Hydrocarbon Derivatives

Hydrocarbon Derivatives 

Hydrocarbon derivatives are molecules that are fundamentally hydrocarbons, but have additional atoms or groups of atoms called functional groups.  Hydrocarbon derivatives are primarily made up of Alcohols, Aldehydes and Ketones, Carboxylic Acids and Esters, and Amines.

Alcohols are characterized by the presence of the hydroxyl group (-OH).  The systemic name for an alcohol is obtained by replacing the final –e of the parent hydrocarbon by –ol.  Alcohols usually have much higher boiling points than might be expected from their molar masses.  Although there are many important alcohols, the simplest ones, methanol and ethanol, have the greatest commercial value.  Methanol is used as a starting material for the synthesis of acetic acid and many types of adhesives.  Fibers.  And plastics.  It also can be used as a motor fuel.  Methanol is highly toxic to humans and can lead to blindness and death if ingested.  Ethanol is the alcohol found in beverages such as beer, wine, and whiskey.

Aldehydes and Ketones contain the carbonyl group.  The carbonyl group is one type of double bond.  The unique properties and reactivity of Aldehydes and Ketones arise from their unique charge distribution.  The systemic name for aldehyde is obtained from the parent alkane by removing the final –e and adding –al­.  For ketones, the final –one replaces -e, and the number indicates the position of the carbonyl group where necessary.  Ketones often have useful solvent properties and are frequently used in industry for this purpose.  Aldehydes and ketones are most often produced commercially by the oxidation of alcohols.  Carboxylic acids and esters are characterized by the presence of the carboxyl group and have the general formula RCOOH.  These molecules are typically weak acids in aqueous solutions.  Organic acids are named from the parent alkane by dropping the final –e and adding –oic.  Many carboxylic acids are synthesized by oxidizing primary alcohols with a strong oxidizing agent.  A carboxylic acid reacts with an alcohol to form an ester and a water molecule.  Esters often have a sweet, fruity odor that s in contrast to the often-pungent odors of the parent carboxylic acids.

Amines are probably best viewed as derivatives of ammonia in which one or more N-H bonds are replaced by N-C bonds.  The resulting amines are classified as primary if one N-C bond is present, secondary is they contain two N-C bonds, and tertiary if all three N-H bonds in NH3 have been replaced by N-C bonds.  Many amines have unpleasant fish-like odors.