The Nitration of Tetrachlorocatechol and 3,4,6-Trichloro-5-methylcatechol. The Formation of 1-Hydroxycyclopent-3-enecarboxylic Acids

1992 ◽  
Vol 45 (4) ◽  
pp. 713 ◽  
Author(s):  
JL Calvert ◽  
JLM Gordon ◽  
MP Hartshorn ◽  
WT Robinson ◽  
GJ Wright
Keyword(s):  
Crystal Structure ◽  
Nitric Acid ◽  
Methyl Ester ◽  
X Ray ◽  
Structure Determinations

Reaction of tetrachlorocatechol (la) with nitric acid (d 1.48) gives the ring-contracted hydroxy dinitro acid (4), which was isolated as its ether solvate. Similar nitration of 3,4,6-trichloro-5-methylcatechol (lb) gives a mixture of stereoisomeric hydroxy dinitro acids (5), from which the methoxy methyl ester (8) can be isolated after methylation of the mixture with diazomethane. X-Ray crystal structure determinations are reported for the etherate of hydroxy dinitro acid (4) and the methoxy methyl ester (8).

The Nitration of 2,3,4-Tribromo-5,6-dimethylphenol and 3,4-Dibromo-2,5,6-trimethylphenol

1985 ◽  
Vol 38 (1) ◽  
pp. 133 ◽  
Author(s):  
MV Chambers ◽  
MP Hartshorn ◽  
WT Robinson ◽  
J Vaughan
Keyword(s):  
Crystal Structure ◽  
Acetic Acid ◽  
Nitric Acid ◽  
X Ray ◽  
Structure Determinations ◽  
Fuming Nitric Acid

The nitrations of 2,3,4-tribromo-5,6-dimethylphenol (9) and 3,4- dibromo-2,5,6-trimethylphenol (10) with fuming nitric acid in acetic acid give 2,5,6-trinitrocyclohex-3-enones in addition to 6-hydroxy-2,5-dinitrocyclohex-3-enones. X-ray crystal structure determinations are reported for the trinitro ketones (21) and (22), and the hydroxy dinitro ketones (23) and (24).

Preparations, X-ray crystal structure determinations, and base strength measurements of substituted tritylamines

2000 ◽  
pp. 85-92 ◽  
Author(s):  
Moisés Canle L. ◽  
William Clegg ◽  
Ibrahim Demirtas ◽  
Mark R. J. Elsegood ◽  
Howard Maskill
Keyword(s):  
Crystal Structure ◽  
X Ray ◽  
Structure Determinations ◽  
Base Strength

Synthesen und Kristallstrukturen von [PPh3Me]NO2 und [PPh3 Me]HCO2H2O / Syntheses and Crystal Structures of [PPh3Me]NO2 and [PPh3Me]HCO2H2O

1988 ◽  
Vol 43 (10) ◽  
pp. 1279-1284 ◽  
Author(s):  
Mervat El Essawi ◽  
H Gosmann ◽  
D Fenske ◽  
F Schmock ◽  
K Dehnicke
Keyword(s):  
Crystal Structure ◽  
Aqueous Solutions ◽  
Ir Spectra ◽  
Bond Angle ◽  
Water Molecules ◽  
Moist Air ◽  
Space Group ◽  
X Ray ◽  
Bond Lengths ◽  
Structure Determinations

Triphenylmethylphosphonium nitrite and formate have been prepared by the reaction of [PPh3Me]I with silver nitrite, and lead formate, respectively, in aqueous solutions. [PPh3Me]NO2 (1) forms pale yellow crystals, and [PPh3Me]HCO2·H2O (2) forms white crystals. Both compounds are soluble in water, ethanol, and dichloromethane. In moist air 2 is hydrated to yield [PPh3Me]HCO2·2H2O (3). The compounds were characterized by their IR spectra, 1 and 2 also by X-ray crystal structure determinations.[PPh3Me]NO2 (1): space group P21/n, Z = 4, 2088 independent observed reflexions, R = 0.062. Lattice dimensions (20 °C): a = 914.7(3), b = 1887.5(9), c = 1080.0(4) pm, β = 110.29(3)°. The compound consists of PPh3Me+ ions and NO2- anions with bond lengths of 114.2(6) pm and a bond angle of 124.1(7)°. [PPh3Me]HCO2·H2O (2): space group P21/n, Z = 4, 2973 independent observed reflexions, R = 0.069. Lattice dimensions (-20 °C): a = 931(2), b = 1558(3), c = 1281(2) pm, β = 105.9(1)°. The compound consists of PPh3Me+ ions and formate anions which form centrosymmetric dimeric units [HCO2·H2O]22- through hydrogen bridges of the water molecules. Bond lengths CO 122.4(4) and 120.9(4) pm. bond angle OCO 129.9(4)°.

Monoolefincobalt(0)-Komplexe / Monoolefincobalt(0) Complexes

1988 ◽  
Vol 43 (10) ◽  
pp. 1256-1262 ◽  
Author(s):  
Hans-Friedrich Klein ◽  
Goetz Lull ◽  
Birgit Rodenhäuser ◽  
Gerhard Cordier ◽  
Helmut Paulus
Keyword(s):  
Crystal Structure ◽  
Carbon Monoxide ◽  
Valence State ◽  
Cobalt Atom ◽  
Spectroscopic Properties ◽  
X Ray ◽  
Mononuclear Cobalt ◽  
Structure Determinations

Mononuclear cobalt(o) complexes containing olefin and trimethylphosphane ligands Co(olefin)(PMe3)3 (olefin = C2H4 (1), C3H6 (2), cyclopentene (3), trans-1,2-diphenylethene (4), tetrafluorobenzo-bicyclo-(2.2.2)-octadiene (5)), are obtained from CoCl2 by reaction with magnesium in the presence of the ligands or by substitution of 3 with olefin. X-ray crystal structure determinations of 4 and 5 show a distorted tetrahedral arrangement of ligands around the cobalt atom. Chemical and spectroscopic properties are consistent with a paramagnetic valence state of the compounds in solution. By reaction with carbon monoxide a dicobalt complex is formed, while azobenzene gives paramagnetic Co(N2Ph2)(PMe3)2.

Crystal-to-Crystal Diastereoselective Transformation of 2,4,6-Triisopropyl-4'-(S)-phenylalaninocarbonylbenzophenone Methyl Ester

1998 ◽  
Vol 54 (6) ◽  
pp. 907-911 ◽  
Author(s):  
H. Hosomi ◽  
Y. Ito ◽  
S. Ohba
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
Methyl Ester ◽  
Absolute Configuration ◽  
Crystal Structure Analysis ◽  
X Ray Diffraction ◽  
Pass Filter ◽  
X Ray ◽  
Ultra High Pressure ◽  
Phenylalanine Methyl Ester

Dissymmetry of the photoproduct was induced by using a chiral substituent, (S)-methylphenylalanine, in the title compound {N-4-(2,4,6-triisopropylbenzoyl)benzoyl]-(S)-phenylalanine methyl ester (I)}. On irradiation with light from a 250 W ultra-high-pressure Hg lamp for 7 h through a long-pass filter, the photoreaction in a crystal was 100% complete without the loss of crystallinity. The crystal structures (I), before, and (II) {N-[4-(7-hydroxy-3,5-diisopropyl-8,8-dimethylbicyclo[4.2.0]octa-1,3,5-trien-7-yl)benzoyl]-(S)-phenylalanine methyl ester}, after photocyclization, have been determined by X-ray diffraction. For comparison, a crystal structure analysis has also been carried out for the photoproduct (III) of the 3′-COOMe derivative after recrystallization {methyl 3-(7-hydroxy-3,5-diisopropyl-8,8-dimethylbicyclo[4.2.0]octa-1,3,5-trien-7-yl)benzoate}. The dihedral angle between the central carbonyl plane and the triisopropylphenyl ring deviates from 90° by 10 (1)° in (I), which makes an imbalance in the intramolecular O(carbonyl)...H(methine) distances of the isopropyl groups at positions 2 and 6. The crystal structure of (II) indicates that the nearer methine H was predominantly abstracted by the carbonyl O atom in the reaction. The absolute configuration around the asymmetric C atom in the cyclobutenol ring of the product is S.

The Nitration of 4,6-Disubstituted 2-Phenylphenols. Some Structural Studies

1985 ◽  
Vol 38 (4) ◽  
pp. 575 ◽  
Author(s):  
MP Hartshorn ◽  
WT Robinson ◽  
J Vaughan ◽  
JM White
Keyword(s):  
Crystal Structure ◽  
Nitrogen Dioxide ◽  
Structural Studies ◽  
X Ray ◽  
Structure Determinations

Nitration of the bromophenols (4a) and (5a) give products of nitro-debromination . Reaction of 6-methyl-4-nitro-2-phenylphenol (5c) with nitrogen dioxide gives 2-hydroxy-2-phenylcyclohex-3-enones (8) and (9), and probably stereoisomers (10), (20), (21) and (22). The mode of ormation of these compounds is discussed. X-ray crystal structure determinations are reported for compounds (8) and (9).

Powder diffraction data of two tricydic diazonia diiodide salts used in silver iodide solid electrolytes

1993 ◽  
Vol 8 (3) ◽  
pp. 175-179
Author(s):  
J. Estienne ◽  
O. Cerclier ◽  
J. J. Rosenberg
Keyword(s):  
Crystal Structure ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Silver Iodide ◽  
Solid Electrolytes ◽  
Rietveld Method ◽  
Powder Diffraction Data ◽  
Organic Salts ◽  
X Ray ◽  
Structure Determinations

Indexed X-ray powder diffraction data are reported for two organic salts with carbon rings having two quaternary nitrogens: diazonia-6,9 dispiro [5.2.5.2] hexadecane and diazonia-6,9 dispiro [5.2.5.3] heptadecane diiodides. For these compounds, which give solid electrolytes when associated with AgI, powder diffraction diagrams calculated by the Rietveld method from single crystal structure determinations are presented and are compared to the experimental diffraction data.

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