scholarly journals The crystal structure and spectroscopic properties of catena- (2-methylimidazolium bis(μ2-chloro)-aqua-chloromanganese(II))

2011 ◽  
Vol 76 (2) ◽  
pp. 235-247 ◽  
Author(s):  
Barbara Hachuła ◽  
Monika Pędras ◽  
Maria Nowak ◽  
Joachim Kusz ◽  
Danuta Pentak ◽  
...  

? novel manganese(II) coordination polymer, catena-(2- methylimidazolium bis(?2-chloro)-aqua-chloromanganese(II)), {(C4H7N2)[MnCl3(H2O)]}n, was synthesized, structurally characterized by FTIR spectroscopy and confirmed by single crystal X-ray diffraction analysis. Thermogravimetric analysis and EPR spectroscopy of the compound were also performed. The colourless crystals of the complex were monoclinic, space group P21/c, with the cell parameters a = 11.298(2) ?, b = 7.2485(14) ?, c = 14.709(5) ?, ? = 128.861(18)?, V = 938.0(5) ?3, Z = 4 and R1 = 0.03. The title compound consisted of onedimensional infinite anionic chains [MnCl3(H2O)]n and isolated 2- methylimidazolium cations. The Mn(II) atom was octahedrally coordinated to four bridging chloride anions [Mn-Cl = 2.5109(6) - 2.5688(7) ?], one terminal chloride anion [Mn-Cl = 2.5068(11) ?] and a H2O molecule [Mn-O = 2.2351(17) ?]. A three-dimensional layer structure was constructed via hydrogen bonds and by weak ?-? stacking interactions. A four-step thermal decomposition occurred in the temperature range 25-900?C under nitrogen.

Crystals ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 424 ◽  
Author(s):  
Jia-Le Li ◽  
Wei-Dong Li ◽  
Zi-Wei He ◽  
Shuai-Shuai Han ◽  
Shui-Sheng Chen

A new compound, namely, [Zn(L)2]n (1) was obtained by the reaction of 2-methyl-4-(4H-1,2,4-triazol-4-yl) benzoic acid (HL) with ZnSO4·7H2O, and the compound was characterized by single-crystal X-ray diffraction, infrared spectroscopy, elemental analysis, powder X-ray diffraction (PXRD), and thermogravimetric analysis. The linear HL ligands were deprotonated to be L− anions and act as two-connectors to link Zn2+ to form a two-dimensional (2D) lay structure with (4, 4) topology. The large vacancy of 2D framework allows another layer structure to interpenetrate, resulting in the formation of 2D + 2D → 2D parallel interpenetration in 1. The weak interactions, such as hydrogen bonding and π–π stacking interactions, connect the adjacent 2D layers into a three-dimensional (3D) coordination polymer. The solid-state UV-visible spectroscopy and luminescent property have also been studied.


Author(s):  
Bei Zhang ◽  
Gangxing Guo ◽  
Fang Lu ◽  
Ying Song ◽  
Yong Liu ◽  
...  

Low temperature is a major limiting factor for plant growth and development. Dehydrin proteins are generally induced in response to low-temperature stress. In previous research, a full-length dehydrin gene,PicW2, was isolated fromPicea wilsoniiand its expression was associated with hardiness to cold. In order to gain insight into the mechanism of low-temperature tolerance by studying its three-dimensional crystal structure, prokaryotically expressed PicW2 dehydrin protein was purified using chitosan-affinity chromatography and gel filtration, and crystallized using the vapour-diffusion method. The crystal grew in a condition consisting of 0.1 MHEPES pH 8.0, 25%(w/v) PEG 3350 using 4 mg ml−1protein solution at 289 K. X-ray diffraction data were collected from a crystal at 100 K to 2.82 Å resolution. The crystal belonged to space groupC121, with unit-cell parametersa= 121.55,b= 33.26,c= 73.39 Å, α = γ = 90.00, β = 109.01°. The asymmetric unit contained one molecule of the protein, with a corresponding Matthews coefficient of 2.87 Å3 Da−1and a solvent content of 57.20%. Owing to a lack of structures of homologous dehydrin proteins, molecular-replacement trials failed. Data collection for selenium derivatization of PicW2 and crystal structure determination is currently in progress.


2021 ◽  
Vol 67 (1 Jan-Feb) ◽  
pp. 18
Author(s):  
G. E. Delgado ◽  
P. Grima-Gallardo ◽  
J. A. Aitken ◽  
A. Cárdenas ◽  
I. Brito

The Cu2FeIn2Se5 alloy, belonging to the system (CuInSe2)1-x(FeSe)x with x= ⅓, was synthesized by the melt and annealing technique. The differential thermal analysis (DTA) indicates that this compound melts at 1017 K. The crystal structure of this new quaternary compound was established using powder X-ray diffraction. Cation distribution analysis indicates that this material crystallizes in a P-chalcopyrite structure, space group P2c (Nº 112), with unit cell parameters a = 6.1852(2) Å, c = 12.3633(9) Å, V = 472.98(4) Å3. Cu2FeIn2Se5 is a new adamantane type compound derivative of the sphalerite structure, and consists of a three-dimensional arrangement of distorted CuSe4, FeSe4, and InSe4 tetrahedral connected by common faces.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Akhmatkhodja N. Yunuskhodjayev ◽  
Shokhista F. Iskandarova ◽  
Vahobjon Kh. Sabirov

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.


2005 ◽  
Vol 20 (3) ◽  
pp. 207-211 ◽  
Author(s):  
S. N. Achary ◽  
A. K. Tyagi ◽  
S. K. Kulshreshtha ◽  
O. D. Jayakumar ◽  
P. S. R. Krishna ◽  
...  

The low-cristobalite-type modification of Al0.5Ga0.5PO4 is prepared by annealing the amorphous precipitate of stoichiometric phosphate at 1300 °C. The phase purity of the sample is ascertained by powder X-ray diffraction. The crystal structure is refined by Rietveld refinements of the neutron and X-ray diffraction data of the polycrystalline powder. This compound crystallizes in an orthorhombic lattice with unit cell parameters, a=7.0295(8), b=7.0132(8), and c=6.9187(4) Å, V=341.08(6) Å3, Z=4 (Space group C 2221, No. 20). The crystal structure analysis reveals the random distribution of the Al3+ and Ga3+ having tetrahedral coordination with typical M–O (M=Al3+:Ga3+) bond lengths as 1.74 Å. Similarly, the P5+ have tetrahedral coordination with typical P–O bond lengths 1.52–1.54 Å. The Mo4 and PO4 tetraheda are linked by common corners forming a three-dimensional framework lattice. The details of the crystal structure are presented in this paper.


1964 ◽  
Vol 42 (12) ◽  
pp. 2758-2767 ◽  
Author(s):  
I. D. Brown

Crystals of K2TeBr6 are monoclinic, space group [Formula: see text] with a = 7.521, b = 7.574, and c = 10.730 Å; β = 89° 40′. Atomic positions have been found by three dimensional X-ray diffraction analysis (least squares R = 0.12). The crystals possess a K2PtCl6 structure which is distorted to allow a more efficient packing of the comparatively large anions than is possible with the undistorted cubic form. The stereochemistry of the octahedral TeBr6− ion (Te—Br = 2.71 Å) is discussed.


2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Farzin Marandi ◽  
Ingo Pantenburg ◽  
Gerd Meyer

The new three-dimensional coordination polymer {[Bi(NNO)2(NO3)]·1.5H2O}n(1, NNO−= nicotinateN-oxide) was synthesized and characterized by elemental analysis, IR and1H-NMR spectroscopy, as well as single-crystal X-ray diffraction analysis.1crystallizes in the monoclinic space group C2/c. The crystal structure consists of a rectangular-shaped grid constructed with NNO linkers. Cavities of a diameter of 7.9–8.3 Å2are filled with disordered water molecules. The thermal stability of the compound was evaluated by thermogravimetric analysis.


2013 ◽  
Vol 787 ◽  
pp. 205-207
Author(s):  
Hong Yan Zhou

A compound of (1E,2E)-1,2-di (-3-nitrobenzylidene) hydrazine was synthesized under microwave irradiation (500 w), giving high yields of products (93%). Its structure was determined IR, 1H NMR, MS, elemental analysis and X-ray diffraction. The crystal of the compound is Monoclinic, space group P2(1)/n with a = 6.9611(18), b = 7.823(2), c = 12.999(3) Å, α = 90, β = 105.215(4), γ = 90o, V= 683.1(3) Å3, Z=4, Dc=1.450g/cm3,μ=0.110 mm-1, F(000)=308, R=0.0401 and wR = 0.1131 for 1273 observed reflection with I>2σ (I). π-π stacking interactions contribute to the stability of the structure.


2018 ◽  
Vol 74 (8) ◽  
pp. 981-985
Author(s):  
Flávia H. Silva ◽  
Chris H. J. Franco ◽  
Charlane C. Corrêa ◽  
Renata Diniz

Aromatic polycarboxylate linkers provide structural rigidity and strong interactions among the metal centre and the carboxylate O atoms. A new three-dimensional coordination polymer namely, catena-poly[potassium [tetraaqua(μ-5-sulfobenzene-1,3-dicarboxylato)zinc(II)]], {K[Zn(C8H3O7S)(H2O)4]} n or {K[Zn(SIP)(H2O)4]} n , where SIP is 5-sulfobenzene-1,3-dicarboxylate or 5-sulfoisophthalate, was obtained and characterized by elemental analysis and IR vibrational spectroscopy, and the single-crystal structure was determined by X-ray diffraction analysis. The compound crystallizes in the monoclinic space group P21/n with Z = 4. Topological analysis revealed that K—O interactions form a two-dimensional network, which is uninodal 4-connected and can be described with a point symbol (44.62), and this plane network is classified as sql/Shubnikov. The layers are connected by Zn2+ ions coordinated to the SIP linker, forming a three-dimensional network. This net is a trinodal (3,5,6)-connected system with point symbol (3.44.52.62.73.83).(3.44.52.62.7).(3.72).


2018 ◽  
Vol 83 (02) ◽  
pp. 223-231 ◽  
Author(s):  
Viktor M. Okrugin ◽  
Sharapat S. Kudaeva ◽  
Oxana V. Karimova ◽  
Olga V. Yakubovich ◽  
Dmitry I. Belakovskiy ◽  
...  

AbstractThe new mineral novograblenovite, (NH4,K)MgCl3·6H2O, was found on basaltic lava from the 2012–2013 Tolbachik fissure eruption at the Plosky Tolbachik volcano, Kamchatka Peninsula, Russia. It occurs as prismatic, needle-like transparent crystals together with gypsum and halite. Novograblenovite was formed due to the exposure of the host rocks to eruptive gas exhalations enriched in HCl and NH3. Basalt was the source of potassium and magnesium for the mineral formation. Novograblenovite crystallises in the monoclinic space group C2/c, with unit-cell parameters a = 9.2734(3) Å, b = 9.5176(3) Å, c = 13.2439(4) Å, β = 90.187(2)°, V = 1168.91(2) Å3 and Z = 4. The five strongest reflections in the powder X-ray diffraction pattern [dobs, Å (I, %) (h k l)] are: 3.330 (100) (2 2 0), 2.976 (45) ($\bar{1}\; 1\; 4$), 2.353 (29) ($\bar {2}\; 2\; 4$), 3.825 (26) (2 0 2), 1.997 (25) ($\overline {4\; 2} $ 2). The density calculated from the empirical formula and the X-ray data is 1.504 g cm–3. The mineral is biaxial (+) with α = 1.469(2), β = 1.479(2) and γ = 1.496(2) (λ = 589 nm); 2Vmeas. = 80(10)° and 2Vcalc. = 75.7°. The crystal structure (solved and refined using single-crystal X-ray diffraction data, R1 = 0.0423) is based on the perovskite-like network of (NH4,K)Cl6-octahedra sharing chlorine vertices, and comprises [Mg(H2O)6]2+ groups in framework channels. The positions of all independent H atoms were obtained by difference-Fourier techniques and refined isotropically. All oxygen, nitrogen and chlorine atoms are involved in the system of hydrogen bonding, acting as donors or acceptors. The formula resulting from the structure refinement is [(NH4)0.7K0.3]MgCl3·6H2O. The mineral is named after Prokopiy Trifonovich Novograblenov, one of the researchers of Kamchatka Peninsula, a teacher, naturalist, geographer and geologist.


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