Armstrongite from the Strange Lake Alkalic Complex, on the Quebec – Labrador Boundary, Canada

1987 ◽  
Vol 2 (1) ◽  
pp. 2-4 ◽  
Author(s):  
John L. Jambor ◽  
Andrew C. Roberts ◽  
Joel D. Grice

AbstractTabular untwinned crystals of colorless transparent armstrongite from the Strange Lake Alkalic Complex, on the Quebec – Labrador boundary, Canada are monoclinic, space group choices I2/m, I2, Im (diffraction aspect I*/*), with refined unit-cell parameters a = 13.599 (9), b = 14.114(9), c = 7.833 (4) Å, β = 103.41 (5)°, V = 1462.4 (±3.0) Å3. a:b:c = 0.9635:1:0.5550, Z = 4 and D(x) = 2.696 g/cm3. A fully indexed X-ray powder pattern is presented. Averaged electron-microprobe analyses suggest a theoretical formula of CaZrSi6O15 · 3 H2O. The Strange Lake armstrongite is biaxial negative, α = 1.567 (1), β = 1.576 (1), γ = 1.577 (1), 2V (meas.) = 39 (1)°, 2V (calc.) = 37°, Z∥b, X Λc = +4°, with no absorption and weak dispersion r < v.

1986 ◽  
Vol 1 (1) ◽  
pp. 56-57 ◽  
Author(s):  
Andrew C. Roberts ◽  
John L. Jambor ◽  
Joel D. Grice

AbstractCrystals of green to bluish green rosasite from Tsumeb, Namibia are monoclinic, space group P21/a, with refined unit-cell parameters a = 12.873 (3), b = 9.354 (3), c = 3.156 (2) A, β = 110.36 (3)°, V = 356.3 (5) A3 and a:b:c = 1.3762:1:0.3374, with Z = 4 and Dx = 4.15 g./cm.3. Crystals are twinned by 180° rotation about a*. A fully indexed powder pattern is presented. Electron-microprobe analyses, average (wt. %): Cu 32.9, Zn 23.7; this suggests an analytical formula of (Cu1·18 Zn0·82) (CO3) (OH)2. The rosasite is optically biaxial negative, α = 1.673 (1), β = 1.796 (3), γ = 1.811 (3), 2Vx = 33 (5)° (calc. 36.4°), with X = c, Y = a* and Z = b.


1999 ◽  
Vol 55 (11) ◽  
pp. 1928-1929 ◽  
Author(s):  
Junichi Komoto ◽  
Yafei Huang ◽  
Yongbo Hu ◽  
Yoshimi Takata ◽  
Kiyoshi Konishi ◽  
...  

Guanidinoacetate methyltransferase is the enzyme which catalyzes the last step of creatine biosynthesis. The enzyme is found ubiquitously and in abundance in the livers of all vertebrates. Recombinant rat-liver guanidinoacetate methyltransferase has been crystallized with guanidinoacetate and S-adenosylhomocysteine. The crystals belong to the monoclinic space group P21, with unit-cell parameters a = 54.8, b = 162.5, c = 56.1 Å, β = 96.8 (1)° at 93 K, and typically diffract beyond 2.8 Å.


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.


2014 ◽  
Vol 70 (10) ◽  
pp. 1389-1393 ◽  
Author(s):  
Mulu Y. Lubula ◽  
Amanda Poplawaski ◽  
Karen C. Glass

The bromodomain-PHD finger protein 1 (BRPF1) is an essential subunit of the monocytic leukemia zinc (MOZ) histone acetyltransferase (HAT) complex and is required for complex formation and enzymatic activation. BRPF1 contains a structurally conserved bromodomain, which recognizes specific acetyllysine residues on histone proteins. The MOZ HAT plays a direct role in hematopoiesis, and deregulation of its activity is linked to the development of acute myeloid leukemia. However, the molecular mechanism of histone-ligand recognition by the BRPF1 bromodomain is currently unknown. The 117-amino-acid BRPF1 bromodomain was overexpressed inEscherichia coliand purified to homogeneity. Crystallization experiments of the BRPF1 bromodomain in complex with its H4K12ac and H2AK5ac histone ligands yielded crystals that were suitable for high-resolution X-ray diffraction analysis. The BRPF1 bromodomain–H4K12ac crystals belonged to the tetragonal space groupP43212, with unit-cell parametersa= 75.1,b= 75.1,c= 86.3 Å, and diffracted to a resolution of 1.94 Å. The BRPF1 bromodomain–H2AK5ac crystals grew in the monoclinic space groupP21, with unit-cell parametersa= 60.9,b= 55.6,c= 82.1 Å, β = 93.6°, and diffracted to a resolution of 1.80 Å. Complete data sets were collected from both crystal forms using synchrotron radiation on beamline X29 at Brookhaven National Laboratory (BNL).


1994 ◽  
Vol 9 (2) ◽  
pp. 98-104
Author(s):  
Jaakko Leppä-aho ◽  
Jussi Valkonen

X-ray powder diffraction data are reported for a series of isomorphous compounds of [Ln2(CrO4)3(H2O)5]·2H2O, where Ln=La, Pr, Nd, Sm, or Eu. The compounds crystallize in monoclinic space group P21/c (No: 14) with Z=4. Refined unit cell parameters and indexed powder diffraction patterns are given.


2009 ◽  
Vol 64 (5) ◽  
pp. 565-569 ◽  
Author(s):  
Saied Ghadimi ◽  
Mehrdad Pourayoubi ◽  
Ali Asghar Ebrahimi Valmoozi

Mixed diamidophosphoric acid esters [(CH3)2N][p-H3C-C6H4-O]P(O)X, where X = NH(CH3) (1), NHCH(CH3)2 (2), NHC(CH3)3 (3) and p-H3C-C6H4-NH (4) were synthesized and characterized by 31P, 31P{1H}, 13C, 1H NMR, and IR spectroscopy and mass spectrometry, and single crystal X-ray diffraction analysis for the compounds 3 and 4. Compound 3 crystallizes in the monoclinic, space group P21/c with unit cell parameters a = 9.006(3), b = 16.286(5), c = 10.319(3) A° , β = 99.633(6)◦, V = 1492.2(8) °A3, Z = 4. The final R value is 0.0622 for 2074 reflections [I ≥ 2σ (I)]. Compound 4 crystallizes in the orthorhombic, space group Pna21 with unit cell parameters a = 7.0459(14), b = 20.934(4), c = 10.436(2) ° A, V = 1539.3(5) °A3, Z = 4. The final R value is 0.0530 for 3025 reflections [I ≥ 2σ (I)].


Author(s):  
Xavier Kubiak ◽  
Benjamin Pluvinage ◽  
Inès Li de la Sierra-Gallay ◽  
Patrick Weber ◽  
Ahmed Haouz ◽  
...  

ArylamineN-acetyltransferases (NATs) are xenobiotic metabolizing enzymes (XMEs) that catalyze the acetylation of arylamines. All functional NATs described to date possess a strictly conserved Cys-His-Asp catalytic triad. Here, the purification, crystallization and preliminary X-ray characterization ofBacillus cereusarylamineN-acetyltransferase 3 [(BACCR)NAT3], a putative NAT isoenzyme that possesses a unique catalytic triad containing a glutamate residue, is reported. The crystal diffracted to 2.42 Å resolution and belonged to the monoclinic space groupC121, with unit-cell parametersa= 90.44,b= 44.52,c = 132.98 Å, β = 103.8°.


2019 ◽  
Vol 10 (3) ◽  
pp. 201-208
Author(s):  
Pokpa Haba ◽  
Adama Sy ◽  
Farba Bouyagui Tamboura ◽  
Mamour Sarr ◽  
Ibrahima Elhadji Thiam ◽  
...  

Reactions of the Schiff base N,N-dimethyl-N'-((5-methyl-1H-imidazol-4-yl)methylene) ethane-1,2-diamine (HL), synthesised in situ, with chloride or thiocyanate copper (II) salt; afforded two new mononuclear complexes, [Cu(HL)Cl2]·H2O (1) and [Cu(HL)(SCN)2] (2). These compounds have been studied and characterized by elemental analysis, IR and UV-Vis spectroscopies, electrochemistry, molar conductivity and room temperature magnetic measurements. Single crystal X-ray structure determination of the complexes revealed the presence of neutral moieties in the asymmetric unit. The mononuclear (1) crystallises in the monoclinic space group P21/c with the following unit cell parameters a = 7.4355(3) Å, b = 7.2952(3) Å, c = 26.2729(11) Å, β = 93.461(4)°, V = 1422.52(10) Å3, Z = 4, R1 = 0.033 and wR2 = 0.082 and the mononuclear complex (2) crystallises in the monoclinic space group C2/c with the following unit cell parameters a = 26.2578(7) Å, b = 7.4334(2) Å, c = 16.6237(5) Å, β = 99.089(3)°, V = 3203.95(16) Å3, Z = 8, R1 = 0.037 and wR2 = 0.104. In both complexes the ligand acts in tridentate fashion and the coordination environment of the copper atom can be described as distorted square pyramidal. The crystal lattice of the complex 1 is stabilized by electrostatic forces of attraction and O–H···Cl, C–H···O, N–H···Cl, and C–H···Cl, hydrogen bonding interactions while the crystal lattice of the complex 2 is stabilized by N–H···S and C–H···N.


2021 ◽  
Vol 12 (2) ◽  
pp. 2586-2602

The triphosphate dodecahydrate of cobalt and sodium CoNa3P3O10.12H2O was prepared by the ion exchange resin process. Its structure was studied by X-ray diffraction and determined in the monoclinic space group P121/c1with the unit-cell parameters a = 14.6650(5) Å, b=9.1916(3) Å, c = 15.0239(5) Å, =90.2210(10) °, Z = 4 and V = 2025.13(12) Å3. The thermal dehydration of this compound was performed, leading to an anhydrous new form, CoNa3P3O10, which was characterized by X-ray diffraction. The obtained CoNa3P3O10 crystallized in monoclinic space group P21/n with the unit-cell parameters a=15,3774 Å, b=7,6988 A°, c=14,2832A°, β=92,9115°.The characteristic IR wavenumbers of the P3O105− ions observed in the vibrational spectra were calculated using isotopic substitutions, which confirms the existence of these groups in the studied compound. A comparison between the IR and Raman wavenumbers of CoNa3P3O10.12H2O, CoNa3P3O10 and Na5P3O10.12H2O was performed. A kinetic study was also made for CoNa3P3O10·12H2O.


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 ◽  
...  

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.


Sign in / Sign up

Export Citation Format

Share Document