25.4-+Common+Functional+Groups+in+Organic+Compounds

= = 25.4: COMMON FUNCTIONAL GROUPS IN ORGANIC COMPOUNDS (or, how to tell the difference between lots of organic substances that can start to look the same after a while)

So this section was the different types of organic compounds and how you as an AP student can differentiate them. There was this very helpful chart in the book that was a quick snapshot of all of the different functional groups covered. This can be found on page 1071 in the Brown-LeMay book (-->), but I found a file of a table that is very similar. So follow this link: http://academic.pgcc.edu/~ssinex/MolVis/FuncGroups.pdf Here are the ones we will cover: Alkene, Alkyne, Alcohol, Ether, Haloalkane, Amine, Aldehyde, Ketone, Carboxylic Acid, Ester, and Amide. the basis of which is in Alkanes, Alkenes, and Alkynes, Alex's chapter.

This flow chart should help on identifying the organic groups:

ALKENE
For all alkenes with 4 or more carbons, there is **structural isomerism**. In the example of butENE, there are three different ways to align the compound, all correct. We studied this earlier in the year, but it is a good rule that isomerism occurs without fail with 4 or more carbons.
 * Alkenes** contain a double bond between Carbon atoms.. When naming these, use the suffix -ENE. They are generally reactive and common reactions add halogens or Hydrogens. A rule for finding them is that C(n)H(2n), making it easy to spot them.

ALKYNE

 * [[image:alkyne.gif width="125" height="35" align="right" caption="a basic alkyne compound (ethyne)"]]Alkynes** are similar to alkenes, but have a triple bond between the carbons instead of a double bond. It's suffix is -YNE, demonstrated by the example C2H2, or ethYNE (also known as acetylene). Like Alkenes, they are generally reactive and common reactions add halogens or hydrogens. They also show a higher tendency to polymerize than alkenes.

ALCOHOL
Alcohols are more soluble in polar solvents like water than alkanes, and can participate in hydrogen bonding because of this. They also have higher boiling points than alkane forms of the compounds. Polyhydroxyls are types of alcohols with many -OH replacements, like glycerol. Phenol is the smallest compound with -OH replacement and aromatic ring (the aromatic group makes it about one million times more acidic than ethanol). Because of the common suffix for the functional group, it is often used to name even complex molecules like cholesterOL. Alcohols are used commonly in antifreeze, aftershave, and cold medicines.
 * [[image:alcohol.png align="right" caption="This is the end of the compound where the hydroxyl group is located. Note the bond angle, making this pair of bonds a "bent" appearance"]]Alcohols** contain a carbon bonded to an Oxygen bonded to a hydrogen, with oxygen maintaining a lone pair, also known as the **hydroxyl functional group**. The suffix of this functional group is -OL, and common compounds are methanOL, ethanOL, propanOL, and cholesterOL. They are formed by replacing one of the hydrogens of an Alkene with the hydroxyl group.



ETHER (What's invisible and smells like carrots? why, the ETHER bunny, of course!)
EXAMPLE: CH3CH2-OH + H-OCH2CH3 --> CH3CH2-O-CH2CH3 + H2O This is an example of a **condensation reaction**, and is catalyzed by sulfuric acid. Ethers are commonly used as solvents.
 * Ethers** are a functional group that is at the center of a compound, of two **alkyl** groups (hydrocarbons) bonded to one oxygen. To name an ether, simply add ETHER to the end, exhibited by ethers "dimethyl ETHER" and "methyl phenyl ETHER" (anisole). Ethers can be formed from two molecules of alcohol by splitting out water.

AMINE
**Amines** contain a Nitrogen bonded to the carbon, and its suffix is -AMINE, making common compounds of this group ethylAMINE or ethanolAMINE. These groups have their basis in Ammonia, where one of the hydrogens is replaced by an alkyl group like an alcohol or alkene. Because of this they are considered **chiral**, meaning that there are four atoms bonded to the nitrogen. They are organic bases. The general formula is R3N, and amines with an H-N bond can react in a condensation reaction with **carboxylic acid**s to form amides.

ALDEHYDE[[image:forma;.jpg width="141" height="102" align="right" caption="common aldehyde"]]

 * Aldehydes** contain an oxygen double bonded to carbon, called the **carbonyl group** with the Ketones. These are created by oxidizing alcohols, a reaction that can create ozine and hydrogen peroxide. The suffix for aldehydes is -AL, with common ones being ethanAL (acetaldehyde), or methanal (commonly known as formaldehyde). Aldehydes also enervate in the air using a process called **autoxidation**.

KETONES

 * Ketones** are in the same group as aldehydes, the **carbonyl group**, where the double bond O=C is at the center of the compound with carbons single bonded on each side of the carbon. The suffix is -ONE, like propanone (acetone), acetylacetone, and muscone. Its common compounds include spearmint leaves and caraway. Ketones were less reactive and used extensively as **solvents**. It dissolves a wide range of organic substances and is miscible in water.



CARBOXYLIC ACID
Formula: Carboxylic Acid + alcohol --> esters (condensation reaction) The reaction of methanol with carbon monoxide to produce CH3COOH is called **carbonylation**.
 * Carboxylic Acids** contain COOH (carboxyl function group), and their suffix is -OIC ACID, with examples like ethanOIC ACID and benzOIC ACID. They are **Brønsted–Lowry acids**, and are created by the oxidation of alcohols.

ESTER

 * Esters** have an oxygen which interrupts a carbon-carbon bond and one of those carbons has an oxygen instead of hydrogen double bonded to it. In order to name esters, first use the alcohol derivative, then the acid derivative, ending in -OATE (for example, methyl ethanOATE). They are responsible for the smells of fruit like bananas (pentyl acetate). The **hydrolysis** of an ester with a base causes **saponification** (i.e. the reaction to make soap).

AMIDES

 * [[image:amide.gif align="right"]]Amides** are like amines, however the carbon bonded to the nitrogen is also double bonded to an oxygen. This functional group also is formatted like carboxylic acid with NR2 instead of -OH. The naming suffix is -AMIDE (for example, ethanAMIDE). In comparison to **amines**, they are very weak bases, but are less soluble than amines.

**http://www.youtube.com/watch?v=mAjrnZ-znkY**
 * AND NOW, TO HELP YOU REMEMBER....**
 * "It's a family thing..."**

RESOURCES:
 * Understanding Chemistry: Properties of Organic Compounds
 * Overview of Organic Compounds
 * Chart of Organic Functional Groups :
 * Functional Group Chart (another one) :pdf
 * Brown-LeMay textbook chapter 25

REFERENCES:
 * Brown, Theodore L., et al. __Chemistry: The Central Science__. 11th ed. Upper Saddle River: Pearson Prentice Hall, 2009. Print.
 * Clark, Jim. "Properties of Organic Compounds". __Understanding Chemistry__. 2004. 20 March 2011. 
 * Reusch, William. "Naming Organic Compounds". __Nomenclature__. 1999. 21March 2011. <http://www2.chemistry.msu.edu/faculty/reusch/VirtTxtJml/nomen1.htm >