scholarly journals Crystal structures of bis-{N-[1-(pyridin-2-yl-κN)ethylidene]nicotine hydrazide-κ2N’,O}cobalt(II)bis(perchlorate) dihydrate and bis-{N'-[1-(pyridin-2-yl-κN)ethylidene]nicotinohydrazide-κ2N',O}copper(II) perchlorate

2021 ◽  
Vol 12 (2) ◽  
pp. 159-164
Author(s):  
Moussa Faye ◽  
Mouhamadou Moustapha Sow ◽  
Papa Aly Gaye ◽  
Moussa Dieng ◽  
Mohamed Gaye

Complexes of Co(II), [Co(C26H24N8O2)]·(ClO4)2·(H2O)2 (1), and Cu(II), [Cu(C26H23N8O2)]·(ClO4) (2), have been synthesized. The prepared two compounds were characterized by elemental analysis, infrared and their structures were determined by single-crystal X-ray diffraction. The compound 1 crystallizes in the triclinic space group P-1 with the following unit cell parameters: a = 8.880 (5) Å, b = 10.529 (5) Å, c = 18.430 (5) Å, α = 99.407 (5)°, β = 102.174 (5)°, γ = 100.652 (5)°, V = 1618.2 (13) Å3, Z = 2, T = 293(2), μ(MoKα) = 0.77 mm-1, Dcalc = 1.582 g/cm3, 16135 reflections measured (5.050° ≤ 2q ≤ 59.152°), 7648 unique, Rint = 0.034 which were used in all calculations. The final R1 was 0.066 (I ≥ 2σ(I)) and wR2 was 0.22 (all data). The compound 2 crystallizes in the monoclinic space group P21/c with the following unit cell parameters : a = 11.652 (5) Å, b = 16.540 (5) Å, c = 14.512 (5) Å, β = 93.495 (5)°, V = 2791.6 (18) Å3, Z = 4, T = 293(2), μ(MoKα) = 1.05 mm-1, Dcalc = 1.768 g/cm3, 15592 reflections measured (5.624° ≤ 2θ ≤ 58.804°), 6630 unique, Rint = 0.025 which were used in all calculations. The final R1 was 0.050 (I ≥ 2σ(I)) and wR2 was 0.144 (all data). In both complexes, the ligand acts in a tridentate fashion. In the structure of the mononuclear complex 1, the Co(II) cation is coordinated by two ligand molecules. The basal plane around the Co(II) cation is occupied by two pyridine nitrogen atoms and two carbonyl oxygen atoms. Two imino nitrogen atoms occupy the apical positions of the distorted square-pyramidal geometry. The mononuclear 2 consists of a Cu(II) coordinated by one ligand and one monodeprotonated ligand molecule. The metal center lies in a distorted square bipyramidal environment. The basal plane around the Cu(II) is occupied by two pyridine nitrogen atoms and two carbonyl oxygen atoms, the apical position being occupied by the two imino nitrogen atoms.

1996 ◽  
Vol 51 (7) ◽  
pp. 952-958 ◽  
Author(s):  
C. Werner ◽  
E. Kemnitza ◽  
H. Worzalab ◽  
S. Trojanov

From the binary systems M2SO4/H2SO4 (M = Ba. Sr), two new hydrogen sulfates, (Ba(HSO4)2(H2SO4)3 and Sr(HSO4)2(H2SO4), have been synthesized and structurally characterized.Ba(HSO4)2(H2SO4)3 crystallizes in the orthorhombic space group P21212, with unit cell parameters a = 4.680(1), b = 11.267(2), c = 29.188(6)A, Z = 4. BaO9 trigonal prismatic polyhedra with Ba-O distances of 2.68 - 3.02 Å from nine different SO4 tetrahedra are connected via common bases and build “isolated” columns consisting of O-S-O bridged double chains along the x-axis. HSO4 and H2SO4 tetrahedra are linked via hydrogen bonds to form columns. Sr(HSO4)2(HTSO4) crystallizes in the triclinic space group P1̄ with unit cell parameters a = 5.971(1), b = 8.468(2), c = 10.226(2)Å, α = 81.71(3), β = 83.30(3), γ = 70.69(3)°, Z = 2. Sr is coordinated by nine oxygen atoms from seven different SO4 tetrahedra with Sr-O distances of 2.47 - 2.84 Å. The SrO9 polyhedra build layers consisting of O-S-O bridged chains. Three crystallographically different SO4 tetrahedra are linked via hydrogen bonds to form a kind of flattened cylinder along the x-axis.


2007 ◽  
Vol 62 (7) ◽  
pp. 873-880 ◽  
Author(s):  
Hamdi Ben Yahia ◽  
Etienne Gaudin ◽  
Jacques Darriet

Abstract The new compounds A2MnV2O7 (A = K, Rb) with structures related to the melilite-type have been synthesized by a solid state reaction route. The crystal structures of K2MnV2O7, Rb2MnV2O7 and KRbMnV2O7 have been determined using X-ray single crystal diffraction data. The compound K2MnV2O7 crystallizes with a melilite-type structure with tetragonal unit cell parameters a = 8.609(3), c = 5.538(4) Å and space group P4̅21m. The structures of Rb2MnV2O7 and KRbMnV2O7 are derived from the melilite-type structure with space group P4̅2/mnm and unit cell parameters a = 8.577(6), c = 11.809(6) Å , and a = 8.530(6), c = 11.466(5) Å , respectively. The three structures consist of [MnV2O7]2− layers perpendicular to the c axis separated by A+ layers. The [MnV2O7]2− layers feature corner-sharing MnO4 tetrahedra and V2O7 pyrovanadate units, the linkage leading to rings of five tetrahedra. The doubling of the c parameter for Rb2MnV2O7 or RbKMnV2O7 is explained by the existence of a mirror plane perpendicular to the [001] direction between two [MnV2O7]2− layers. The A+ alkali cations occupy distorted square antiprisms of oxygen atoms in K2MnV2O7 and distorted square prisms of oxygen atoms in Rb2MnV2O7and RbKMnV2O7.


2014 ◽  
Vol 70 (11) ◽  
pp. 1468-1471
Author(s):  
Trung Thanh Thach ◽  
Sangho Lee

Adenylate kinases (AdKs; EC 2.7.3.4) play a critical role in intercellular homeostasis by the interconversion of ATP and AMP to two ADP molecules. Crystal structures of adenylate kinase fromStreptococcus pneumoniaeD39 (SpAdK) have recently been determined using ligand-free and inhibitor-bound crystals belonging to space groupsP21andP1, respectively. Here, new crystal structures of SpAdK in ligand-free and inhibitor-bound states determined at 1.96 and 1.65 Å resolution, respectively, are reported. The new ligand-free crystal belonged to space groupC2, with unit-cell parametersa= 73.5,b= 54.3,c= 62.7 Å, β = 118.8°. The new ligand-free structure revealed an open conformation that differed from the previously determined conformation, with an r.m.s.d on Cαatoms of 1.4 Å. The new crystal of the complex with the two-substrate-mimicking inhibitorP1,P5-bis(adenosine-5′-)pentaphosphate (Ap5A) belonged to space groupP1, with unit-cell parametersa= 53.9,b= 62.3,c= 63.0 Å, α = 101.9, β = 112.6, γ = 89.9°. Despite belonging to the same space group as the previously reported crystal, the new Ap5A-bound crystal contains four molecules in the asymmetric unit, compared with two in the previous crystal, and shows slightly different lattice contacts. These results demonstrate that SpAdK can crystallize promiscuously in different forms and that the open structure is flexible in conformation.


1998 ◽  
Vol 54 (3) ◽  
pp. 211-220 ◽  
Author(s):  
R. P. Hammond ◽  
J. Barbier

Hexagonal (Na3/4K1/4)AlGeO4 crystallizes in the space group P63 with unit-cell parameters a = 10.164 (2), c = 8.540 (2) Å and Z = 8 [wR(F 2) = 0.066 for all 3060 independent reflections]. Monoclinic (Na3/4K1/4)AlGeO4 crystallizes in the space group P21 with unit-cell parameters a = 10.0477 (4), b = 8.5764 (4), c = 10.2118 (4) Å, β = 119.035 (1)° and Z = 8 [wR(F 2) = 0.120 for all 3194 independent reflections measured on a twinned crystal]. Both structures belong to the large family of stuffed tridymites, with the Al and Ge atoms occupying tetrahedral sites, and the alkali atoms occupying the cavities of the tetrahedral framework. Hexagonal (Na3/4K1/4)AlGeO4 is isostructural with the silicate mineral nepheline (Na3/4K1/4)AlSiO4, while monoclinic (Na3/4K1/4)AlGeO4 corresponds to a minor distortion of the nepheline structure. Chemical analysis by electron microprobe and structure determination of flux-grown single crystals indicate that the hexagonal form with the chemical formula (Na0.78K0.19)Al0.97Ge1.03O4 may be stabilized by an alkali deficiency similar to that found in hexagonal natural nephelines. In contrast, all alkali sites are fully occupied in the monoclinic form of composition (Na0.75K0.25)AlGeO4 and the lower symmetry eliminates the oxygen disorder present in the hexagonal form.


2021 ◽  
pp. 1-3
Author(s):  
J. Maixner ◽  
J. Ryšavý

X-ray powder diffraction data, unit-cell parameters, and space group for tetrazene nitrate monohydrate, C2H9N11O4, are reported [a = 5.205(1) Å, b = 13.932(3) Å, c = 14.196(4) Å, β = 97.826(3)°, unit-cell volume V = 1019.8(4) Å3, Z = 4, and space group P21/c]. All measured lines were indexed and are consistent with the P21/c space group. No detectable impurities were observed.


Crystals ◽  
2018 ◽  
Vol 8 (7) ◽  
pp. 299 ◽  
Author(s):  
Krzysztof Konieczny ◽  
Arkadiusz Ciesielski ◽  
Julia Bąkowicz ◽  
Tomasz Galica ◽  
Ilona Turowska-Tyrk

We studied the photochemical reactivity of salts of 4-(2,4,6-triisopropylbenzoyl)benzoic acid with propane-1,2-diamine (1), methanamine (2), cyclohexanamine (3), and morpholine (4), for compounds (1), (3), and (4) at 0.1 MPa and for compounds (1) and (2) at 1.3 GPa and 1.0 GPa, respectively. The changes in the values of the unit cell parameters after UV irradiation and the values of the intramolecular geometrical parameters indicated the possibility of the occurrence of the Norrish–Yang reaction in the case of all the compounds. The analysis of the intramolecular geometry and free spaces revealed which o-isopropyl group takes part in the reaction. For (1), the same o-isopropyl group should be reactive at ambient and high pressures. In the case of (2), high pressure caused the phase transition from the space group I2/a with one molecule in the asymmetric unit cell to the space group P1¯ with two asymmetric molecules. The analysis of voids indicated that the Norrish–Yang reaction is less probable for one of the two molecules. For the other molecule, the intramolecular geometrical parameters showed that except for the Norrish–Yang reaction, the concurrent reaction leading to the formation of a five-membered ring can also proceed. In (3), both o-isopropyl groups are able to react; however, the bigger volume of a void near 2-isopropyl may be the factor determining the reactivity. For (4), only one o-isopropyl should be reactive.


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

Phytases are phosphatases that hydrolyze phytates to less phosphorylatedmyo-inositol derivatives and inorganic phosphate. β-Propeller phytases, which are very diverse phytases with improved thermostability that are active at neutral and alkaline pH and have absolute substrate specificity, are ideal substitutes for other commercial phytases. PhyH-DI, a β-propeller phytase fromBacillussp. HJB17, was found to act synergistically with other single-domain phytases and can increase their efficiency in the hydrolysis of phytate. Crystals of native and selenomethionine-substituted PhyH-DI were obtained using the vapour-diffusion method in a condition consisting of 0.2 Msodium chloride, 0.1 MTris pH 8.5, 25%(w/v) PEG 3350 at 289 K. X-ray diffraction data were collected to 3.00 and 2.70 Å resolution, respectively, at 100 K. Native PhyH-DI crystals belonged to space groupC121, with unit-cell parametersa = 156.84,b = 45.54,c = 97.64 Å, α = 90.00, β = 125.86, γ = 90.00°. The asymmetric unit contained two molecules of PhyH-DI, with a corresponding Matthews coefficient of 2.17 Å3 Da−1and a solvent content of 43.26%. Crystals of selenomethionine-substituted PhyH-DI belonged to space groupC2221, with unit-cell parametersa = 94.71,b= 97.03,c= 69.16 Å, α = β = γ = 90.00°. The asymmetric unit contained one molecule of the protein, with a corresponding Matthews coefficient of 2.44 Å3 Da−1and a solvent content of 49.64%. Initial phases for PhyH-DI were obtained from SeMet SAD data sets. These data will be useful for further studies of the structure–function relationship of PhyH-DI.


1999 ◽  
Vol 55 (4) ◽  
pp. 907-909 ◽  
Author(s):  
Jun Masuda ◽  
Tetsuya Yamaguchi ◽  
Takamasa Tobimatsu ◽  
Tetsuo Toraya ◽  
Kyoko Suto ◽  
...  

Two crystal forms of Klebsiella oxytoca diol dehydratase complexed with cyanocobalamin have been obtained and preliminary crystallographic experiments have been performed. The crystals belong to two different space groups, depending on the crystallization conditions. One crystal (form I) belongs to space group P212121 with unit-cell parameters a = 76.2, b = 122.3, c = 209.6 Å, and diffracts to 2.2 Å resolution using an X-ray beam from a synchrotron radiation source. The other crystal (form II) belongs to space group P21 with unit-cell parameters a = 75.4, b = 132.7, c = 298.8 Å, β = 91.9°, and diffracts to 3.0 Å resolution. For the purpose of structure determination, a heavy-atom derivative search was carried out and some mercuric derivatives were found to be promising. Structure analysis by the multiple isomorphous replacement method is now under way.


2017 ◽  
Vol 32 (3) ◽  
pp. 203-205
Author(s):  
Xiang Lin ◽  
Wei Ling Zhuo ◽  
Qiao Hong Du ◽  
Xi Lin Peng ◽  
Hui Li

X-ray powder diffraction data, unit-cell parameters, and space group for ertapenem side chain, C20H19N3O7S, are reported [a = 4.907(6) Å, b = 18.686(3) Å, c = 22.071(1) Å, α = γ = 90°, β = 90.759(5)°, unit-cell volume V = 2023.82 Å3, Z = 4, ρcal = 1.462 g cm−3, and space group P21/c]. All measured lines were indexed and are consistent with the P21/c space group. No detectable impurity was observed.


2013 ◽  
Vol 28 (4) ◽  
pp. 296-298
Author(s):  
R. Pažout ◽  
J. Maixner ◽  
A.S. Jones ◽  
J. Merna

X-ray powder diffraction data, unit-cell parameters, and space group for a new bis(β-diiminato) Cu(II) complex, C44H54CuN4O4, are reported [a = 8.683(3) Å, b = 11.216(3) Å, c = 11.753(4) Å, α = 66.27(3), β = 84.61(3), γ = 78.85(3), unit-cell volume V = 1027.77 Å3, Z = 1, and space group P-1]. All measured lines were indexed and are consistent with the P-1 space group. No detectable impurity was observed.


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