The Mechanism and Stereochemistry of Chlorination of 2,4-Dichloro-3,,5,6-trimethylphenol and 2,4-Dichloro-3,6-dimethylphenol

1994 ◽  
Vol 47 (2) ◽  
pp. 279 ◽  
Author(s):  
JLM Gordon ◽  
MP Hartshorn ◽  
RJ Martyn ◽  
WT Robinson ◽  
GJ Wright
Keyword(s):  
Crystal Structures ◽  
Similar Reaction ◽  
Electrophilic Attack ◽  
X Ray

Electrophilic attack of chlorine on 2,4,6-trichloro-3,5,6-trimethylcyclohexa-2,4-dienone (2a) gives the trans-pentachloro ketones (3a) and (4a), while similar reaction of 2,4,6-trichloro-3,6-dimethylcyclohexa-2,4-dienone (2b) gives the trans- pentachloro ketones (3b) and (4b), resulting from 2,5- and 4,5-addition of chlorine. The probable stereochemistry of chlorine addition in ketones (3b) and (4b) is determined by chlorination of 2,4-dibromo-3,6-dimethylphenol (6). X-Ray crystal structures are reported for compounds (3a,b), (7) and (8).

Combination of Pyridinium and Isoquinolinium Ylides with Phenylisocyanate and Isothiocyanates: Synthesis, Characterisation, and X-Ray Crystal Structures of Mesoionic Monosubstituted 3-Oxo-Propanamides or Thioamides

2015 ◽  
Vol 68 (10) ◽  
pp. 1577
Author(s):  
Mohammad Seifi ◽  
S. Yousef Ebrahimipour ◽  
Jim Simpson ◽  
Michal Dusek ◽  
Vaclav Eigner ◽  
...  
Keyword(s):  
Single Crystal ◽  
Crystal Structures ◽  
Similar Reaction ◽  
X Ray ◽  
Pyridinium Ylides

Pyridinium ylides derived from 2-bromoacetophenone or methyl bromoacetate have been reacted with phenylisocyanate, phenyl- or methylisothiocyanate to afford mesoionic monosubstituted 3-oxo-propanamides or thioamides, via self-protonation of the intermediate N-anion. A similar reaction under the same conditions of isoquinolinium ylides with phenylisocyanate or phenyisothiocyante also produced the corresponding mesoionic compounds. In order to establish the exact structure of the mesoionic compounds, single crystal X-ray structures were obtained for three of the pyridinium ylides.

Reactions of 3,4,5-Trimethylbiphenyl and 2,3,4-Trimethylbiphenyl With Nitrogen Dioxide

1990 ◽  
Vol 43 (9) ◽  
pp. 1519 ◽  
Author(s):  
MP Hartshorn ◽  
MC Judd ◽  
RJ Martyn ◽  
WT Robinson ◽  
GJ Wright ◽  
...  
Keyword(s):  
Nitrogen Dioxide ◽  
Crystal Structures ◽  
Nitroaromatic Compounds ◽  
Similar Reaction ◽  
X Ray ◽  
Nitrate Esters ◽  
Elimination Mechanism

Reaction of 3,4,5-trimethylbiphenyl (1) with nitrogen dioxide gives four mononitro compounds (3)-(6) and three dinitro compounds (7)-(9). Similar reaction of 2,3,4-trimethylbiphenyl (2) gives three nitroaromatic compounds (11)-(13), three nitrate esters (14)-(16), and two nitro dienones (17) and (18). Dinitro dienone (17) rearranges in solution to give the corresponding hydroxy nitro dienone (19). The differences between the two sets of products are discussed, and an addition-elimination mechanism is proposed for the mode of formation of the nitro dienones (17) and (18). X-Ray crystal structures are reported for compounds (4) and (19).

Distibylation of Acetylenes with Ph2Sb–SbPh2: Synthesis, Crystal Structures and Phosphorescence Properties of Bis(diphenylstibyl)ethenes

2014 ◽  
Vol 69 (11-12) ◽  
pp. 1181-1187
Author(s):  
Joji Ohshita ◽  
Toshiyuki Tsuchida ◽  
Kazuya Murakami ◽  
Yousuke Ooyama ◽  
Takayuki Nakanishi ◽  
...  
Keyword(s):  
Optical Properties ◽  
Solid State ◽  
Low Temperature ◽  
Crystal Structures ◽  
Uv Absorption ◽  
Similar Reaction ◽  
Photoluminescence Spectra ◽  
X Ray Diffraction ◽  
X Ray

Abstract Treatment of tetraphenyldistibine (1) with terminal arylacetylenes, XC6H5C≡CH (2a-c, X=H, F, OMe), gave the corresponding anti-addition products (E)-aryl-1,2-bis(diphenylstibyl)ethenes 3a-c in 11 - 17% yields. A similar reaction of 1 with 1,4-diphenylbutadiyne provided (E)-1,4-diphenyl- 1,2-bis(diphenylstibyl)but-1-en-3-yne (3d) in 28% yield. X-Ray diffraction studies on crystals of 3a, 3b and 3d revealed a congested configuration around the ethylene core. The optical properties of the adducts 3a-d were examined by measuring UV absorption and photoluminescence spectra. Interestingly, 3d showed phosphorescence in the solid state, which was enhanced at low temperature.

scholarly journals Synthesis and crystal structures of two new tin bis(carboranylamidinate) complexes

2017 ◽  
Vol 73 (10) ◽  
pp. 1443-1448 ◽  
Author(s):  
Nicole Harmgarth ◽  
Phil Liebing ◽  
Philipp Hillebrand ◽  
Sabine Busse ◽  
Frank T. Edelmann
Keyword(s):  
Single Crystal ◽  
Crystal Structures ◽  
Structure Analysis ◽  
Lone Pair ◽  
Main Reaction ◽  
Similar Reaction ◽  
Main Reaction Product ◽  
X Ray ◽  
Trigonal Bipyramidal Coordination ◽  
Trigonal Bipyramidal

Reaction of 2 equiv. of the lithium carboranylamidinate Li[o-(C2H10B10)C(NCy)(NHCy)] with SnCl2in THF afforded the stannylene compound bis(N,N′-dicyclohexylamidinatocarboranate)tin(II), SnII[o-(C2H10B10)C(NCy)(NHCy)]2(1). A similar reaction of SnCl4with 2 equiv. of Li[o-(C2H10B10)C(NiPr)(NHiPr)] unexpectedly afforded the known solvated pentachloridostannate(IV) salt [Li(THF)4][SnCl5(THF)] as the main reaction product. Small amounts of the new chlorido-tin(IV) bis(carboranylamidinate) bis(N,N′-diisopropylamidinatocarboranate)chloridotin(IV), SnIVCl[o-(C2H10B10)C(NiPr)(NHiPr)][o-(C2H10B10)C(NiPr)2] (2), were isolated as a by-product. Single-crystal X-ray structure analysis revealed aκC,κN-chelating coordination of the carboranylamidinate ligands in both1and2. The Sn atom in1adopts a pseudo-trigonal–bipyramidal coordination under participation of a stereoactive lone pair. In2, a trigonal–bipyramidal coordination of Sn is completed by a chlorido ligand.

reactions of 2-t-Butyl-4,6-dimethylphenol, 2,4-Di-t-butyl-6-methylphenol and 2,4,6-Tri-t-butylphenol with Nitrogen Dioxide

1985 ◽  
Vol 38 (1) ◽  
pp. 161 ◽  
Author(s):  
MP Hartshorn ◽  
WT Robinson ◽  
KH Sutton ◽  
J Vaughan
Keyword(s):  
Nitrogen Dioxide ◽  
Crystal Structures ◽  
Similar Reaction ◽  
X Ray

Reaction of 2-t-butyl-4,6-dimethylphenol(10) with nitrogen dioxide in benzene gives the C4-epimeric 4,5,6-trinitrocyclohex-2-enones (13) and (14). In contrast, similar reaction of 2,4-di-t-butyl-6-methyl-phenol (11) gives substituted cyclohex-3-enones, 2,5,6-trinitro ketones (20)- (23), 2-hydroxy-5,6-dinitro ketones (27) and (28) and the 6-hydroxy- 2,5-dinitro ketone (29). Reaction of 2,4,6-tri-t-butylphenol (12) with nitrogen dioxide gives initially the 4-nitro dienone (35), but de-t- butylated products (36) and (37) are formed in long-term reactions. X- ray crystal structures are reported for compounds (13),(14),(21),(22), (23), (27), (28) and (29).

scholarly journals Oxo-Bridged (Haloarylimido)[tris(3,5-dimethylpyrazolyl)borato]- molybdenum(V) Complexes: Crystal Structures of Geometric Isomers of [MoTp*(O)Cl](μ-O)[MoTp*(Cl)(≡NC6H4Br)]

2005 ◽  
Vol 60 (1) ◽  
pp. 15-21 ◽  
Author(s):  
Isil Topaloglu-Sozuer ◽  
Seckiner Dulger Irdem ◽  
John J. Jeffery ◽  
Hayrullah Hamidov ◽  
Ozan Sanlı Senturk
Keyword(s):  
Nmr Spectroscopy ◽  
Crystal Structures ◽  
Structure Analysis ◽  
Crystalline Solid ◽  
Similar Reaction ◽  
Geometric Isomers ◽  
X Ray ◽  
H Nmr ◽  
New Compounds

The reaction between [MoTp∗(O)Cl2], [Tp* = hydrotris(3,5-dimetylpyrazol-1-yl)borate] and 4-bromoaniline in refluxing toluene gave geometric isomers of [MoTp*(O)Cl](μ-O)[MoTp*(Cl) (≡NC6H4Br)] (1a, cis; 1b, trans), but a similar reaction between [MoTp*(O)Cl2] and 4-chloroaniline yielded only one product, [MoTp*(O)Cl](μ-O)[MoTp∗(Cl)(≡NC6H4Cl)] (2) as a red crystalline solid. The new compounds were characterized by microanalytical data, mass, IR and 1H NMR spectroscopy. The X-ray structure analysis of 1a and 1b revealed that the complexes are geometric isomers, the two chloro ligands being cis in 1a and trans in 1b. Both compounds have Mo-O-Mo linkages and nearly linear arylimido moieties.

Transmission electron microscope studies in special ceramics

1978 ◽  
Vol 36 (1) ◽  
pp. 268-269
Author(s):  
A. Zangvil ◽  
L.J. Gauckler ◽  
G. Schneider ◽  
M. Rühle
Keyword(s):  
Phase Diagrams ◽  
Crystal Structures ◽  
Thin Foil ◽  
Limited Extent ◽  
Complex Materials ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Electron Microscopes ◽  
Lattice Resolution

The use of high temperature special ceramics which are usually complex materials based on oxides, nitrides, carbides and borides of silicon and aluminum, is critically dependent on their thermomechanical and other physical properties. The investigations of the phase diagrams, crystal structures and microstructural features are essential for better understanding of the macro-properties. Phase diagrams and crystal structures have been studied mainly by X-ray diffraction (XRD). Transmission electron microscopy (TEM) has contributed to this field to a very limited extent; it has been used more extensively in the study of microstructure, phase transformations and lattice defects. Often only TEM can give solutions to numerous problems in the above fields, since the various phases exist in extremely fine grains and subgrain structures; single crystals of appreciable size are often not available. Examples with some of our experimental results from two multicomponent systems are presented here. The standard ion thinning technique was used for the preparation of thin foil samples, which were then investigated with JEOL 200A and Siemens ELMISKOP 102 (for the lattice resolution work) electron microscopes.

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