7/28/2019 BIOORG2 Anhydrides

1/3

Salih, Seth June 13, 2013Sanchez, Maria LouiseSarao, Patrick

BIOORG2 NO1

Anhydrides

Anhydrides are chemical compounds obtained by removing water from another

substance. They are a group of chemicals with molecules that include and Oxygen atom

bonded to two acylgroups. Acid anhydrides are formed from the removal of water from

an acid. Similarly, base anhydrides are formed from the removal of water from a base,

such as calcium oxide. The general formula of anhydrides is:

Common examples of anhydrides are acetic anhydride (CH3CO)2O, formic

anhydride C2H2O3, and propanoic anhydride C6H10O3. In naming anhydrides, take the

name of the parent acid or base and change it to anhydride. For example, ethanoic acid

forms ethanoic anhydride or acetic anhydride, and propanoic acid becomes propanoic

anhydride.

Due to the differing nature of the carbon chains attached to the Oxygen atom, the

properties of anhydrides vary. To make things easier, the group member chose

ethanoic anhydride as the example. Anhydrides are usually colorless liquids with certain

odors. However, some anhydrides are solid at room temperature, in the form of pellets

They cannot dissolve in water as this will revert them to their original forms: acids or

7/28/2019 BIOORG2 Anhydrides

2/3

bases, since water was originally removed from them. Their relatively high boiling points

are due to the dipole-dipole interactions. Despite this, they cannot form hydrogen

bonds.

In reacting to different reagents, the mechanism is fairly similar. The functional

group of anhydrides is an Oxygen atom bonded to two Carbon chains. When these

substances react with water, alcohols, and phenols, the common result is the formation

of the parent acid or base. Aside from this, the functional groups of the reagents bond to

the oxygen atom of the anhydride.

As with most chemicals, anhydrides also have certain applications in some fields.

Several acid anhydrides are used in modern industry. Acetic anhydride is commonly

used as a reagent for reactions involving certain organic compounds and is involved in

the production ofaspirinand celluloseacetate, which is used as a synthetic fiber and as

a substrate, or base, for the photosensitive chemicals in photographic film. Another

example is maleic anhydride (C2H2(CO)2O), which is used in the production of the

polyester resins in molding compounds and toner for laser printers and photocopiers.

http://www.wisegeek.com/what-is-aspirin.htmhttp://www.wisegeek.com/what-is-aspirin.htmhttp://www.wisegeek.com/what-is-aspirin.htmhttp://www.wisegeek.com/what-is-an-acetate.htmhttp://www.wisegeek.com/what-is-an-acetate.htmhttp://www.wisegeek.com/what-is-an-acetate.htmhttp://www.wisegeek.com/what-is-an-acetate.htmhttp://www.wisegeek.com/what-is-aspirin.htm

7/28/2019 BIOORG2 Anhydrides

3/3

Sources:

http://global.britannica.com/EBchecked/topic/25412/anhydride

http://www.ivy-rose.co.uk/Chemistry/Organic/Naming-Acid-Anhydrides.php

http://www.chemguide.co.uk/organicprops/anhydrides/background.html

http://www.wisegeek.com/what-is-an-acid-

anhydride.htmhttp://www.chemguide.co.uk/organicprops/anhydrides/oxygen.html