structure type and is represented by a diphosphate group with a P–O–P bridging angle of 128.5°. Although H atoms of the water molecules were not modelled, O···O distances point to hydrogen bonds of medium strengths in the crystal structure. CsPO3 is monoclinic (Z = 4, P21/n) and belongs to the family of catena-polyphosphates (MPO3)n with a repetition period of 2. It is isotypic with the room-temperature modification of RbPO3. The crystal structure of Cs3(H1.5PO4)2(H2O)2 was re-evaluated on the basis of single-crystal X-ray diffraction data at − 173 °C, revealing that two adjacent hydrogen phosphate anions are connected by a very strong and non-symmetrical hydrogen bond, in contrast to the previously described symmetrical bonding situation derived from room temperature X-ray diffraction data. In the four title crystal structures, coordination numbers of the caesium cations range from 7 to 12. Graphic abstract

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

2017 ◽  
Vol 73 (1) ◽  
pp. 92-95 ◽  
Author(s):  
Alagappa Rammohan ◽  
James A. Kaduk
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Density Functional ◽  
Acid Group ◽  
Powder Diffraction Data ◽  
X Ray ◽  
Methylene Groups ◽  
A Chain

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.

The crystal structure of galeite, Na15(SO4)5F4Cl

1975 ◽  
Vol 40 (312) ◽  
pp. 357-361 ◽  
Author(s):  
L. Fanfani ◽  
A. Nunzi ◽  
P. F. Zanazzi ◽  
A. R. Zanzari
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Least Squares ◽  
Diffraction Data ◽  
Three Dimensional ◽  
Thermal Parameters ◽  
X Ray Diffraction ◽  
Cell Content ◽  
X Ray ◽  
Structure Factors

SummaryThe crystal structure of galeite from Searles Lake (California) has been determined by means of X-ray diffraction data on a single crystal. A possible structure was derived from that of schairerite on the basis of chemical and lattice analogies and was confirmed by comparison of the observed diffractometric structure factors with the calculated ones. The refinement was performed by least-squares methods employing isotropic thermal parameters and assuming that atoms related by translational pseudosymmetry exhibit equal thermal parameters. The final R value is 0·09. The cell content is 3[Na15(SO4)5F4Cl]; the space group is P31m The lattice dimensions are a 12·197(4)Å, c 13·955(10) Å The marked subcell has P3m1 symmetry and a 7·042Å, c 13·955 Å. The crystal structure of galeite consists of a three-dimensional framework, formed by coordination octahedra around Na+ ions, including tetrahedral holes with sulphur atoms at the centres. The three-dimensional framework can be considered built up by five octahedral sheets (seven sheets can be recognized in schairerite and six in sulphohalite). The very close analogies occurring in the structures of galeite and schairerite are discussed.

scholarly journals Ab initio and DFT study on Cu (II) complex salicylate derivative

2014 ◽  
Vol 70 (a1) ◽  
pp. C1442-C1442
Author(s):  
Karthikeyan Natarajan ◽  
Sathya Duraisamy ◽  
Sivakumar Kandasamy
Keyword(s):  
Crystal Structure ◽  
Density Functional Theory ◽  
Single Crystal ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Density Functional ◽  
Powder Diffraction Data ◽  
X Ray Diffraction ◽  
Functional Theory ◽  
X Ray

X -ray diffraction becomes a routine process these decades for determining crystal structure of the materials. Most of the crystal structures solved nowadays is based on single crystal X-ray diffraction because it solves the crystal and molecular structures from small molecules to macro molecules without much human intervention. However it is difficult to grow single crystals of sufficient size and quality for conventional single-crystal X-ray diffraction studies. In such cases it becomes essential that structural information can be determined from powder diffraction data. With the recent developments in the direct-space approaches for structure solution, ab initio crystal structure analysis of molecular solids can be accomplished from X-ray powder diffraction data. It should be recalled that crystal structure determination from laboratory X-ray powder diffraction data is a far more difficult task than that of its single-crystal counterpart, particularly when the molecule possesses considerable flexibility or there are multiple molecules in the asymmetric unit. Salicylic acid and its derivatives used as an anti-inflammatory drug are known for its numerous medicinal applications. In our study, we synthesized mononuclear copper (II) complex of salicylate derivative. The structural characterization of the prepared compound was carried out using powder X-ray diffraction studies. Crystal structure of the compound has been solved by direct-space approach and refined by a combination of Rietveld method using TOPAS Academic V4.1. Density Functional Theory (DFT) calculations have to be carried in the solid state for the compound using GaussianW9.0 in the frame work of a generalized-gradient approximation (GGA). The geometry optimization was to be performed using B3LYP density functional theory. The atomic coordinates were taken from the final X-ray refinement cycle.

Crystal structure of dicadmium(II) ethylenediphosphinetetraacetate octahydrate

1991 ◽  
Vol 56 (7) ◽  
pp. 1454-1460 ◽  
Author(s):  
Jaroslav Podlaha ◽  
Jana Podlahová
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Single Crystal ◽  
Diffraction Data ◽  
Title Compound ◽  
Water Molecules ◽  
X Ray Diffraction ◽  
Coordination Polyhedra ◽  
X Ray ◽  
Carboxylate Groups

The crystal structure of the title compound containing a phosphorus analogue of EDTA as the ligand was determined from single-crystal X-ray diffraction data and refined to R = 0.028 for 1 920 observed reflections. The crystals are monocyclic, space group P21/c,a = 8.6169(8), b = 16.0539(9), c = 8.2504(6)Å, β = 103.458(7)° and Z = 2. The structure is completely different from that of the nitrogen prototype, [CdEDTA]2-. It consists of double-stranded polymeric layers which are composed of metal coordination polyhedra linked by μ6-hexadentate ligands; the layers lie parallel to the bc plane and are joined along the a axis through hydrogen bonding donated by water molecules. Because of steric requirements of phosphorus, the coordination polyhedron around Cd is greatly distorted and can best be described as a 5 + 3 type. One P atom, two oxygen atoms from two monodentate carboxylate groups and two water molecules form an approximate trigonal bipyramid and further three more remote carboxylate oxygens complete the arrangement, resulting in an O7P distorted bicapped trigonal prism.

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.

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