scholarly journals Crystal Structures of Ethyl 4-(4-Florophenyl)-6-phenyl-2-substituted-3-pyridinecarboxylates

2014 ◽  
Vol 2014 ◽  
pp. 1-7
Author(s):  
ElSayed M. Shalaby ◽  
Aisha M. Moustafa ◽  
Adel S. Girgis ◽  
Aida M. ElShaabiny
Keyword(s):  
Crystal Structures ◽  
Piperidine Ring ◽  
Monoclinic System ◽  
Orthorhombic System ◽  
Space Group ◽  
Morpholine Ring

Three substituted pyridinecarboxylates were synthesized; (I) ethyl 2-bromo-4-4(fluorophenyl)-6-phenyl-3-pyridinecarboxylate, C20H15BrFNO2, (II) ethyl 4-(4-fluorophenyl)-2-(4-morpholinyl)-6-phenyl-3-pyridinecarboxylate, C24H23FN2O3, and (III) ethyl 4-(4-fluorophenyl)-6-phenyl-2-(1-piperidinyl)-3-pyridinecarboxylate, C25H25FN2O2. It was found that compound (I) belongs to the orthorhombic system with space group P212121, compound (II) to the monoclinic system with space group P21/c, and compound (III) to the monoclinic system with space group C2/c. The morpholine ring in (II) and piperidine ring in (III) have the shape of the distorted chair configuration.

New Quaternary Selenoantimonates AHgSbSe3 (A = Rb, Cs): Synthesis, Structures and Optical Properties

1998 ◽  
Vol 547 ◽  
Author(s):  
Zhen Chen ◽  
Ru-Ji Wang ◽  
Jing Li
Keyword(s):  
Optical Properties ◽  
Alkali Metal ◽  
Crystal Structures ◽  
Diffuse Reflectance ◽  
Layered Materials ◽  
Band Gaps ◽  
Alkali Metal Cations ◽  
Monoclinic System ◽  
Orthorhombic System ◽  
Space Group

AbstractSolvothermal reactions in ethylenediamine have resulted in two quaternary mercury containing selenoantimonates: RbHgSbSe3 (I) and CsHgSbSe3 (II). Compound I crystallizes in monoclinic system, space group P2l/c (no. 14) with a = 7.758(2)Å, b = 11.234(2)Å, c = 8.849(2) Å, β = 106.60(3)°, V = 739.1(3)Å3, Z = 4. Compound II crystallizes in orthorhombic system, space group Cmcm (no. 63) with a = 4.444(1)Å, b = 15.514(6)Å, c = 11.261(7) Å, V = 776.4(6) Å3, Z = 4. Both compounds are layered materials and their crystal structures are closely related. Both contain layers of 2[HgSbSe3-] separated by alkali-metal cations A+ (Rb, Cs). Diffuse reflectance experiments show that both compounds are semiconductors with estimated band gaps of 1.7 eV for I and 1.6 eV for II, respectively.

Crystal structures of N,N′-bis(thiophen-2-ylmethyl)ethane-1,2-diaminium hydrochloride and of its [AuCl4]− salt solved by powder diffraction

2014 ◽  
Vol 29 (3) ◽  
pp. 300-306 ◽  
Author(s):  
Silvioney A. Silva ◽  
Norberto Masciocchi ◽  
Alexandre Cuin
Keyword(s):  
Aqueous Solution ◽  
Schiff Base ◽  
Crystal Structures ◽  
Powder Diffraction ◽  
Monoclinic System ◽  
Orthorhombic System ◽  
Analytical Characterization ◽  
Space Group ◽  
Cell Parameters ◽  
Hcl Solution

Preparation, analytical characterization, and crystal structures of N,N′-bis(thiophen-2-ylmethyl)ethane-1,2-diaminium hydrochloride (1) and of its gold derivative, N,N′-bis(thiophen-2-ylmethyl)ethane-1,2-diaminium tetrachloroaurate(III) (2) are reported. Compound (1) was obtained by reduction of the Schiff base N,N′-bis(thiophen-2-ylmethyl)ethane-1,2-diamine followed by HCl solution addition, whereas compound (2) was prepared reacting (1) with K[AuCl4] in aqueous solution. Compound (1) crystallizes in the orthorhombic system with space group Iba2 and cell parameters a = 29.856(1), b = 5.1372(2), and c = 10.1635(4) Å. Crystals of (2) belong to the monoclinic system with space group P21/c and cell parameters a = 11.0829(1), b = 9.5852(1), c = 11.6054(2) Å, and β = 75.49(1)°. Both structures contain diprotonated organic moieties, counterbalanced by hydrogen-bonded Cl−, or [AuCl4]− ions, in compounds (1) and (2), respectively.

Dimere und polymere Pnictidostannat(IV)-Anionen -Darstellung und Kristallstrukturen von Na2K3[SnP3], Na2Cs3[SnP3] und Na2K3[SnBi3] / Dimeric and Polymeric Pnictidostannate(IV) Anions -Preparation and Crystal Structures of Na2K3[SnP3], Na2Cs3[SnP3] and Na2K3[SnBi3]

1998 ◽  
Vol 53 (4) ◽  
pp. 405-410 ◽  
Author(s):  
Matthias Asbrand ◽  
Brigitte Eisenmann ◽  
Holger Engelhardt ◽  
Ute Rößler
Keyword(s):  
Crystal Structures ◽  
Covalent Bonding ◽  
Partial Structure ◽  
Alkali Cations ◽  
Orthorhombic System ◽  
Space Group ◽  
Lattice Constants ◽  
Tetrahedral Voids ◽  
Sodium And Potassium

Abstract The metallic lustrous compounds Na2K3[SnP3], Na2Cs3[SnP3], and Na2K3[SnBi3] were prepared from melts of mixtures of the elements. The isotypic compounds Na2K3[SnP3] and Na2Cs3[SnP3] crystallize in the orthorhombic system, space group Cmca (No 64), Z = 8, with lattice constants a = 1996.1 (4)/2047.9(4) pm, b = 669.5(1)/686.5(2) pm, c = 1494.5(2)/1617.8(3) pm. The structure is characterized by dimeric units [Sn2P6] 10- of edge-sharing [SnP4] tetrahe­dra, which are coordinated by the alkali cations. Na2K3[SnBi3] crystallizes in the orthorhombic system, space group Ibca (No 73), Z = 8, with lattice constants a = 718.2(1) pm , b -1692.6(2) pm, c = 2159.5(2) pm. In the anionic partial structure [SnBi4] tetrahedra are connected via common corners to infinite 1∞[SnBi3]5- Zweier single chains. The sodium and potassium cat­ ions separate the chains from each other. Neglecting the distortions caused by covalent bonding and different radii both structure types can be classified as superstructure defect variants of the Li3Bi structure. Different orderings in the occupation of the tetrahedral voids lead to the variants in the anionic assemblies.

Synthesis and X-ray characterization of Li(1−2x)NixTiO(PO4) (0≤x≤0.50)

2003 ◽  
Vol 18 (4) ◽  
pp. 301-305 ◽  
Author(s):  
B. Manoun ◽  
A. El Jazouli ◽  
P. Gravereau ◽  
J. P. Chaminade
Keyword(s):  
Dilute Solutions ◽  
Final Temperature ◽  
Monoclinic System ◽  
Orthorhombic System ◽  
Space Group ◽  
X Ray

Li(1−2x)NixTiO(PO4) oxyphosphate powders were prepared from dilute solutions of NiCl2⋅6H2O, Li2CO3, (NH4)2HPO4, and TiCl4 in ethanol. The final temperature was 850 °C. Li(1−2x)NixTiO(PO4) oxyphosphates with 0≤x≤0.10 crystallize in the orthorhombic system with space group Pnma, while those with 0.10<x≤0.25 crystallize in the monoclinic system with space group P21/c.

scholarly journals VI. Tabulated data for the examination of the 230 space-groups by homogeneous X-rays

1924 ◽  
Vol 224 (616-625) ◽  
pp. 221-257 ◽  
Keyword(s):  
Crystal Structures ◽  
Chemical Society ◽  
Unit Cell ◽  
X Rays ◽  
Screw Axis ◽  
Monoclinic System ◽  
Space Group ◽  
X Ray ◽  
Space Groups ◽  
Relative Arrangement

The object of the present paper is to express the conclusions of mathematical crystallography in a form which shall be immediately useful to workers using homogeneous X-rays for the analysis of crystal structures. The results are directly applicable to such methods as the Bragg ionisation method, the powder method, the rotating crystal method, etc., and summarise in as compact a form as possible what inferences may be made from the experimental observations, whichever one of the 230 possible space-groups may happen to be under examination. It is only in certain cases that the spacings of crystal planes as determined by the aid of homogeneous X-rays agree with the values of those spacings which would be expected from ordinary crystallographic calculations. In the majority of cases the relative arrangement of the molecules in the unit cell leads to apparent anomalies in the experimental results, the observed spacings of certain planes or sets of planes being sub-multiples of the calculated spacings. The simplest case (fig. 8) of such an apparent anomaly is found in the space-group C 2 2 of the monoclinic system, where the presence of a two-fold screw-axis, because it interleaves halfway the (010) planes by molecules which are exactly like those lying in the (010) planes, except that they have been rotated through 180°, leads to an observed periodicity which is half the periodicity to be inferred from the dimensions of the unit cell, that is, leads to an observed spacing for (010) which is half the calculated. All screw-axes produce similar results, and, in general, a p -fold screw-axis leads to an observed spacing for the plane perpendicular to it which is 1/ p th that to be inferred from the dimensions of the cell. Besides those produced by the screw-axes, other abnormalities arise out of the presence of glide-planes. The simplest case of this is shown by the space-group C s 2 (fig. 4) of the monoclinic system, in which the second molecule is obtained from the first by a reflection in a plane parallel to (010) and half a primitive translation parallel to that plane. If we look along a direction perpendicular to this glide-plane, the projections of the two molecules on the (010) plane are indistinguishable except in position, which is equivalent to saying that, for the purposes of X-ray interference, certain planes perpendicular to this plane of projection are interleaved by an identical molecular distribution. Furthermore, since the translation associated with the glide-plane must always be half a primitive translation parallel to the glide-plane, we know that the interleaving is always a submultiple of the full spacing and the periodicity is again reduced in a corresponding manner. The use of this method for discriminating between the various space-groups of the monoclinic system was described by Sir Wm. Bragg in a lecture to the Chemical Society. In the present paper the method has been extended to the whole of the 230 space-groups possible to crystalline structures. In general, it may be said that if a crystal possesses a certain glide-plane, a certain set of planes lying in the zone whose axis is perpendicular to that glide-plane will have their periodicity reduced by one-half.

Molecular and Crystal Structure of Sildenafil Base

2012 ◽  
Vol 67 (5) ◽  
pp. 491-494 ◽  
Author(s):  
Dmitrijs Stepanovs ◽  
Anatoly Mishnev
Keyword(s):  
Crystal Structure ◽  
Erectile Dysfunction ◽  
Crystal Structures ◽  
Unit Cell ◽  
Sildenafil Citrate ◽  
Unit Cell Parameters ◽  
Monoclinic System ◽  
Space Group ◽  
X Ray ◽  
Cell Parameters

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.

X-ray powder diffraction studies of aniline derivatives

2003 ◽  
Vol 18 (3) ◽  
pp. 266-268
Author(s):  
A. Rafalska-Łasocha ◽  
W. Łasocha
Keyword(s):  
Powder Diffraction ◽  
Room Temperature ◽  
Unit Cell Parameters ◽  
Monoclinic System ◽  
Orthorhombic System ◽  
Space Group ◽  
X Ray ◽  
Cell Parameters ◽  
Aniline Derivatives ◽  
Diffraction Patterns

The X-ray powder diffraction patterns of two liquid aniline derivatives o-chloroaniline, and m-chloroaniline were measured at 250 °K in a low temperature chamber. Both compounds crystallize in the orthorhombic system with the unit cell parameters refined to a=1.8391(3) nm, b=1.0357(2) nm, c=0.6092(1) nm, space group Pmmm(47) and a=0.450 39(9) nm, b=1.9820(4) nm, c=1.2699(4) nm, space group Pcca(54) for o-chloroaniline and m-chloroaniline, respectively. Investigated at room temperature, 2,6-dichloroaniline crystallizes in the monoclinic system, space group P21/c(14), a=1.1329(2) nm, b=0.41093(8) nm, c=1.5445(3) nm, α=γ=90° β=99.96(2)°.

scholarly journals Crystal Structures of Two Macrocyclic Bischalcones Possessing 26-Membered Rings

2015 ◽  
Vol 2015 ◽  
pp. 1-5
Author(s):  
Rina Mondal ◽  
Nayim Sepay ◽  
Debajyoti Ghoshal ◽  
Asok K. Mallik
Keyword(s):  
Hydrogen Bonding ◽  
Single Crystal ◽  
Crystal Structures ◽  
Membered Ring ◽  
X Ray Diffraction ◽  
Monoclinic System ◽  
Triclinic Space Group ◽  
Space Group ◽  
X Ray ◽  
Hydrogen Bonding Interactions

Single crystal X-ray diffraction of two macrocyclic bischalcones, namely, (2E,25E)-11,17,33,37-tetraoxapentacyclo[36.4.0.05,10.018,23.027,32]dotetraconta-1(42),2,5,7,9,18,20,22,25,27,29,31,38,40-tetradecaene-4,24-dione(1) and (2E,24E)-11,16,32,37-tetraoxapentacyclo[36.4.0.05,10.017,22.026,31]dotetraconta-1(42),2,5,7,9,17,19,21,24,26,28,30,38,40-tetradecaene-4,23-dione(2), each containing a 26-membered ring, has been studied. Compound 1 belongs to the monoclinic system, space group C2/c with a = 34.3615(9) Å, b = 12.7995(3) Å, c = 14.6231(3) Å, β = 96.912(2)°,  V = 6,384.6(3) Å3, and Z = 8. Compound 2 is triclinic, space group P-1 with a = 10.066(2) Å, b = 10.670(3) Å, c = 16.590(3) Å, α = 85.95(2), β = 89.244(14), γ = 62.211(13), V = 1572.0(6) Å3, and Z = 2. Intermolecular C–H⋯O hydrogen bonding interactions are present in both compounds.

Sr3GaSb3 und Sr3InP3, zwei neue Zintlphasen mit komplexen Anionen / Sr3GaSb3 and Sr3InP3, Two New Zintl Phases with Complex Anions

1987 ◽  
Vol 42 (10) ◽  
pp. 1268-1272 ◽  
Author(s):  
Gerhard Cordier ◽  
Herbert Schäfer ◽  
Michael Stelter
Keyword(s):  
Zintl Phases ◽  
Monoclinic System ◽  
Orthorhombic System ◽  
Space Group ◽  
Lattice Constants ◽  
Complex Anions

Abstract The new compound Sr3GaSb3 crystallizes in the monoclinic system, space group P21/n (No. 14) with the lattice constants: a = 1176.2(4) pm, b = 1450.9(5) pm, c = 1174.9(4) pm, β = 110.0(1)°. In the structure distorted GaSb4 tetrahedra are connected by common corners, to give strands with groups of four tetrahedra as the repeating unit. The new compound Sr3InP, crystallizes in the orthorhombic system, space group Pnma (No. 62) with the lattice constants: a = 1280.9(5) pm, b = 433.0(2) pm, c =1386.6(5) pm. In the structure distorted InP4 tetrahedra are connected by common corners, to give strands with one tetrahedron as the repeating unit. Both compounds are Zintl phases.

Alkalimetall-Oxosilicate A6[Si3O9] und A6[Si2O7] (A = Rb, Cs): Darstellung und Kristallstruktur/ The Alkaline Metal Oxo-Silicates A6[Si3O9] and A6[Si2O7] (A = Rb, Cs): Preparation and Crystal Structure

2001 ◽  
Vol 56 (4-5) ◽  
pp. 423-430 ◽  
Author(s):  
C. Hoch ◽  
C. Röhr
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Crystal Structures ◽  
Alkali Metals ◽  
Alkaline Metal ◽  
Monoclinic System ◽  
Space Group ◽  
X Ray ◽  
Lattice Constants

Abstract The title compounds were synthesized via reaction of quartz and AO2 (A = Rb, Cs) with the elemental alkali metals. Their crystal structures were determined on the basis of single crystal X-ray data. All compounds crystallize in the monoclinic system with space group P21/c and lattice constants a = 656.0(l)/684.7(3), b = 1329.7(3)/1375.7(4), c = 1647.6(3)/1703.6(8) pm, β = 107.78(3)/108.23(2)°, Z = 4 (A6[Si3O9], A = Rb/Cs) and a = 668.59(8)/711.4(1), b = 911.37(9)/952.1(2), c = 1121.09(9)/1192.7(7) pm, β = 125.52(9)/126.22(3)°, Z = 2(A6[Si2O7], A = Rb/Cs) respectively. The rubidium and cesium compounds are isotypic with the corresponding potassium silicates.

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