Molecular and Crystal Structure of Sildenafil Base

2012 ◽  
Vol 67 (5) ◽  
pp. 491-494 ◽  
Author(s):  
Dmitrijs Stepanovs ◽  
Anatoly Mishnev

Sildenafil citrate monohydrate, well known as Viagra®, is a drug for the treatment of erectile dysfunction. Here we present the X-ray crystal structure of the sildenafil base, C22H30N6O4S. The compound crystallizes in the monoclinic system, space group P21/c with the unit cell parameters a = 17:273(1), b=17:0710(8), c=8:3171(4) Å , b =99:326(2), Z = 4, V = 2420:0(3) Å3. A comparison with the known crystal structures of sildenafil citrate monohydrate and sildenafil saccharinate is also presented.

Minerals ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 486 ◽  
Author(s):  
Andrey A. Zolotarev ◽  
Elena S. Zhitova ◽  
Maria G. Krzhizhanovskaya ◽  
Mikhail A. Rassomakhin ◽  
Vladimir V. Shilovskikh ◽  
...  

The technogenic mineral phases NH4MgCl3·6H2O and (NH4)2Fe3+Cl5·H2O from the burned dumps of the Chelyabinsk coal basin have been investigated by single-crystal X-ray diffraction, scanning electron microscopy and high-temperature powder X-ray diffraction. The NH4MgCl3·6H2O phase is monoclinic, space group C2/c, unit cell parameters a = 9.3091(9), b = 9.5353(7), c = 13.2941(12) Å, β = 90.089(8)° and V = 1180.05(18) Å3. The crystal structure of NH4MgCl3·6H2O was refined to R1 = 0.078 (wR2 = 0.185) on the basis of 1678 unique reflections. The (NH4)2Fe3+Cl5·H2O phase is orthorhombic, space group Pnma, unit cell parameters a = 13.725(2), b = 9.9365(16), c = 7.0370(11) Å and V = 959.7(3) Å3. The crystal structure of (NH4)2Fe3+Cl5·H2O was refined to R1 = 0.023 (wR2 = 0.066) on the basis of 2256 unique reflections. NH4MgCl3·6H2O is stable up to 90 °C and then transforms to the less hydrated phase isotypic to β-Rb(MnCl3)(H2O)2 (i.e., NH4MgCl3·2H2O), the latter phase being stable up to 150 °C. (NH4)2Fe3+Cl5·H2O is stable up to 120 °C and then transforms to an X-ray amorphous phase. Hydrogen bonds provide an important linkage between the main structural units and play the key role in determining structural stability and physical properties of the studied phases. The mineral phases NH4MgCl3·6H2O and (NH4)2Fe3+Cl5·H2O are isostructural with natural minerals novograblenovite and kremersite, respectively.


2018 ◽  
Vol 33 (3) ◽  
pp. 216-224 ◽  
Author(s):  
V. D. Zhuravlev ◽  
A. P. Tyutyunnik ◽  
A. Y. Chufarov ◽  
N. I. Lobachevskaya ◽  
A. A. Velikodnyi

Polycrystalline samples of Ca2Zn2(V4O14) (I) and Pb2Cd2(V3O10)(VO4) (II) were synthesized using the nitrate–citrate method (I) and conventional solid state reaction (II). The structural refinement based on X-ray powder diffraction data showed that the crystal structure of (I) is characterized by monoclinic symmetry with unit-cell parameters a = 6.8044(1) Å, b = 14.4876(3) Å, c = 11.2367(2) Å, β = 99.647(1)° [space group P21/c (No. 14), Z = 4], and the crystal structure of (II) is triclinic with unit-cell parameters a = 7.03813(6) Å, b = 12.9085(1) Å, c = 6.99961(5) Å, α = 90.7265(5)°, β = 96.3789(5)°, γ = 94.9530(6)°, V = 629.470(8) Å3 [space group P$\bar 1$ (No. 2), Z = 2].


2018 ◽  
Vol 33 (1) ◽  
pp. 62-65
Author(s):  
Martin Etter

Commercially available trisodium hexachlororhodate (Na3RhCl6) was dehydrated and characterized by laboratory X-ray powder diffraction. The crystal structure is isostructural to the Na3CrCl6 structure type with space group P$\bar 31$c. Unit-cell parameters are a = 6.8116(1) Å, c = 11.9196(2) Å, V = 478.95(2) Å3, and Z = 2.


2019 ◽  
Vol 65 (4 Jul-Aug) ◽  
pp. 360 ◽  
Author(s):  
G. E. Delgado ◽  
C. Rincón ◽  
G. Marroquin

The crystal structure of the ordered vacancy compound (OVC) Cu3In5Te9 was analyzed using powder X-ray diffraction data. Several structural models were derived from the structure of the Cu-poor Cu-In-Se compound b-Cu0.39In1.2Se2 by permuting the cations in the available site positions. The refinement of the best model by the Rietveld method in the tetragonal space group P2c (Nº 112), with unit cell parameters a = 6.1852(2) Å, c = 12.3633(9) Å, V = 472.98(4) Å3, led to Rp = 7.1 %, Rwp = 8.5 %, Rexp = 6.4 %, S = 1.3 for 162 independent reflections. This model has the following Wyckoff site atomic distribution: Cu1 in 2e (0,0,0); In1 in 2f (½,½,0), In2 in 2d (0,½,¼); Cu2-In3 in 2b (½,0,¼); in 2a (0,0,¼); Te in 8n (x,y,z).


2021 ◽  
Vol 33 (6) ◽  
pp. 717-726
Author(s):  
Daniela Mauro ◽  
Cristian Biagioni ◽  
Federica Zaccarini

Abstract. Gersdorffite, ideally NiAsS, and associated minerals from Contrada Zillì (Peloritani Mountains, Sicily, Italy) have been characterized through electron microprobe analysis and X-ray diffraction. Primary minerals, hosted in quartz veins, are represented by gersdorffite, tetrahedrite-(Fe), and chalcopyrite with minor pyrite and galena. Rare aikinite inclusions were observed in tetrahedrite-(Fe) and chalcopyrite. Gersdorffite occurs as euhedral to subhedral crystals, up to 1 mm in size, with (Sb,Bi)-enriched cores and (Fe,As)-enriched rims. Its chemical composition is (Ni0.79−0.95Fe0.18−0.04Co0.04−0.01)(As0.90−1.03Sb0.10−0.00Bi0.02−0.00)S0.98−0.92. It crystallizes in the space group P213, with unit-cell parameters a=5.6968(7) Å, V=184.88(7) Å3, and Z=4, and its crystal structure was refined down to R1= 0.035. Associated tetrahedrite-(Fe) has chemical formula (Cu5.79Ag0.07)Σ5.86(Cu3.96Fe1.59Zn0.45)Σ6.00(Sb3.95As0.17Bi0.03)Σ4.15S13.06, with unit-cell parameters a= 10.3815(10) Å, V=1118.9(3) Å3, and space group I-43m. Its crystal structure was refined to R1=0.027. Textural and crystallographic data suggest a polyphasic crystallization of gersdorffite under low-temperature conditions.


Author(s):  
Dengke Tian ◽  
Xueqi Fu ◽  
Wenqiang Cao ◽  
Hong Yuan

Gluconate 5-dehydrogenase (Ga5DH; EC 1.1.1.69) from Lentibacter algarum (LaGa5DH) was recombinantly expressed in Escherichia coli and purified to homogeneity. The protein was crystallized and the crystal structure was solved at 2.1 Å resolution. The crystal belonged to the monoclinic system, with space group P1 and unit-cell parameters a = 55.42, b = 55.48, c = 79.16 Å, α = 100.51, β = 105.66, γ = 97.99°. The structure revealed LaGaDH to be a tetramer, with each subunit consisting of six α-helices and three antiparallel β-hairpins. LaGa5DH has high structural similarity to other Ga5DH proteins, demonstrating that this enzyme is highly conserved.


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.


1988 ◽  
Vol 66 (7) ◽  
pp. 1770-1775 ◽  
Author(s):  
David J. Elliot ◽  
Sanna Haukilahti ◽  
David G. Holah ◽  
Alan N. Hughes ◽  
Stanislaw Maciaszek ◽  
...  

Reactions between Co(II), Diphos, and NaBH3CN lead to Co(BH3CN)2(Diphos)2, 1, or [Co(BH3CN)(Diphos)2]X, 2 (X = ClO4 or BPh4), and, in certain solvents, 2 reacts to produce [Co(CN)(Diphos)2](ClO4). Compound 1 can be reversibly converted to Co(BH3CN)2(DMF)4, 4, via Co(BH3CN)2(Diphos)(DMF). In addition, 1 reacts with CO to form the Co(I) and Co(III) compounds [Co(Diphos)2](CO)]X and [Co(Diphos)2(CN)2]X (X = BH3CN or BPh4). Single crystal X-ray diffraction studies of 4 show that the compound crystallizes in the triclinic space group [Formula: see text], with unit cell parameters a = 7.572(6), b = 9.695(6), c = 9.395(6) Å, α = 81.06(4), β = 68.46(5), γ = 68.19(5)°, V = 595.5 Å3, Z = 1, and dcalcd = 1.202 g cm−3. The structure converged to a conventional R factor of 0.040 for 2841 observations and showed an octahedral arrangement of four O atoms from DMF molecules and two trans N-bound BH3CN groups around the Co(II) center.


2010 ◽  
Vol 25 (1) ◽  
pp. 72-74 ◽  
Author(s):  
H. A. Camargo ◽  
J. A. Henao ◽  
D. F. Amado ◽  
V. V. Kouznetsov

1-N-(4-pyridylmethyl)amino naphtalene was synthesized by means of a reaction of alpha-naphthylamine, 4-pyridylcarboxyaldehyde, in anhydrous ethanol to obtainN-(4-pyridylen)-alpha-naphthylamine and that was reduced with NaBH4 to produce the wanted compound. The X-ray powder diffraction pattern for the new compound 1-N-(4-pyrydylmethyl)amino naphtalene was obtained. This compound crystallizes in a monoclinic system with refined unit cell parameters a=10.375(5) Å, b=17.665(6) Å, c=5.566(2) Å, β=100.11(3), and V=1004.3(5) Å3, with space group P2/m (No. 10).


2014 ◽  
Vol 2014 ◽  
pp. 1-4
Author(s):  
Elango Kandasamy

Compound 1-Methyl-3-(2-pyridyl)imidazolium hexafluorophosphate was crystallized in monoclinic system with space group P21/c and unit cell parameters a=7.3740(8) Å, b=15.5931(16) Å, c=10.4787(11) Å, β= 105.3102°, and  ν=1162.12Å3. The obtained solid state structure of 1-Methyl-3-(2-pyridyl)imidazolium hexafluorophosphate shows CH⋯F type weak interactions and was analyzed.


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