Physical properties of alkyl halides

For each pair of compounds, [xedict which compound has the higher boiling point. Check Table 6-2 ID see if your prediction was right, then explain why that compound has the higher boiling pdnt 

TABLE 6-2 Properties of Some Simple Alkyl Halide 1  

Compound Molecular Weight Boiling Point (°C) Density (g/mL) 

Space-filling drawings of the ethyl halides. The heavier halogens are larger, with much greater surface areas. 

When water is shaken with hexane, the two liquids separate into two phases. Show which compound is present in the top and which in the bottom [diase. When water is shaken with chloroform, a milar two-phase system results. Again, show which compound is present in each phase. Explain the difference in the two experiments. 

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Nomenclature Physical properties Interesting alkyl halides The polar carbon-halogen bond General features of nucleophilic substitution The leaving group The nucleophile Possible mechanisms for nucleophilic substitution Two mechanisms for nucleophilic substitution The S 2 mechanism Application Useful Snj2 reactions... 

Physical Properties of Alcohols and Alkyl Halides Intermolecular Forces... 

PHYSICAL PROPERTIES OF ALCOHOLS AND ALKYL HALIDES INTERMOLECULAR FORCES... 

Some recent studies have underlined the effect that certain physical properties of the reaction medium have in governing the nature and yields of the products obtained when indole Grignard reagents react with alkyl or alkynyl halides. Such factors include the basicity and dielectric constant of the medium and its ability to solvate any of the reacting species. ... 

Cyclic enone, 12 185 Cyclic ethers, 10 567, 569 12 663 polymerization, 14 271 Cyclic fatigue, in ceramics, 5 633-634 Cyclic gas generators, 6 786-787, 789, 827 Cyclic halides, 19 56 Cyclic hexakis(thio-l,4-phenylene), melt polymerization of, 23 705 Cyclic hydrocarbons, 13 687 Cyclic hydroxyalkyl alkyl peroxide, 18 454 Cyclic ion exchange operation, 14 408-413 Cyclic ketones, 12 176, 177 14 590-592. See also Cyclic 1,2-diketones physical properties of, 14 591t hydroxyalkyl hydroperoxides from, 18 450... 

In this section, you learned how to recognize, name, and draw members of the alcohol, alkyl halide, ether, and amine families. You also learned how to recognize some of the physical properties of these compounds. In the next section, you will learn about families of organic compounds with functional groups that contain the C=0 bond. 

The physical properties of unsubstituted aryl halides are much like those of the corresponding alkyl halides. Thus, boiling points, melting points, and solubilities of aryl halides are very similar to those of alkyl halides containing the same number of carbon atoms. 

Grosse, A.V., Wackher, R.C., Linn, C.B. (1940) Physical properties of the alkyl fluorides and a comparison of the alkyl fluorides with the other halides and with the alkyls of the elements of Period II. J. Phys. Chem. 44, 275-296. 

The carbon-halogen bond is slightly polar. Overall, however, an alkyl halide is not much more polar than an alkane, so the physical properties of an alkyl halide are not very different from those of an alkane of similar molecular weight. For example, the boiling point of 1-chlorobutane (MW = 92.5 g/mol) is 78°C, whereas that of hexane (MW = 86 g/mol) is 69°C. In general, alkyl halides are insoluble in water. Because of the presence of the more massive halogen atom, the alkyl halide may be more dense than water. For example, when dichloromethane, a common laboratory solvent, and water are mixed, two layers are formed, with dichloromethane as the lower layer. 

It is easiest to talk about properties of organic compounds containing functional groups by comparing those compounds with alkanes, whose properties were discussed in Chapter 22. Table 23-2 lists some of the physical properties of certain alkanes and alkyl halides. 

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