Chemistry and crystal structures of 1,3-Bis(4'-bromophenyl)propane- 1,2,3-trione, 3,5-Diphenyl- 1,2-dithiolylium-4-olate and 4-Hydroxy-3,5-diphenyl-1,2-dithiolium perchlorate

1978 ◽  
Vol 31 (2) ◽  
pp. 297 ◽  
Author(s):  
JR Cannon ◽  
KT Potts ◽  
CL Raston ◽  
AF Sierakowski ◽  
AH White
Keyword(s):  
Crystal Structures ◽  
Heterocyclic System ◽  
Cycloaddition Reaction ◽  
Heterocyclic Ring ◽  
Dipolar Cycloaddition ◽  
Carbonyl Groups ◽  
X Ray Diffraction ◽  
Full Matrix ◽  
X Ray ◽  
Phenyl Rings

In connection with studies on possible mesoionic systems, syntheses of 1,3-bis(4'-bromophenyl)-propane-1,2,3-trione (5), 3,5-diphenyl-1,2-dithiolylium-4-olate (9) and 4-hydroxy-3,5-diphenyl-1,2-dithiolium perchlorate (10) have been reexamined. ��� The crystal structures of (5), (9) and (10) have been determined by X-ray diffraction from diffractometer data at 295 K and were refined by full-matrix least squares to residuals of 0.050 (1118 'observed' reflections), 0.072 (2388) and 0.087 (2000), respectively. Crystals of (5) are monoclinic, C2/c, a 18.535(4), b 7.734(2), c 12.184(3) Ǻ, β 126.60(3)°, Z 4. Crystals of (9) are orthorhombic, Pmcn, a 26.047(6), b 7.170(2), c 6.431(2) Ǻ, Z 4. Crystals of (10) are monoclinic, P21/a, a 18.601(7), b 10.636(4), c 8.152(2) Ǻ, β 102.60(3)°, Z 4. ��� In (5) π-character is localized in the phenyl rings and carbonyl groups [<C=O> 1.22(1) Ǻ] and the substance is best represented as a normal vicinal triketone. In (9) and (10) S-S bonds are present and (9) is correctly regarded as a heterocyclic system. The geometry of the heterocyclic ring in (10) agrees well with that previously found for the 1,2-dithiolium cation; <C-O> is 1.35(1) Ǻ. In (9) the heterocyclic C-C distances [1.442(2)Ǻ] are longer than in (10); this indicates diminished aromaticity on deprotonation. The C-C-C angle [111.2(2)°] in (9) is also smaller than that [118.3(8)°] in (10) and <C-O> in (9) is 1.250(3) Ǻ. ��� The behaviour of 1,3-diphenylpropane-1,2,3-trione (4) and (9) with acetylenic dipolarophiles has been studied but no evidence has been obtained that either substance undergoes a 1,3-dipolar cycloaddition reaction.

A REFINEMENT OF THE CRYSTAL STRUCTURES OF (NH4)2TeBr6 AND Cs2TeBr6

1966 ◽  
Vol 44 (8) ◽  
pp. 939-943 ◽  
Author(s):  
A. K. Das ◽  
I. D. Brown
Keyword(s):  
Least Squares ◽  
Crystal Structures ◽  
Diffraction Data ◽  
Bromine Atom ◽  
Three Dimensional ◽  
X Ray Diffraction ◽  
Full Matrix ◽  
X Ray ◽  
Anisotropic Temperature ◽  
Temperature Factors

(NH4)2TeBr6 and Cs2TeBr6 crystals have the cubic K2PtCl6 structure with space group: [Formula: see text] with a0 = 10.728 ± 0.003 Å and 10.918 ± 0.002 Å respectively. The positional coordinate of the bromine atom, and the anisotropic temperature factors of all atoms in the unit cell, have been refined for both crystals by a full matrix least-squares analysis of the three dimensional X-ray diffraction data (R = 0.08). The Te—Br distance, corrected for probable thermal motions of atoms forming the bond, is 2.70 ± 0.01 Å in both crystals.

The Flavonoids of Combretum quadrangulare: Crystal structures of the Polymorphic Forms of 5-Hydroxy-2-(4'-hydroxy-3',5'-dimethoxyphenyl)-3,7-dimethoxy-4H-1-benzopyran-4-one

1985 ◽  
Vol 38 (8) ◽  
pp. 1177 ◽  
Author(s):  
IR Castleden ◽  
SR Hall ◽  
S Nimgirawath ◽  
S Thadaniti ◽  
AH White
Keyword(s):  
Least Squares ◽  
Crystal Structures ◽  
X Ray Diffraction ◽  
Full Matrix ◽  
X Ray ◽  
Β Phase ◽  
Α Phase ◽  
Polymorphic Forms

The following substituted 2-phenyl-4H-1-benzopyran-4-ones have been isolated from the dried flowers of Combretum quadrangulare Kurz ( Combretaceae ): 5-hydroxy-3,3′,4′,5′,7-pentamethoxy ( combretol ) (1), 3′,5-dihydroxy-3,4′,7-trimethoxy ( ayanin ) (2) and 4′,5-dihydroxy- 3,3′,5′,7-tetramethoxy (3). The last substance (3) was obtained as a mixture of two polymorphic forms (α and β) each of which was characterized by X-ray diffraction. Diffractometer data at 295 K were refined by full matrix least squares to residuals of 0.043 (1181 'observed' reflections) for the α-phase and 0.044 (1421) for the β phase of (3). Crystals of the α-phase of (3) are triclinic, Pī, a 12.663(6), b 9.592(4), c 7.444(4) Ǻ, α 102.48(3), β 101.39(4), γ 91.72(4)°,Z 2. Crystals of the β-phase of (3) are monoclinic P21/n, a 17.139(8), b 12.728(6), c 7.845(7) Ǻ, β 95.07(6)°, Z 4. An unambiguous synthesis of (3) was also achieved.

A Convenient Synthesis of Fused Tetrahydroazocines from Acenaphthylene-1,2-dione, Proline, and Acetylenic Esters

Synlett ◽  
2017 ◽  
Vol 29 (05) ◽  
pp. 635-639 ◽  
Author(s):  
Issa Yavari ◽  
Leila Baoosi ◽  
Mohammad Halvagar
Keyword(s):  
Cycloaddition Reaction ◽  
Azomethine Ylides ◽  
Dipolar Cycloaddition ◽  
X Ray Diffraction ◽  
Acetylenic Esters ◽  
X Ray ◽  
Convenient Synthesis ◽  
Boat Form ◽  
Twist Boat

A synthesis of dialkyl (12E,14E)-7-oxo-10,11-dihydro-7H,9H-azocino[2,1-a]benzo[de]isoquinoline-13,14-dicarboxylates through a 1,3-dipolar cycloaddition reaction of azomethine ylides, generated in situ from proline and acenaphthylene-1,2-dione, with dialkyl acetylenedicarboxylates is described. According to the X-ray diffraction data, the tetrahydroazocine ring has a rigid twist-boat form with approximate local C2 symmetry.

scholarly journals Crystal structure of Tetraaqua(ethylenediamine)nickel(II) sulfate dihydrate and of Tetraaqua(2,2'-bipyridyl)nickel(II) sulfate dihydrate

1984 ◽  
Vol 37 (5) ◽  
pp. 921 ◽  
Author(s):  
PC Healy ◽  
JM Patrick ◽  
AH White
Keyword(s):  
Crystal Structure ◽  
Water Molecule ◽  
Single Crystal ◽  
Least Squares ◽  
Crystal Structures ◽  
X Ray Diffraction ◽  
Full Matrix ◽  
X Ray ◽  
Oxygen Atoms

The crystal structures of the title compounds, [Ni(OH2)4(en)] [SO4].2H2O, (1), and [Ni(OH2)4(bpy)]- [SO4].2H2O, (2), have been determined by single-crystal X-ray diffraction methods at 295 K, being refined by full matrix least-squares methods to residuals of 0.028,0.031 for 1852, 4323 independent 'observed' reflections respectively. Crystals of (1) are monoclinic, C2/c, a 9.459(4), b 12.192(7), c 12.294(3) �, β 119.84(4)�, Z 4. In the cation, Ni-N is 2.061(2) �; Ni-O (trans to O, N respectively) are 2.106(2), 2.063(2) �. Instead of being enlarged above 90� as predicted from repulsion theory, the angle between the pair of oxygen atoms trans to nitrogen is diminished, being 87 14(7)�. Crystals of (2) are triclinic, P1, a 11.476(5), b 9.351(5), c 7.793(4) �, α 77.63(4), β 83.52(3), γ87.40(4)�, Z 2. In the cation, Ni-N are both 2.063(2) �. Ni-O (trans to N, O respectively) are 2.060(2), 2.O42(2); 2.O80(2), 2�. The short Ni-O distance [2.042(2)�] is associated with the coordination of a trigonal water molecule.

The Crystal-Structures of (±)-(E)-2-(1-Amino-Ethylidene)-4,4,6-Trimethylcyclohexane-1,3-Dione [(±)-Aminoangustione] and (E)-2-(1-Aminoethylidene)-4,6,6-Trimethylcyclohex-4-Ene-1,3-Dione (Aminodehydroangustione)

1986 ◽  
Vol 39 (6) ◽  
pp. 923 ◽  
Author(s):  
JR Cannon ◽  
VA Patrick ◽  
AH White
Keyword(s):  
Least Squares ◽  
Crystal Structures ◽  
X Ray Diffraction ◽  
Full Matrix ◽  
X Ray

The crystal structures of (�)-(E)-2-(1-aminoethylidene)-4,4,6- trimethylcyclohexane-1,3-dione [(�)- aminoangustione ] (8) and (E)-2-(1- aminoethylidene )-4,6,6-trimethylcyclohex-4-ene-1,3-dione ( aminodehydroangustione ) (9) have been determined by X-ray diffraction. Diffractometer data at 295 K were refined by full-matrix least-squares to residuals of 0.057 (712 'observed' reflections) for (8) and 0.061 (571) for (9). Crystals of (8) are tetragonal I 41/a, a 21.68(1), c 9.426(6)Ǻ, Z 16; crystals of (9) are orthorhombic Pmab , a 7.077(2), b 11.421(6), c 13.283(4)Ǻ, Z 4.

Crystal structures of trans-Dichloro- and Dibromo-bis(2,6-dimethylpyridine)copper(II)

1977 ◽  
Vol 30 (9) ◽  
pp. 1947 ◽  
Author(s):  
JA Campbell ◽  
CL Raston ◽  
JN Varghese ◽  
AH White
Keyword(s):  
Least Squares ◽  
Crystal Structures ◽  
X Ray Diffraction ◽  
Compound A ◽  
Full Matrix ◽  
X Ray ◽  
Square Planar

The crystal structures of the title compounds have been determined at 295(1) K by X-ray diffraction and refined by full-matrix least squares to residuals of 0.045 and 0.067 for 1224 and 1955 ?observed? reflections respectively. The compounds are isomorphous (triclinic, Pī, Z 1). Dichloro compound: a 8.068(2), b 8.024(2), c 7.646(2) Ǻ, α 93.84(2), β 113.44(2), γ 117.11(2)�. Dibromo compound: a 7.999(2), b 7.921(2), c 7.849(2) Ǻ, α 94.37(2), β 112.85(2), γ 115.99(2)�. The copper atoms are square-planar coordinated with two halide and two base ligands coordinated necessarily trans by virtue of the siting of the molecule on a centre of symmetry. Cu-X, Cu-N are 2.264(2), 2.011(3) (dichloro); 2.425(1), 1.997(4) Ǻ (dibromo). The plane of the lutidine is almost normal to the CuN2X2 plane.

scholarly journals Synthesis of 1-(2-Fluorophenyl)pyrazoles by 1,3-Dipolar Cycloaddition of the Corresponding Sydnones

Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3693
Author(s):  
Denisa Dumitrescu ◽  
Sergiu Shova ◽  
Constantin Draghici ◽  
Marcel Mirel Popa ◽  
Florea Dumitrascu
Keyword(s):  
Crystal Structure ◽  
Nmr Spectroscopy ◽  
Cycloaddition Reaction ◽  
Halogen Bonding ◽  
Dipolar Cycloaddition ◽  
Dimethyl Acetylenedicarboxylate ◽  
Reaction Intermediates ◽  
X Ray Diffraction ◽  
X Ray ◽  
Important Interaction

3-Arylsydnones bearing fluorine and bromine atoms on the benzene ring were synthesized from N-nitroso-2-fluorophenylglycines and characterized by NMR spectroscopy. These were employed further in synthesis of the corresponding 1-(2-fluorophenyl)pyrazoles by 1,3-dipolar cycloaddition reaction with dimethyl acetylenedicarboxylate (DMAD) as activated dipolarophile. The sydnones as reaction intermediates were characterized by single crystal X-ray diffraction analysis showing interesting features such as halogen bonding as an important interaction in modeling the crystal structure.

Synthesis and X-ray diffraction data of (4R)-methyl-3-(1-(4-chlorophenyl)-1H-1,2,3-triazole-4-carbonyl)thiazolidin-4-carboxylate, C14H13ClN4O3S

2019 ◽  
Vol 35 (1) ◽  
pp. 41-44
Author(s):  
Fausto M. Güiza ◽  
Arnold R. Romero Bohórquez ◽  
J. A. Henao ◽  
H. A. Camargo
Keyword(s):  
Mass Spectrometry ◽  
Infrared Spectroscopy ◽  
Cycloaddition Reaction ◽  
Unit Cell ◽  
Dipolar Cycloaddition ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
Orthorhombic System ◽  
X Ray ◽  
Cell Parameters

The new compound (4R)-methyl-3-(1-(4-chlorophenyl)-1H-1,2,3-triazole-4-carbonyl)thiazolidin-4-carboxylate was synthesized by the 1,3-dipolar cycloaddition reaction between (4R)-methyl-3-propionyl-thiazolidin-4-carboxylate (1) and 4-chlorophenylazide using the click chemistry approach. Molecular characterization was carried out by infrared spectroscopy and mass spectrometry. The X-ray powder diffraction study determined that the title compound crystallized in an orthorhombic system with unit-cell parameters a = 20.876 (2) Å, b = 12.111 (1) Å, and c = 6.288 (9) Å. The volume of the unit cell is V = 1589.7 (2) Å3. All measured diffraction maxima were indexed and are consistent with the P2221 space group (No. 17). No detectable impurities were observed.

Stereochemistry of Substituted Isomeric 3-Oxa-7-aza-bicyclo[3.3.1]nonan-9-ones

1987 ◽  
Vol 42 (2) ◽  
pp. 221-228 ◽  
Author(s):  
Horst Küppers ◽  
Karl-F. Hesse ◽  
Ulrike Ashauer-Holzgrabe ◽  
Rolf Haller ◽  
Roland Boese
Keyword(s):  
Nmr Spectroscopy ◽  
Nitrogen Atom ◽  
Crystal Structures ◽  
Chair Conformation ◽  
Heterocyclic Ring ◽  
Boat Conformation ◽  
Bulky Substituent ◽  
X Ray Diffraction ◽  
Triclinic Space Group ◽  
X Ray

Abstract Two isomers of 7-methyl-9-oxo-2,4-diphenyl-3-oxa-7-aza-bicyclo[3.3.1]nonan-1,5-ethyl dicarboxylate (1a and 1b) were obtained by condensation of 2,6-diphenyl-1-oxa-4-oxo-cyclohexan-3,5-ethyl dicarboxylate with methylamine and formaldehyde. Their crystal structures were determined by X-ray diffraction. They crystallize in the triclinic space group P1̄ with (for 1a) a = 12.907(5), b = 11.223(4), c = 8.993(4) Å, α = 105.82(4), β = 100.14(5), γ = 97.35(4)°, and (for 1b) a = 16.400(7), b = 13.062(4), c = 11.336(2) Å, α = 94.19(3), β = 94.74(3), γ = 102.56(4)°. This investigation has shown that isomer 1a has the boat-chair conformation, and isomer 1b has the chair-chair conformation. The formation of la causes a configurational change of the phenyl substituents. The two species are characterized by NMR spectroscopy. - Another comparable bicyclononanone with a bulky substituent at the nitrogen atom has been synthesized and was investigated spectroscopically. This compound should have chair-boat conformation (with the boat conformation in the N-heterocyclic ring) whereas 1a has the boat conformation in the O-heterocyclic ring.

Crystal structures of o-phenylenediarsine oxychloride (a redetermination) and o-phenylenediarsine oxybromide

1975 ◽  
Vol 28 (1) ◽  
pp. 15 ◽  
Author(s):  
JC Dewan ◽  
K Henrick ◽  
AH White ◽  
SB Wild
Keyword(s):  
Least Squares ◽  
Crystal Structures ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Full Matrix ◽  
Space Group ◽  
X Ray ◽  
Limits Of Error

The crystal structures of the title compounds have been established by X-ray diffraction at 295 K, being refined by full-matrix least-squares to residuals of 0.054 (0.051) respectively 2715 (469) reflections with I > σ(I)]. Crystals are monoclinic, space group C2/c, the compounds being isomorphous. Oxychloride: a = 14.534(4), b = 8.337(2), c = 7.653(1)Ǻ, β = 106.48(1)�. Oxybromide: a = 14.884(4), b = 8.360(2), c = 7.726(1)Ǻ, β = 105.30(1)�, Z = 4. With the exception-of the arsenic- halogen distance, the geometries of the two molecules are identical within the limits of error: for the oxychloride As-O-As, 121.8(3); Cl- As-O,98.03(6); Cl-As-C, 97.2(2); O-As-C, 92. 9(2)� ; As-O, 1.787(3); As-C, 1.941(5) Ǻ. As-Cl is 2.222(2) and As-Br 2.381(2) Ǻ.

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