Principles Of Drug Action 1, Spring 2005, Halogenated Hydrocarbons

Halogenated hydrocarbons are organic compounds consisting of C-C, C-H and C-X bonds where X is a halogen atom (F, Cl, Br, I). Carbon has a valence of four and thus requires four electrons or bonds to complete its octet in the neutral state. Hydrogen has a valence of one and thus requires a single electron or bond to complete its “duet” in the neutral state. Halogens have seven valence electrons and thus require a single electron or bond to complete its octet. Thus in halogenated hydrocarbons, carbon can form neutral bonding arrangements by forming single bonds with halogens, single bonds with hydrogen, and single, double or triple bonds with other carbons (or other atoms). This bonding order is illustrated for chloromethane shown below: