Xylene structure

An observed P/C/P bond angle of about 137° in crystalline Ph3P=C=PPh3 indicates a contribution from three structures (6.437). On the other hand, the P/C/P bond angle of 180° indicates a predominantly linear xylene structure for (6.438) (Figure 6.11). 

Alexandridis P, Olsson U and Lindman B 1997 Structural polymorphism of amphiphilic copolymers Six lyotropic liquid crystalline and two solution phases in a poly(oxybutylene)-poly(oxyethylene)-water-xylene system Langmuir 23-34... 

Fnedel-Crafts acylation of the individual isomers of xylene with acetyl chlonde and alu minum chloride yields a single product different for each xylene isomer in high yield in each case Write the structures of the products of acetylation of o m and p xylene... 

Figure 8.7. (a) Idealised view of a shish-kebab structure (after Pennings ei cil. 1970, Macklcy and Keller 1975). (b) Shish kebabs generated in a llowing solution of polyethylene in xylene (after... 

The major aromatics (organics having at least one ring structure with six carbon atoms) manufactured include benzene, toluene, xylene, and naphthalene. Other aromatics manufactured include phenol, chlorobenzene, styrene, phthalic and maleic anhydride, nitrobenzene, and aniline. Benzene is generally recovered from cracker streams at petrochemical plants and is used for the manufacture of phenol, styrene, aniline, nitrobenzene, sulfonated detergents, pesticides such as hexachlorobenzene, cyclohexane (an important intermediate in synthetic fiber manufacture), and caprolactam, used in the manufacture of nylon. Benzene is also used as a general purpose solvent. 

Aromatic — organic molecular structure having the benzene ring (C H ) as the basic unit (e.g., toluene, xylene). 

Ti in [Ti(> 2-Cl04)4] and Ni" in [Ni(>j -C104)L2] where L is a chiral bidenlate organic ligand.Sometimes both and modes occur in the same compound. The biden-latc bridging mode occurs in the silver complex [Ag /x,>j -00(0)20- (m-xylene)2]- The structure of appropriate segments of some of these compounds arc in Fig. 17.23. The distinction between coordinated and non-coordinaied ( ionic ) perchlorate is sometimes hard to make and there is an almost continuous... 

Sodium methyl mercaptide in xylene was reported to react (25°, 2 hr) in a stepwise fashion with 3,5-dichloro-as-triazine to yield the 3-methylthio-5-chloro and then (70°, 2 hr) the 3,5-bis-methylthio derivatives. However, the structure of the former is very likely to be 307. With dimethylamine in benzene (25°, 5 min), ethyleneimine in ether (25°, 3 min), and alcoholic ammonia (25°, few min), this dichloro derivative was assumed to form 3-amino derivatives. The high reactivity of as-triazines is demonstrated by the facile ethoxylation... 

The solid state structure of (3>S,8 Sj-10-(8-amino-6-azaspiro[3,4]octan-6-yl)-9-fluoro-3-methyl-7-oxo-2,3-dihydro-7//-pyrido[l,2,3-dfe]-l,4-benzoxa-zine-6-carboxylic acid (218) was determined by X-ray diffraction study (98CPB1710). The structure of 6,10-dihydropyrido[2,l-c][l,4]benzoxazine-6,10-dione 219 was established by X-ray diffraction analysis. It contains a crystal solvate with /j-xylene (99MI40). 

Chemical Name a -[[(1,1-Dlmethylethyl)amino]methyl]-4-hydroxy-1,3-benzenedimethanol Common Name Salbutamol a -tert-butylaminomethyl-4-hydroxy-m-xylene-ai,Q 3.diol Structural Formula ciIjOH... 

Although many of the aromatic compounds based on benzene have pleasant odors, they are usually toxic, and some are carcinogenic. Volatile aromatic hydrocarbons are highly flammable and burn with a luminous, sooty flame. The effects of molecular size (in simple arenes as well as in substituted aromatics) and of molecular symmetry (e.g., xylene isomers) are noticeable in physical properties [48, p. 212 49, p. 375 50, p. 41]. Since the hybrid bonds of benzene rings are as stable as the single bonds in alkanes, aromatic compounds can participate in chemical reactions without disrupting the ring structure. 

Increasing the octane number of a low-octane naphtha fraction is achieved by changing the molecular structure of the low octane number components. Many reactions are responsible for this change, such as the dehydrogenation of naphthenes and the dehydrocyclization of paraffins to aromatics. Catalytic reforming is considered the key process for obtaining benzene, toluene, and xylenes (BTX). These aromatics are important intermediates for the production of many chemicals. 

In what ratio would you expect the three products to be formed if o-xylene is a resonance hybrid of two structures The actual ratio found was 3 parts glyoxal, 1 part 2,3-butanedione, and 2 parts pyruvaldehyde. What conclusions can you draw about the structure of o-xylene ... 

Heating the components in xylene for 8 hours with azeotropic removal of the water formed gives a product which was assigned structure 6A, 2-methyl-3//-pyrido[2,3-6][l, 4]diazepin-4(5//)-one, on the basis of its H NMR spectrum an isomer, 4-methyl-l //-pyrido[2,3-fi][l,4]dia-zepin-2(3//)-one (7 A), is obtained when the components are heated without solvent at 180C for 15 minutes (no further details were reported.)... 

Ortho-Xylene Ozonide. C8H10O6 (probable structural formulae are shown in Ref 2), colorl crysts. 

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