Haloalkane introduction
Haloalkanes (alkyl halides) are compounds in which one or more hydrogens of a saturated hydrocarbon are replaced by halogen. As shown at the right several polyhaloalkanes are used commercially in various applications.
Recently some commercial uses of haloalkanes have been curtailed due to their carcinogenicity (CCl4) and the role that they have been postulated to play in destruction of the ozone layer.
Despite these negative factors, haloalkanes are often used as intermediate compounds in multistep syntheses of organic compounds. The mode of preparation and/or reactivity of a haloalkane may depend on the degree of substitution (number of carbons) at the carbon bearing halogen. Thus it is useful to classify haloalkanes as shown.
In general, organic chemists classify to make it easier to get the “big picture“ and apply known results to predicting the outcome of reaction of a new compound with the same type of functional group.
ClCH2CH2Cl and CH2Cl2 solvents | CClF3 Freon - refrigerant |
F3C–CHBrCl halothane - anaesthetic | (–CF2CF2–)n Teflon nonstick polymer |
Recently some commercial uses of haloalkanes have been curtailed due to their carcinogenicity (CCl4) and the role that they have been postulated to play in destruction of the ozone layer.
Despite these negative factors, haloalkanes are often used as intermediate compounds in multistep syntheses of organic compounds. The mode of preparation and/or reactivity of a haloalkane may depend on the degree of substitution (number of carbons) at the carbon bearing halogen. Thus it is useful to classify haloalkanes as shown.
In general, organic chemists classify to make it easier to get the “big picture“ and apply known results to predicting the outcome of reaction of a new compound with the same type of functional group.
| primary | one carbon at C bearing halogen | CH3CH2Br |
| secondary | two carbons at C bearing halogen |  |
| tertiary | three carbons at C bearing halogen |  |