Olivenite and cornwallite from the Podlipa copper deposit near Ľubietová, Slovakia

2021 ◽  
Vol 29 (2) ◽  
pp. 189-196
Author(s):  
Martin Števko ◽  
Jiří Sejkora ◽  
Zdeněk Dolníček

An interesting occurrence of olivenite and cornwallite was recently discovered in cavities of quartz at the Podlipa copper deposit near Ľubietová, Slovakia. Olivenite occurs as olive to pale green sprays or radial aggregates consisting of individual acicular crystals up to 5 mm long. Its refined unit-cell parameters (for the monoclinic space group P21/n) are: a 8.6192(13) Å, b 8.2300(11) Å, c 5.9349(8) Å, α 90.055(12)° and V 420.99(7) Å3. Studied olivenite shows intense chemical zoning caused by strong variation of As and P contents. Most of the zones are corresponding to olivenite (with P content ranging between 0.02 to 0.39 apfu), but darker zones or domains of As-rich libethenite (with As content ranging between 0.18 to 0.24 apfu) were occasionally observed. Cornwallite forms dark green massive fillings between olivenite crystals or microcrystalline botryoidal crusts. The refined unit-cell parameters (for the monoclinic space group P21/c) of botryoidal cornwallite from the Podlipa deposit are: a 4.6112(2) Å, b 5.7698(3) Å, c 17.4167(11) Å, β 92.009(5)° and V 463.10(3) Å3. The two compositional types of cornwallite were distinguished. The first type is represented by relatively homogenous aggregates with only minor contents of P (from 0.04 to 0.22 apfu). The second type occurs as polycrystalline fillings with strong chemical zoning and has much more significant variation of As and P contents, representing solid-solution series between P-rich cornwallite (with 1.41 apfu of As and 0.59 apfu of P) and As-rich pseudomalachite (with 1.37 apfu of P and 0.63 apfu of As).

2020 ◽  
Vol 28 (2) ◽  
pp. 290-294
Author(s):  
Martin Števko ◽  
Jiří Sejkora ◽  
Zdeněk Dolníček

A new occurrence of pseudomalachite was recently discovered at the Zadné Breziny copper occurrence near Gemerská Poloma, Rožňava Co., Košice Region, Slovakia. It forms dark green rich coatings and crusts, which consist of individual hemispherical aggregates up to 7 mm in size. Pseudostalactites up to 6 mm in size were also rarely observed. Pseudomalachite occurs in fractures and cavities of the quartz gangue or in fractures of the wall rock. It is associated with malachite, cuprite and native copper. The refined unit-cell parameters (for the monoclinic space group P21/c) are a 4.4805(5) Å, b 5.7504(6) Å, c 17.045(2) Å, β 91.12(1)° and V 439.06(6) Å3. Except of dominant contents of Cu and P only minor amounts of Al (up to 0.04 apfu), Fe (up to 0.02 apfu), As (up to 0.07 apfu) and S (up to 0.01 apfu) were detected in studied samples of pseudomalachite from the Zadné Breziny occurrence.


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.


Author(s):  
Analio Dugarte-Dugarte ◽  
Nahum Ramírez Pineda ◽  
Luis Nieves ◽  
José Antonio Henao ◽  
Graciela Díaz de Delgado ◽  
...  

Almost 50 years after the initial report, the crystal structure of Cu2GeSe3, a I2-IV-VI3 semiconductor, has been revised using modern single-crystal X-ray diffraction data. The structure of this material can be properly described in the monoclinic space group Cc (No. 9) with unit-cell parameters a = 6.7703 (4) Å, b = 11.8624 (5) Å, c = 6.7705 (4) Å, β = 108.512 (6)°, V = 515.62 (5) Å3, Z = 4, rather than in the orthorhombic space group Imm2 (No. 44) with unit-cell parameters a = 11.860 (3), b = 3.960 (1), c = 5.485 (2) Å, V = 257.61 Å3, Z = 2, as originally proposed [Parthé & Garín (1971). Monatsh. Chem. 102, 1197–1208]. Contrary to what was observed in the orthorhombic structure, the distortions of the tetrahedra in the monoclinic structure are consistent with the distortions expected from considerations derived from the bond valence model. A brief revision of the structures reported for the I2-IV-VI3 family of semiconducting compounds (I: Cu, Ag; IV: Si, Ge, Sn; and VI: S, Se, Te) is also presented.


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.


Author(s):  
A. D. Fortes ◽  
J. Ponsonby ◽  
O. Kirichek ◽  
V. García-Sakai

Neutron powder diffraction data have been collected from a series of flash-frozen aqueous solutions of dimethyl sulfoxide (DMSO) with concentrations between 25 and 66.7 mol% DMSO. These reveal the existence of three stoichiometric hydrates, which crystallize on warming between 175 and 195 K. DMSO trihydrate crystallizes in the monoclinic space group P21/c, with unit-cell parameters at 195 K of a = 10.26619 (3), b = 7.01113 (2), c = 10.06897 (3) Å, β = 101.5030 (2)° and V = 710.183 (3) Å3 (Z = 4). Two of the symmetry-inequivalent water molecules form a sheet of tiled four- and eight-sided rings; the DMSO molecules are sandwiched between these sheets and linked along the b axis by the third water molecule to generate water–DMSO–water tapes. Two different polymorphs of DMSO dihydrate have been identified. The α phase is monoclinic (space group P21/c), with unit-cell parameters at 175 K of a = 6.30304 (4), b = 9.05700 (5), c = 11.22013 (7) Å, β = 105.9691 (4)° and V = 615.802 (4) Å3 (Z = 4). Its structure contains water–DMSO–water chains, but these are polymerized in such a manner as to form sheets of reniform eight-sided rings, with the methyl groups extending on either side of the sheet. On warming above 198 K, α-DMSO·2H2O undergoes a solid-state transformation to a mixture of DMSO·3H2O + anhydrous DMSO, and there is then a stable eutectic between these two phases at ∼203 K. The β-phase of DMSO dihydrate has been observed in a rapidly frozen eutectic melt and in very DMSO-rich mixtures. It is observed to be unstable with respect to the α-phase; above ∼180 K, β-DMSO·2H2O converts irreversibly to α-DMSO·2H2O. At 175 K, the lattice parameters of β-DMSO·2H2O are a = 6.17448 (10), b = 11.61635 (16), c = 8.66530 (12) Å, β = 101.663 (1)° and V = 608.684 (10) Å3 (Z = 4), hence this polymorph is just 1.16% denser than the α-phase under identical conditions. Like the other two hydrates, the space group appears likely, on the basis of systematic absences, to be P21/c, but the structure has not yet been determined. Our results reconcile 60 years of contradictory interpretations of the phase relations in the binary DMSO–water system, particularly between mole fractions of 0.25–0.50, and confirm empirical and theoretical studies of the liquid structure around the eutectic composition (33.33 mol% DMSO).


2015 ◽  
Vol 71 (9) ◽  
pp. 1194-1199 ◽  
Author(s):  
Hugo Serrano-Posada ◽  
Sara Centeno-Leija ◽  
Sonia Rojas-Trejo ◽  
Vivian Stojanoff ◽  
Romina Rodríguez-Sanoja ◽  
...  

Labdane-related diterpenoids are natural products with potential pharmaceutical applications that are rarely found in bacteria. Here, a putative class I labdane-related diterpene synthase (LrdC) identified by genome mining in a streptomycete was successfully crystallized using the microbatch method. Crystals of the LrdC enzyme were obtained in a holo form with its natural cofactor Mg2+(LrdC-Mg2+) and in complex with inorganic pyrophosphate (PPi) (LrdC-Mg2+–PPi). Crystals of native LrdC-Mg2+diffracted to 2.50 Å resolution and belonged to the trigonal space groupP3221, with unit-cell parametersa = b = 107.1,c= 89.2 Å. Crystals of the LrdC-Mg2+–PPicomplex grown in the same conditions as the native enzyme with PEG 8000 diffracted to 2.36 Å resolution and also belonged to the trigonal space groupP3221. Crystals of the LrdC-Mg2+–PPicomplex grown in a second crystallization condition with PEG 3350 diffracted to 2.57 Å resolution and belonged to the monoclinic space groupP21, with unit-cell parametersa= 49.9,b= 104.1,c= 66.5 Å, β = 111.4°. The structure was determined by the single-wavelength anomalous dispersion (SAD) technique using the osmium signal from a potassium hexachloroosmate (IV) derivative.


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)].


Crystals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 955
Author(s):  
Saeed Alshahrani ◽  
Saied M. Soliman ◽  
Abdullah Saleh Alamary ◽  
Abdullah Mohammed Al-Majid ◽  
Matti Haukka ◽  
...  

(E)-1-(1H-Benzo[d]imidazol-2-yl)-3-(dimethylamino)prop-2-en-1-one 2 was synthesized by one-pot synthesis protocol of 2-acetyl benzo[d]imidazole with dimethylformamide dimethylacetal (DMF-DMA) in xylene at 140 °C for 8 h. Reaction of enaminone derivative 1 with acetylacetone in the presence of AcOH/NH4OAc under reflux afforded the cyclized pyridino-benzo[d]imidazole derivative 3. The latter compound was converted into the corresponding β-enaminone 4 with DMF-DMA. The single crystal X-ray diffraction technique eventually confirmed the assigned chemical structure of the N-alkyl-β-enaminone 2 and pyridino-benzo[d]imidazole derivative 3. N-alkyl-β-enaminone 2 crystallized in the monoclinic space group P21/n with unit cell parameters of a = 9.8953(3) Å, b = 5.7545(2) Å, c = 21.7891(7) Å, and β =100.627(2)°, and with one molecule per asymmetric unit. On the other hand, compound 3 crystallized in the orthorhombic crystal system and space group P212121 with unit cell parameters of a = 6.82950(10) Å, b = 8.00540(10) Å, c = 22.4779(2) Å, and also with one molecule per asymmetric unit. Based on Hirshfeld analysis, the H...H (51.3%), O...H (10.0%), N...H (10.3%), and C...H (27.6%) contacts in 2 and the H...H (46.8%), O...H (9.9%), N...H (13.0%), and C...H (21.6%) in addition to the C…C (6.7%) interactions in 3 are the most important towards crystal stability via molecular packing. The main difference is the presence of π–π interaction among the molecular units of 3 but not in 2. The calculated 1H and 13C NMR chemical shifts showed good agreements with experimental data. Electronic properties and reactivity parameters of both compounds are also calculated and compared.


Sign in / Sign up

Export Citation Format

Share Document