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).

Photochemical Nitration by Tetranitromethane. XXXII. Adduct Formation in the Photochemical Reaction of Phenanthrene and Tetranitromethane

1996 ◽  
Vol 49 (4) ◽  
pp. 469
Author(s):  
CP Butts ◽  
L Eberson ◽  
KL Fulton ◽  
MP Hartshorn ◽  
WT Robinson
Keyword(s):  
Crystal Structure ◽  
Charge Transfer ◽  
Nitrogen Dioxide ◽  
Photochemical Reaction ◽  
Charge Transfer Complex ◽  
Major Product ◽  
Adduct Formation ◽  
X Ray ◽  
Structure Determinations ◽  
Ion Recombination

Photolysis of the phenanthrene/tetranitromethane charge-transfer complex yields the triad of phenanthrene radical cation, nitrogen dioxide, and trinitromethanide ion. Recombination of this triad in dichloromethane at 20° gives 9-nitrophenanthrene (1), trans-10-trinitromethyl-9,10-dihydrophenanthren-9-yl nitrate (2a), trans-9-nitro-10-trinitromethyl-9,10-dihydrophenanthrene (2b), and trans-10-trinitromethyl-9,10-dihydrophenanthren-9-ol (2c). Adduct formation is partially suppressed when trifluoroacetic acid (0.7 M) is added to the dichloromethane solvent at 20°, the major product identified being 9-nitrophenanthrene (1). At -20° in dichloromethane, or in acetonitrile at 20°, 10'-nitro-9,9',10,10'-tetrahydro-9,9'-biphenanthren-10-yl nitrate (3) is formed, apparently by reaction of nitrogen dioxide with phenanthrene. X-Ray crystal structure determinations are reported for adducts (2a,b).

Reactions of 1,4-Dimethyl-4-nitro-cyclohexa-2,5-dien-1-yl Acetates With Nitrogen Dioxide; the Formation of Polynitro Cyclohexenyl Esters

1991 ◽  
Vol 44 (1) ◽  
pp. 43 ◽  
Author(s):  
AD Abell ◽  
MP Hartshorn ◽  
ME Maclennan ◽  
WT Robinson ◽  
GJ Wright
Keyword(s):  
Crystal Structure ◽  
Acetic Anhydride ◽  
Nitrogen Dioxide ◽  
Aromatic Compounds ◽  
X Ray ◽  
Nitrate Esters ◽  
Structure Determinations ◽  
Nitro Aromatic

Reactions of the epimeric 4-nitrocyclohexa-2,5-dienyl acetates (10) and (11) with nitrogen dioxide in acetic anhydride give closely similar mixtures of the nitro aromatic compounds (12)-(15), three polynitro nitrate esters (16)-(18), and two polynitro acetates (19) and (20). X-Ray crystal structure determinations are reported for compounds (16)-(18).

The Mechanism and Stereochemistry of Chlorination of Some 2,4-Dichloro-6-methylphenols; X-Ray Crystal Structures of Some Polyhalo Ketones

1994 ◽  
Vol 47 (6) ◽  
pp. 1071 ◽  
Author(s):  
JLM Gordon ◽  
MP Hartshorn ◽  
RJ Martyn ◽  
WT Robinson ◽  
GJ Wright
Keyword(s):  
Crystal Structure ◽  
Crystal Structures ◽  
Structural Studies ◽  
X Ray ◽  
Structure Determinations

The additions of chlorine to the 2,4,6-trichloro-5,6-dimethyl- (7a) and 2,4,6-trichloro-6-methyl- (7b) cyclohexa-2,4-dienones to give pentachlorocyclohexenones (8)-(11) are described. The stereochemistry of some of these additions has been determined from structural studies of the chlorination products of the 2,4-dibromophenols (12). X-Ray crystal structure determinations are reported for compounds (11b), (18), (20) and (23).

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

Comparative Structural Studies on Three-Coordinate Copper(I) Halide Complexes With Tertiary Phosphines. Crystal Structures of [(PPh2Mes)CuX]2 and [(PPhMes2)CuX]2 (Mes = Mesityl X = Cl, Br, I)

1992 ◽  
Vol 45 (7) ◽  
pp. 1155 ◽  
Author(s):  
GA Bowmaker ◽  
D Camp ◽  
RD Hart ◽  
PC Healy ◽  
BW Skelton ◽  
...  
Keyword(s):  
Single Crystal ◽  
Crystal Structures ◽  
Copper Atom ◽  
Structural Studies ◽  
Coordination Environment ◽  
X Ray ◽  
Tertiary Phosphines ◽  
Structure Determinations ◽  
Halide Complexes ◽  
The Subject

The 1 : 1 complexes of the substituted triphenylphosphine ligands mesityldiphenylphosphine and dimesitylphenylphosphine with copper(1) chloride, bromide and iodide have been the subject of single-crystal X-ray structure determinations at 295 K. All six complexes crystallize as air-stable dimeric molecules, [(PPh2Mes)CuX]2 and [ (PPhMes2)CUX]2 with each copper atom in a distorted trigonal PCuX2. coordination environment. Crystals of [(PPh2Mes)CuCl]2 (1) are monoclinic, P21/n, a 9.961(3), b 18.687(6), c 11.009(7) Ǻ, β 114.63(4)°; R was 0.049 for 2450 'observed' reflections. [(PPh2Mes)CuBrI2 (2) is monoclinic, P21/n, a 9.939(2), b 18.832(6), c 11.238(6) Ǻ, β 115.36(3)°; R was 0.046 for 1803 'observed' reflections. [(PPh2Mes)CuI]2.4/3 C6H6 (3) is rhornbohedral, R3, a 36.877(8), c 9.047(5) A; R was 0.039 for 2537 'observed' reflections. Crystals of [(PPhMes2)CuCl]2.2MeCN (4) are triclinic, Pi, a 15.783(7), b 9.570(4), c 8.914(4) Ǻ, α 72.43(3), β 76.37(3), γ 74.03(3)°; R was 0.045 for 3341 'observed' reflections. [(PPhMes2)CuBr]2.3C6H6 (5) is monoclinic, C2/c, a 9.694(6), b 30.15(2), c 20.66(2) Ǻ, β 98.00(7)°; R was 0.047 for 2117 'observed' reflections. [(PPhMes2)CuI]2.2MeCN (6) is orthorhombic, PP1nb, a 11.694(8), b 14.77(1), c 29.76(3) Ǻ; R was 0.049 for 3447 'observed' reflections. Cu-P bond lengths are: 2.196(2) A (1); 2.198(3) Ǻ (2); 2.222(5) and 2.226(5) Ǻ (3); 2.202(1) Ǻ (4); 2.197(3) A (5); 2.201(4) and 2.264(5) Ǻ (6). The geometries of the LCuX2 and CuX2Cu units are compared with data reported for other monomeric and dimeric compounds for both phosphorus- and nitrogen-based ligands L.

Structural Studies on Phenylalanine Hydroxylase and Implications Toward Understanding and Treating Phenylketonuria

PEDIATRICS ◽  
2003 ◽  
Vol 112 (Supplement_4) ◽  
pp. 1557-1565
Author(s):  
Heidi Erlandsen ◽  
Marianne G. Patch ◽  
Alejandra Gamez ◽  
Mary Straub ◽  
Raymond C. Stevens
Keyword(s):  
Molecular Basis ◽  
Phenylalanine Hydroxylase ◽  
Structural Information ◽  
Missense Mutations ◽  
Structural Studies ◽  
Gene Encoding ◽  
X Ray ◽  
3 Dimensional ◽  
Substrate Analogs ◽  
Structure Determinations

Mutations in the gene encoding for phenylalanine hydroxylase (PAH) result in phenylketonuria (PKU) or hyperphenylalaninemia (HPA). Several 3-dimensional structures of truncated forms of PAH have been determined in our laboratory and by others, using x-ray crystallographic techniques. These structures have allowed for a detailed mapping of the >250 missense mutations known to cause PKU or HPA found throughout the 3 domains of PAH. This structural information has helped formulate rules that might aid in predicting the likely effects of unclassified or newly discovered PAH mutations. Also, with the aid of recent crystal structure determinations of co-factor and substrate analogs bound at the PAH active site, the recently discovered tetrahydrobiopterin-responsive PKU/HPA genotypes can be mapped onto the PAH structure, providing a molecular basis for this tetrahydrobiopterin response.

Study of thermal properties of Ga0.5In1.5Se3 by differential scanning calorimetry

2021 ◽  
pp. 2150407
Author(s):  
S. I. Ibrahimova
Keyword(s):  
Crystal Structure ◽  
Differential Scanning Calorimetry ◽  
Thermal Properties ◽  
Thermal Effects ◽  
Room Temperature ◽  
Structural Studies ◽  
X Ray Diffraction ◽  
Hexagonal Symmetry ◽  
Scanning Calorimetry ◽  
X Ray

The crystal structure and thermal properties of the [Formula: see text] compound have been investigated. Structural studies were performed by X-ray diffraction at room temperature. The crystal structure of this compound was found to correspond to the hexagonal symmetry of the space group P61. Thermal properties were studied using a differential scanning calorimetry (DSC). It was found in the temperature range [Formula: see text] that thermal effects occur at temperatures [Formula: see text] and [Formula: see text]. The thermodynamic parameters of these effects are calculated.

Structural studies and antileishmanial activity of 2-acetylpyridine and 2-benzoylpyridine nitroimidazole-derived hydrazones

2019 ◽  
Vol 75 (3) ◽  
pp. 320-328
Author(s):  
Ana P. A. Oliveira ◽  
Isabella P. Ferreira ◽  
Angel A. Recio Despaigne ◽  
Jeferson G. da Silva ◽  
Ana Carolina S. Vieira ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Nitro Group ◽  
Antileishmanial Activity ◽  
Structural Studies ◽  
Antiprotozoal Activity ◽  
Leishmania Chagasi ◽  
Macrophage Cells ◽  
Structure Determinations ◽  
Determining Factor

Three imidazole hydrazone compounds, namely 2-(4-nitro-1H-imidazol-1-yl)-N′-[1-(pyridin-2-yl)ethylidene]acetohydrazide, C12H12N6O3, (1), 2-(2-nitro-1H-imidazol-1-yl)-N′-[1-(pyridin-2-yl)ethylidene]acetohydrazide, C12H12N6O3, (2), and 2-(2-nitro-1H-imidazol-1-yl)-N′-[(phenyl)(pyridin-2-yl)methylidene]acetohydrazide, C17H14N6O3, (3), were obtained and fully characterized, including their crystal structure determinations. While all the compounds proved not to be cytotoxic to J774.A1 macrophage cells, (1) and (3) exhibited activity against Leishmania chagasi, whereas (2) was revealed to be inactive. Since both (1) and (3) exhibited antileishmanial effects, while (2) was devoid of activity, the presence of the acetyl or benzoyl groups was possibly not a determining factor in the observed antiprotozoal activity. In contrast, since (1) and (3) are 4-nitroimidazole derivatives and (2) is a 2-nitroimidazole-derived compound, the presence of the 4-nitro group probably favours antileishmanial activity over the 2-nitro group. The results suggested that further investigations on compounds (1) and (3) as bioreducible antileishmanial prodrug candidates are called for.

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