scholarly journals Structure determination of a novel metal-organic compound synthesized from aluminum and 2,5-pyridinedicarboxylic acid

2011 ◽  
Vol 26 (S1) ◽  
pp. S44-S46 ◽  
Author(s):  
Kenny Ståhl ◽  
Bastian Brink ◽  
Jonas Andersen
Keyword(s):  
The Other ◽  
Dinuclear Complexes ◽  
X Ray Diffraction ◽  
X Ray ◽  
Triclinic System ◽  
Aluminum Ions ◽  
Pyridinedicarboxylic Acid ◽  
Distorted Octahedra ◽  
Metal Organic

The structure of [Al2(pydc)2(μ2-OH)2(H2O)2]n(pydc = 2,5-pyridinedicarboxylate) was successfully determined from powder X-ray diffraction data. The compound crystallizes in the triclinic system (space group P -1) with a = 6.7813(1) Å, b = 7.4944(1) Å, c = 8.5013(1) Å, α = 95.256(1)°, β = 102.478(1)°, γ = 108.979(1)°. The structure consists of aluminum ions coordinating N and O in distorted octahedra, sharing an edge through two hydroxide ions. These dinuclear complexes are connected by pydc ions, which at one end coordinate by nitrogen and oxygen and only by oxygen at the other end. The pydc orientation is reversed in the neighboring pydc, forming double stranded chains interconnected by the aluminum dinuclear complexes in a ladder-like arrangement along [001].

scholarly journals Twinning in Zr-Based Metal-Organic Framework Crystals

Chemistry ◽  
2020 ◽  
Vol 2 (3) ◽  
pp. 777-786
Author(s):  
Sigurd Øien-Ødegaard ◽  
Karl Lillerud
Keyword(s):  
Crystal Structures ◽  
Metal Organic Framework ◽  
Special Importance ◽  
X Ray Diffraction ◽  
X Ray ◽  
Metal Organic ◽  
Ab Initio Structure ◽  
Crystal Twinning ◽  
Organic Framework

Ab initio structure determination of new metal-organic framework (MOF) compounds is generally done by single crystal X-ray diffraction, but this technique can yield incorrect crystal structures if crystal twinning is overlooked. Herein, the crystal structures of three Zirconium-based MOFs, that are especially prone to twinning, have been determined from twinned crystals. These twin laws (and others) could potentially occur in many MOFs or related network structures, and the methods and tools described herein to detect and treat twinning could be useful to resolve the structures of affected crystals. Our results highlight the prevalence (and sometimes inevitability) of twinning in certain Zr-MOFs. Of special importance are the works of Howard Flack which, in addition to fundamental advances in crystallography, provide accessible tools for inexperienced crystallographers to take twinning into account in structure elucidation.

Calibration of a heating/cooling chamber for X-ray diffraction measurements of mechanical stress and crystallographic texture

2006 ◽  
Vol 39 (2) ◽  
pp. 194-201 ◽  
Author(s):  
M. Wohlschlögel ◽  
U. Welzel ◽  
G. Maier ◽  
E. J. Mittemeijer
Keyword(s):  
Thermal Expansion ◽  
The Other ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
X Ray ◽  
Specimen Holder ◽  
Lattice Strains ◽  
Cooling Chamber ◽  
Line Positions

Methods have been developed for the calibration of specimen temperature and of specimen displacement caused by the thermal expansion of the specimen holder in a heating/cooling chamber equipped with a strip or plate heater mounted on an X-ray diffractometer. For the temperature calibration two methods were proposed. One method relies on X-ray diffraction measurements of thermal lattice strains, whereas the other method is based on resistance thermometry. The method proposed for the determination of the temperature-dependent specimen displacement is based on the measurement of diffraction-line positions of the specimen employing two diffraction geometries, one being sensitive to the specimen displacement and the other being insensitive to the specimen displacement. The thermal displacement of the specimen due to thermal expansion of the specimen holder is significant and was determined as about 38 µm per 100 K.

scholarly journals Pirquitasite, Ag2ZnSnS4

2013 ◽  
Vol 69 (2) ◽  
pp. i8-i9 ◽  
Author(s):  
Benjamin N. Schumer ◽  
Robert T. Downs ◽  
Kenneth J. Domanik ◽  
Marcelo B Andrade ◽  
Marcus J. Origlieri
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
General Formula ◽  
Diffraction Data ◽  
The Other ◽  
Tetragonal Symmetry ◽  
X Ray Diffraction ◽  
X Ray ◽  
Anisotropic Displacement Parameters

Pirquitasite, ideally Ag2ZnSnS4(disilver zinc tin tetrasulfide), exhibits tetragonal symmetry and is a member of the stannite group that has the general formulaA2BCX4, withA= Ag, Cu;B= Zn, Cd, Fe, Cu, Hg;C= Sn, Ge, Sb, As; andX= S, Se. In this study, single-crystal X-ray diffraction data are used to determine the structure of pirquitasite from a twinned crystal from the type locality, the Pirquitas deposit, Jujuy Province, Argentina, with anisotropic displacement parameters for all atoms, and a measured composition of (Ag1.87Cu0.13)(Zn0.61Fe0.36Cd0.03)SnS4. One Ag atom is located on Wyckoff site Wyckoff 2a(symmetry -4..), the other Ag atom is statistically disordered with minor amounts of Cu and is located on 2c(-4..), the (Zn, Fe, Cd) site on 2d(-4..), Sn on 2b(-4..), and S on general site 8g. This is the first determination of the crystal structure of pirquitasite, and our data indicate that the space group of pirquitasite isI-4, rather thanI-42mas previously suggested. The structure was refined under consideration of twinning by inversion [twin ratio of the components 0.91 (6):0.09 (6)].

Structural Study of the Compound [(C10O8H2)2 (C4N2H6)].2H2O Synthesized by Hydrothermal Condition

2013 ◽  
Vol 12 (7) ◽  
pp. 377-386
Author(s):  
Manel Halouani ◽  
M. Abdelhedi ◽  
M. Dammak ◽  
N. Audebrand ◽  
L. Ktari
Keyword(s):  
Aqueous Solution ◽  
Hydrothermal Condition ◽  
Carboxyl Group ◽  
X Ray Diffraction ◽  
Compound I ◽  
Unit Cell Parameters ◽  
X Ray ◽  
Cell Parameters ◽  
Triclinic System ◽  
Metal Organic

A new metal–organic compound [(C10O8H2)2(C4N2H6)].2H2O(I) was hydrothermally synthesized from an aqueous solution of Fe (NO3)3 9H2O, (btec) (btec= 1, 2, 4, 5-benzenetetracarboxylic acid) and piperazine. Compound I crystallizes in the triclinic system with the P1 space group. The unit cell parameters are a = 8.271 Å, b = 8.500 Å, c = 9.660 Å, α = 87.12°, β = 89.53°, γ = 70.91°, Z= 2, V= 640.96(6) Å3 and Dx= 1.602g/cm3. The refinement converged into R= 0.047 and RW = 0.059. The structure, determined by single crystal X-ray diffraction, consists of two carboxyl group, piperazine and two molecules of water.

Pitfalls in metal–organic framework crystallography: towards more accurate crystal structures

2017 ◽  
Vol 46 (16) ◽  
pp. 4867-4876 ◽  
Author(s):  
S. Øien-Ødegaard ◽  
G. C. Shearer ◽  
D. S. Wragg ◽  
K. P. Lillerud
Keyword(s):  
Single Crystal ◽  
Structure Determination ◽  
Metal Organic Framework ◽  
Metal Organic Frameworks ◽  
Porous Metal ◽  
X Ray Diffraction ◽  
X Ray ◽  
Metal Organic ◽  
Crystal Twinning

Proper handling of pore-occupying species and crystal twinning in structure determination of porous metal–organic frameworks by single crystal X-ray diffraction.

scholarly journals Determination of the dehydration pathway in a flexible metal–organic framework by dynamic in situ x-ray diffraction

2020 ◽  
Vol 7 (3) ◽  
pp. 034305
Author(s):  
Ian M. Walton ◽  
Jordan M. Cox ◽  
Shea D. Myers ◽  
Cassidy A. Benson ◽  
Travis B. Mitchell ◽  
...  
Keyword(s):  
Metal Organic Framework ◽  
X Ray Diffraction ◽  
X Ray ◽  
Metal Organic ◽  
Flexible Metal ◽  
Organic Framework

scholarly journals Synthesis, structure and hydrogen sorption properties of a pyrazine-bridged copper(I) nitrate metal-organic framework

2019 ◽  
Vol 10 (3) ◽  
pp. 195-200
Author(s):  
Emmanuel Ngwang Nfor ◽  
Andrew David Burrows ◽  
Bridget Ndoye Ndosiri ◽  
Luke Lawrence Keenan ◽  
Offiong Efanga Offiong
Keyword(s):  
Thermal Analysis ◽  
Coordination Polymer ◽  
Metal Organic Framework ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
X Ray ◽  
Triclinic System ◽  
Dimensional Network ◽  
Metal Organic ◽  
Ft Ir

A new copper(I) pyrazine-bridged coordination polymer [Cu2(pyz)3(NO3)2]·2DMF] (pyz = pyrazine) (1) has been synthesized and characterized by FT-IR, TG/DTG, DSC and single crystal X-ray diffraction techniques. The X-ray crystallographic result reveals a two-dimensional network structure containing hexagonal pores. Thermal analysis of compound 1 reveals it is stable to 380 °C, and gas sorption studies showed that it adsorbs 1.04 wt% hydrogen at 1 atm and 77 K. Compound 1 crystallizes in a triclinic system, space group P-1 (no. 2), a = 7.9550(2) Å, b = 7.9810(2) Å, c = 11.0660(3) Å, α = 76.328(1)°, β = 71.115(1)°, γ = 84.577(1)°, V = 645.79(3) Å3, Z = 2, T = 150(2) K, μ(MoKα) = 1.709 mm-1, Dcalc = 1.639 g/cm3, 11111 reflections measured (7° ≤ 2Θ ≤ 54.96°), 2951 unique (Rint = 0.0539) which were used in all calculations. The final R1 was 0.0346 (>2σ(I)) and wR2 was 0.0727 (all data).

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