Sulfur trioxide molecular structure

On being heated with sulfur trioxide in sulfuric acid 124 5 tetramethylbenzene was converted to a product of molecular formula C10H14O3S m 94% yield Suggest a reasonable structure for this product... 

Dyes, Dye Intermediates, and Naphthalene. Several thousand different synthetic dyes are known, having a total worldwide consumption of 298 million kg/yr (see Dyes and dye intermediates). Many dyes contain some form of sulfonate as —S03H, —S03Na, or — SC NH. Acid dyes, solvent dyes, basic dyes, disperse dyes, fiber-reactive dyes, and vat dyes can have one or more sulfonic acid groups incorporated into their molecular structure. The raw materials used for the manufacture of dyes are mainly aromatic hydrocarbons (67—74) and include benzene, toluene, naphthalene, anthracene, pyrene, phenol (qv), pyridine, and carbazole. Anthraquinone sulfonic acid is an important dye intermediate and is prepared by sulfonation of anthraquinone using sulfur trioxide and sulfuric acid. 

Organic substances such as methane, naphthalene, and sucrose, and inorganic substances such as iodine, sulfur trioxide, carbon dioxide, and ice are molecular solids. Salts such as sodium chloride, potassium nitrate, and magnesium sulfate have ionic bonding structures. All metal elements, such as copper, silver, and iron, have metallic bonds. Examples of covalent network solids are diamond, graphite, and silicon dioxide. 

Quantum chemical methods are valuable tools for studying atmospheric nucle-ation phenomena. Molecular geometries and binding energies computed using electronic structure methods can be used to determine potential parameters for classical molecular dynamic simulations, which in turn provide information on the dynamics and qualitative energetics of nucleation processes. Quantum chemistry calculations can also be used to obtain accurate and reliable information on the fundamental chemical and physical properties of molecular systems relevant to nucleation. Successful atmospheric applications include investigations on the hydration of sulfuric acid and the role of ammonia, sulfur trioxide and/or ions... 

The sulfur derivative (87) is 1000 times as sweet as sugar and without the bitter after-taste of saccharin however, it was discovered that N-alkylation of (87) removed the sweetness. On the other hand, in the saccharins (88a)-(88e) containing substituents in the 4-position and 6-position, sweetness was retained after N-alkylation. Many sulfamic acid derivatives are sweet, and there have been numerous studies of structure-taste relationships which have highlighted the importance of molecular shape and stereochemistry (see Chapter 9, p. 162). Two sulfamates which are commercial, non-nutritive sweeteners are cyclamate (85) and acesulfame potassium (86) (Figure 11). Cyclamate (85) is manufactured by refluixing cyclohexylamine either with triethylamine-sulfur trioxide in dichloromethane or with sulfamic acid (see Chapter 9, p. 162). 

Nevertheless, because of the dehydrating action of sulfur trioxide, higher-molecular structures are formed via anhydride bridges (Scheme 1). The anhydride bridges must, therefore, be hydrolyzed in the next step. For this purpose, the reaction mixture is... 

From the molecular structures shown here, identify the one that corresponds to each of the following species (a) chlorine gas, (b) propane, (c) nitrate ion, (d) sulfur trioxide, (e) methyl... 

The molecular structure of sulfur dioxide is angular, while the structure of the trioxide is trigonal planar. See Fig. 20.2. It is noteworthy that the bond distances in SO2 and SO3 are 5 or 6 pm shorter than in the monoxide, while the mean bond energies in SO2 and SO3 are respectively 3% greater and 9% smaller than the dissociation energy of the monoxide. These observations indicate that the SO bonds in these molecules are best described as double. 

Fig. 20.2. The gas phase molecular structures and S=0 bond energies of sulfur oxide, dioxide and trioxide.

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