Structure of Alkyl Halides

Kepone and chlordane are synthesized from hexachlorocyclopentadiene and other five-membered-ring compounds. Show how these two pesticides are composed of two five-membered rings. 

In an alkyl halide, the halogen atom is bonded to an sp hybrid carbon atom. The halogen is more electronegative than carbon, and the C—X bond is polarized with a partial positive charge on carbon and a partial negative charge on the halogen. 

The carbon-halogen bond lengths increase as the halogen atoms become bigger (larger atomic radii) in the order 

These two effects oppose each other, with the larger halogens having longer bonds but weaker electronegativities. The overall result is that the bond dipole moments increase in the order 

TABLE 6-1 Molecular Dipole Moments of Methyl Halides  

Thomson11 jW Click Organic Interactive to use a web-based palette to draw structures for alkyl halides, based on their IUPAC names. 

Halomethane Bond length (pm) (kJ/mol) (kcal/mol) Dipole moment (D) 

In an earlier discus.sion of bond polarity in functional groups (Section 5.4), we noted that halogens are more electronegative than carbon. The C-X 

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Click Coached Tutorial Problems to practice Drawing Structures of Alkyl Halides, Alcohols, Ethers, and Amines. 

Describe and compare the structures of alkyl halides and aryl halides. (23.1)... 

THE STRUCTURES OF ALKYL HALIDES, ALCOHOLS, ETHERS, AND AMINES... 

Figure 5 Relationship between Katrp and structure of alkyl halide initiators, measured with Cu X/fPMA (X=Cl or Br) as catalyst with MeCN as solvent at 22 °C 3° red, 2° blue, 1° black R-Br solid, R-CI open, R bottom-half solid Amide , Phenyl , Ester , Nitrile o. Phenyl-ester 0, Allyl . Reprinted from Tang, W. Kwak, Y. Braunecker, W. etal. J. Am. Chem. Soc. 2008, 130,10702-10713, " with permission from the ACS.

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