Iodo-oxyapatite, the first example from a new class of modulated apatites

1999 ◽  
Vol 55 (2) ◽  
pp. 165-169 ◽  
Author(s):  
Peter Alberius Henning ◽  
Sven Lidin ◽  
Vačlav Petříček
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Unit Cell ◽  
Apatite Structure ◽  
Flux Method ◽  
Space Group ◽  
X Ray ◽  
New Class ◽  
Oxide Ions

Iodo-oxyapatite [pentadecacalcium iodide oxide nonaphosphate, Ca15(PO4)9IO] was synthesized by a flux method and the structure was solved from single-crystal X-ray data. The crystal structure was refined in the space group P63/m [a = 9.567 (1), c = 20.754 (2) Å and Z = 2] to wR on F of 0.0459. Iodo-oxyapatite has a typical hexagonal apatite structure but the unit cell is tripled along the hexad owing to ordering of the iodide and oxide ions along this direction.

Molecular and crystal structure of a copper(II) complex of sildenafil

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Akhmatkhodja N. Yunuskhodjayev ◽  
Shokhista F. Iskandarova ◽  
Vahobjon Kh. Sabirov
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Unit Cell ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
Piperazine Ring ◽  
Space Group ◽  
X Ray ◽  
Cell Parameters

Abstract The crystal structure of a copper(II) complex of protonated sildenafil, CuCl3C22H31N6O4S⋅2H2O was studied by single crystal X-ray diffraction. The compound crystallizes in the monoclinic space group P21/n with the unit cell parameters a = 15.4292(2), b = 9.06735(12), c = 21.1752(2) Å, V = 2945.48(7) Å3, Z = 4. The Cu atom is coordinated by the sildenafil ligand via the N2 atom of the pyrazolopyrimidine ring and by three chloride anions. Sildenafil is protonated at the methylated N6 atom of the piperazine ring and it is cation ligand with a 1+ charge.

THE CRYSTAL STRUCTURE OF Bi2Te2Se

1961 ◽  
Vol 39 (7) ◽  
pp. 1040-1043 ◽  
Author(s):  
J. A. Bland ◽  
S. J. Basinski
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Unit Cell ◽  
Hexagonal Cell ◽  
Space Group ◽  
X Ray ◽  
Contact Distance

The crystal structure of Bi2Te2Se has been determined by X-ray single crystal methods. The unit cell is trigonal, space group [Formula: see text] with hexagonal cell edges a = 4.28 ± 0.02 Å, c = 29.86 ± 0.10 Å, and there are three formula units per unit cell. The structure is of the C33 type and a comparison is made with other C33 structures, Bi2Se3, Bi2Te3, and Bi2Te2S. An important common feature of these compounds is that the atom on the center of symmetry has a relatively large contact distance with each of its six Bi neighbors.

Reactions between Co(II), 1,2-bis(diphenylphosphino)ethane, and NaBH3CN in the presence and absence of CO. The crystal structure of bis(cyanotrihydroborato)tetrakis(N,N-dimethylformamide)cobalt(II)

1988 ◽  
Vol 66 (7) ◽  
pp. 1770-1775 ◽  
Author(s):  
David J. Elliot ◽  
Sanna Haukilahti ◽  
David G. Holah ◽  
Alan N. Hughes ◽  
Stanislaw Maciaszek ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Unit Cell ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
Triclinic Space Group ◽  
Space Group ◽  
X Ray ◽  
Cell Parameters ◽  
R Factor

Reactions between Co(II), Diphos, and NaBH3CN lead to Co(BH3CN)2(Diphos)2, 1, or [Co(BH3CN)(Diphos)2]X, 2 (X = ClO4 or BPh4), and, in certain solvents, 2 reacts to produce [Co(CN)(Diphos)2](ClO4). Compound 1 can be reversibly converted to Co(BH3CN)2(DMF)4, 4, via Co(BH3CN)2(Diphos)(DMF). In addition, 1 reacts with CO to form the Co(I) and Co(III) compounds [Co(Diphos)2](CO)]X and [Co(Diphos)2(CN)2]X (X = BH3CN or BPh4). Single crystal X-ray diffraction studies of 4 show that the compound crystallizes in the triclinic space group [Formula: see text], with unit cell parameters a = 7.572(6), b = 9.695(6), c = 9.395(6) Å, α = 81.06(4), β = 68.46(5), γ = 68.19(5)°, V = 595.5 Å3, Z = 1, and dcalcd = 1.202 g cm−3. The structure converged to a conventional R factor of 0.040 for 2841 observations and showed an octahedral arrangement of four O atoms from DMF molecules and two trans N-bound BH3CN groups around the Co(II) center.

Crystal structure of triclinic rubidium dichromate, Rb2Cr2O7

1970 ◽  
Vol 48 (4) ◽  
pp. 537-543 ◽  
Author(s):  
N. Ch. Panagiotopoulos ◽  
I. D. Brown
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Least Squares ◽  
Unit Cell ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
Dichromate Ions ◽  
Oxygen Atoms

The crystal structure of triclinic rubidium dichromate has been determined by single crystal X-ray diffraction. The crystal belongs to space group [Formula: see text] with a = 13.554, b = 7.640, c = 7.735 Å, α = 93.64°, β = 98.52°, γ = 88.80° and has four Rb2Cr2O7 units in the unit cell. The final weighted agreement index after refinement by least-squares analysis is 0.058. The configuration of the dichromate ions is similar to that found in most other dichromate structures (Cr—O (bridging) = 1.78 Å, Cr—O (terminal) = 1.62 Å). The two non-equivalent Cr—O—Cr angles are 123 and 137°. The rubidium ions are surrounded by either 8 or 9 oxygen atoms at distances ranging from 2.86 to 3.31 Å. The structure of triclinic Rb2Cr2O7 is similar, but not identical, to that of triclinic K2Cr2O7.

scholarly journals Die Kristallstruktur von Calciumhexacyanoferrat(II)- Hexamethylentetramin-Wasser(1/1/6) Ca2 [Fe(CN)6] · C6H12N4 · 6H2O / The Crystal Structure of Calciumhexacyanoferrate(II)- Hexamethylenetetramine-Water(1/1/6) Ca2[Fe(CN)6] · C 6H12N4 · 6H2O

1988 ◽  
Vol 43 (2) ◽  
pp. 135-137 ◽  
Author(s):  
H.-Jürgen Meyer ◽  
Joachim Pickardt
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Structure Determination ◽  
Unit Cell ◽  
Single Crystal Structure ◽  
Crystal Structure Determination ◽  
Water Molecules ◽  
Monoclinic Space Group ◽  
Space Group ◽  
X Ray

Ca2[Fe(CN)6] · C6H12N4 · 6H2O crystallizes in the monoclinic space group B2/b with a = 1130,2(4), b = 1373,5(4), c = 1353,0(4) pm and γ = 97,17°. The X-ray single crystal structure determination converged at R = 0.055 (2057 reflections). Each of the four Fe(CN)6 octahedra (Z = 4) in the unit cell is coordinated by six Ca atoms with mean NCYAN - Ca distances of 253.5(3) pm. The Ca atoms are bridged by hexamethylenetetramine and water molecules

The Crystal Structure of Bis(2,2′:6′,2″-terpyridine)nickel(II) Perchlorate Hydrate

1995 ◽  
Vol 48 (7) ◽  
pp. 1373 ◽  
Author(s):  
AT Baker ◽  
DC Craig ◽  
AD Rae
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Single Crystal ◽  
Least Squares ◽  
Axial Compression ◽  
Unit Cell ◽  
Monoclinic Space Group ◽  
Octahedral Symmetry ◽  
Space Group ◽  
X Ray

The crystal structure of bis (2,2′:6′,2″-terpyridine)nickel(II) bis (perchlorate) hydrate has been determined by single-crystal X-ray diffractometry . The compound is monoclinic, space group P21, with two molecules in a unit cell of dimensions a 8.827(4), b 8.910(2), c 20.148(9) Ǻ, β 98.71(2)°. The structure was refined by least-squares to a residual of 0.065 for 2184 observed reflections. The compound is found to be isomorphic with the iron(II) analogue previously reported: the cation has approximate D2d symmetry, with the main distortion from octahedral symmetry being an axial compression. Both the solid state reflectance and solution spectra have been measured and some significant differences are noted.

Crystal structure and thermal chemical properties of 2-(2,4-dimethylanilino)-3-methyl-6-diethylaminofluorane

2006 ◽  
Vol 60 (3) ◽  
Author(s):  
X. Li ◽  
C. Ding ◽  
B. Tian ◽  
Q. Liu ◽  
S. Zhang ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Chemical Properties ◽  
Diffraction Method ◽  
Unit Cell ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
Triclinic System

AbstractThe crystal structure of 2-(2,4-dimethylanilino)-3-methyl-6-diethylaminofluorane has been determined by single crystal X-ray diffraction method. The crystal belongs to triclinic system, space group P-1 with unit cell constants a = 11.2877(9) Å, b = 11.9539(9) Å, c = 12.2365(9) Å, α = 97.2580(10)°, β = 116.2850(10)°, γ = 106.3710(10)°, V = 1358.48(18) Å 3, Z = 2, D c = 1.234 g/cm3, μ = 0.079 mm−1, F(000) = 536, R and w(R) are 0.0718 and 0.2055, respectively, for 5239 unique reflections with 3745 observed reflections (I > 2σ(I)).

Darstellung und Struktur des KAu4Sn2 / Preparation and Crystal Structure of KAu4Sn2

1978 ◽  
Vol 33 (10) ◽  
pp. 1077-1079 ◽  
Author(s):  
Heinz-Dieter Sinnen ◽  
Hans-Uwe Schuster
Keyword(s):  
Crystal Structure ◽  
Ternary System ◽  
Single Crystal ◽  
Diffraction Data ◽  
Unit Cell ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
Space Group ◽  
X Ray ◽  
Cell Parameters

Abstract In the course of our investigation of the ternary system K-Au-Sn we obtained the new compound KAu4Sn2. Its crystal structure has been determinated from single crystal X-ray diffraction data. It crystallizes in the tetragonal space group 1̅4̅c2 with unit-cell parameters a = 884.7 and c = 817.8 pm and Z = 4. The structure is comparable to that of the Tl2Se.

X-Ray Crystal Structure of [Rh(OH2)6](ClO4)3.3H2O

1989 ◽  
Vol 42 (11) ◽  
pp. 2051 ◽  
Author(s):  
GD Fallon ◽  
L Spiccia
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Unit Cell ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
Octahedral Sites ◽  
Cell Dimensions ◽  
Unit Cell Dimensions

The crystal structure of [Rh(OH2)6](ClO4)3.3H2O has been determined by single-crystal X-ray diffraction and found to be isomorphous with that of M(ClO4)2.6H2O (M= Fe, Zn, Mn, Co, Ni) and LiClO4.3H2O. Crystal: are hexagonal, space group P63mc with unit cell dimensions a 7.817(2) and c 5.208(1) �. The lattice consists of a uniform arrangement of H2O and ClO4- groups with the RhIII centre occupying 1/3 of the octahedral sites formed by the H2O groups. The RhIII is not situated at the centre of the octahedron. However, the two Rh-O distances [2.128(6) and 2.136(6) �] may be considered identical, i.e. within the errors.

Synthesis, characterization, and crystal structure of two zinc linear dicarboxylates

2016 ◽  
Vol 31 (3) ◽  
pp. 229-232
Author(s):  
Berenice Torruco Baca ◽  
Luis Felipe del Castillo ◽  
Paula Vera-Cruz ◽  
Rubén A. Toscano ◽  
Joelis Rodríguez-Hernández ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Rietveld Method ◽  
Unit Cell ◽  
Monoclinic Space Group ◽  
Unit Cell Parameters ◽  
Space Group ◽  
X Ray ◽  
Cell Parameters ◽  
Zinc Adipate

Two different crystalline structures corresponding to a zinc adipate and a zinc succinate were determined combining: X-ray powder and single-crystal diffraction, infrared spectroscopy, thermal analysis, and true densities experiments. The zinc succinate crystal structure was determined by single-crystal X-ray diffraction. This compound crystallizes in the orthorhombic space-group Cccm with unit-cell parameters a = 4.792(1) Å, b = 21.204(6) Å, c = 6.691(2) Å, V = 679.8(3) Å3, and Z = 8. Zinc adipate crystal structure was refined from the laboratory X-ray powder diffraction data by the Rietveld method. It crystallizes in the monoclinic space group P2/c with unit-cell parameters, a = 16.2037(17)Å, b = 4.7810(2)Å, c = 9.2692(6)Å, β = 90.329(3)°, V = 718.07(9) Å3, and Z = 4. The thermal expansion of it was estimated in 5.40 × 10−5 K−1. This contribution is a step on the way to systematize the regularities in the coordination diversity between linear dicarboxylates and transition metal–inorganic buildings units of metal–organic frameworks.

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