How can a functional group affect

An aldehyde is a carbonyl in which the carbon atom is bonded to at least one hydrogen atom. Because the hydrogen atom is so small, the partial positive charge on the carbonyl carbon is very easy for other molecules to approach, making aldehydes a particularly reactive type of carbonyl. Aldehydes are versatile reactants for a wide variety of organic syntheses. Many aldehydes also have distinctive flavors and aromas.

For example, the flavor of cinnamon is primarily due to the molecule cinnamaldehyde, and vanillin is the aldehyde most responsible for the smell and taste of vanilla extract. A special aldehyde is the molecule in which the carbonyl is bonded to two hydrogen atoms.

This molecule, called formaldehyde, has a wide variety of uses. By itself, it can be used as a tissue preservative or as a very harsh disinfectant.

It is also used as a precursor to various materials, including plastics, resins, and other polymers. Ketones undergo most of the same reactions as aldehydes, but they tend to be slightly less reactive. This ketone is commonly used to remove fingernail polish and serves as an industrial solvent. Methyl ethyl ketone is used as a paint stripper and a solvent.

Ketones are also used in the production of various polymers, either as a building block or as a solvent. As the name implies, carboxylic acids are weak acids. The reason for this is the relative stability of the resulting anion. A carboxylate ion see figure below , in which the negative charge is spread over two different oxygen atoms through resonance structures, is more stable than an isolated oxygen-centered anion.

The carboxylic acid and carboxylate ion are interchangeable. Carboxylate ions are often present in amino acids. Carboxylic acids are used in a variety of environments. Formic acid acts as a protective chemical for many stinging insects and plants. Acetic acid gives vinegar its characteristic smell and flavor and is a fundamental biological and industrial building block. Carboxylic acids with longer carbon chains fatty acids are used by animals as a way of storing energy and are widely used in the manufacture of soaps.

Some compounds contain multiple carboxylic acids within a single molecule. For example, citric acid three carboxyl groups is especially abundant in citrus fruits and it used as a flavoring and preservative in many foods and beverages. An ester is similar to a carboxylic acid, in that it contains a carbonyl where the carbon is bonded to one additional oxygen atom and one carbon or hydrogen atom.

However, the second oxygen atom is bonded to another carbon instead of to an acidic hydrogen atom. Structurally, carboxylic acids and esters are related to one another in the same way as alcohols and ethers. Esters can be formed by heating carboxylic acids and alcohols in the presence of an acid catalyst.

This process is reversible, and the starting materials can be regenerated by reacting an ester with water in the presence of a weak base. Some esters have very pleasant odors, so they are used in the manufacture of many perfumes.

Hydrogen bonds between functional groups within the same molecule or between different molecules are important to the function of many macromolecules and help them to fold properly and maintain the appropriate shape needed to function correctly. Hydrogen bonds are also involved in various recognition processes, such as DNA complementary base pairing and the binding of an enzyme to its substrate. Boundless vets and curates high-quality, openly licensed content from around the Internet.

This particular resource used the following sources:. Skip to main content. Organic Chemistry. With over twenty million known organic compounds in existence, it would be very challenging to memorize chemical reactions for each one.

Fortunately, molecules with similar functional groups tend to undergo similar reactions. A functional group is defined as an atom or group of atoms within a molecule that has similar chemical properties whenever it appears in various compounds. Even if other parts of the molecule are quite different, certain functional groups tend to react in certain ways. We've already looked at alkanes, but they are generally unreactive.

This weak acid behavior results in the formation in an alkoxide salt and a water molecule. Hydroxyl groups alone are not considered good leaving groups. Often, their participation in nucleophilic substitution reactions is instigated by the protonation of the oxygen atom, leading to the formation a water moiety—a better leaving group. Alcohols can react with carboxylic acids to form an ester, and they can be oxidized to aldehydes or carboxylic acids.

Alcohols have many uses in our everyday world. They are found in beverages, antifreeze, antiseptics, and fuels. They can be used as preservatives for specimens in science, and they can be used in industry as reagents and solvents because they display an ability to dissolve both polar and non-polar substances.

Ethers are a class of organic compounds characterized by an oxygen atom connected to two alkyl or aryl groups. Ethers are a class of organic compounds that contain an ether group.

An ether group is an oxygen atom connected to two alkyl or aryl groups. The C-O-C linkage is characterized by bond angles of The oxygen of the ether is more electronegative than the carbons. Thus, the alpha hydrogens are more acidic than in regular hydrocarbon chains. Ethers : The general structure of an ether. The substituents can be, but do not need to be, the same. There are two ways to name ethers.

If the two alkyl groups are identical, the ether is called di[alkyl] ether. For example, diethyl ether is the ether with an ethyl group on each side of the oxygen atom. This way, the form is: [short alkyl chain][oxy][long alkyl chain]. In cyclic ethers, the stem of the compound is known as a oxacycloalkane.

An example is oxacyclopentane, a five-membered ring in which there are four carbon atoms and one oxygen atom. It is a common organic solvent that is miscible with water. Ethers are rather nonpolar due to the presence of an alkyl group on either side of the central oxygen. The presence of the bulky alkyl groups that are adjacent to it means that the oxygen atom is largely unable to participate in hydrogen bonding. Ethers, therefore, have lower boiling points compared to alcohols of similar molecular weight.

However, as the alkyl chain of the ethers becomes longer, the difference in boiling points becomes smaller. This is due to the effect of increased Van der Waals interactions as the number of carbons increases, and therefore the number of electrons increases as well. The two lone pairs of electrons present on the oxygen atoms make it possible for ethers to form hydrogen bonds with water.

Ethers are more polar than alkenes, but not as polar as esters, alcohols or amides of comparable structures. Ethers have relatively low chemical reactivity, but they are still more reactive than alkanes. Although they resist undergoing hydrolysis, they are often cleaved by acids, which results in the formation of an alkyl halide and an alcohol. Ethers tend to form peroxides in the presence of oxygen or air. Ethers can serve as Lewis and Bronsted bases, serving to donate electrons in reactions, or accept protons.

Keto-enol tautomers : There exists an equilibrium between the ketone and the enol forms, which involves a shifting of the double bond and the movement of a proton. When a carbonyl functional group is placed within a molecule, it is known as a ketone. Ketone : A ketone is a type of organic compound where a carbonyl group bonds to two other carbon atoms of the carbon backbone. The ketone carbon is sp 2 hybridized, and it adopts a trigonal planar geometry around the ketonic carbon.

Due to the carbonyl group, ketones are polar and are able to interact with other compounds through hydrogen bonding; this hydrogen bond capability makes ketones more soluble in water than related methylene compounds.

Ketones are not usually hydrogen bond donors, and they tend not to exhibit intermolecular attractions with other ketones. As a result, ketones are often more volatile than alcohols and carboxylic acids of comparable molecular weights.

Ketones have alpha -hydrogens which participate in keto-enol tautomerism. In the presence of a strong base, enolate formation and subsequent deprotonation of the enolate will occur. An aldehyde is an organic compound that contains a carbonyl group with the central carbon bonded to a hydrogen and R group R-CHO. Aldehydes differ from ketones in that the carbonyl is placed at the end of the carbon skeleton rather than between two carbon atoms of the backbone.

Like ketones, aldehydes are sp 2 hybridized and can exist in the keto or enol tautomer. If the location of the aldehyde must be specified, a number can be used in between the parent chain and suffix, or at the beginning of the compound name. Both aldehydes and ketones exist in an equilibrium with their enol forms; the enol form is defined as an alkene with a hydroxyl group affixed to one of the carbon atoms composing the double bond.

The keto form predominates at equilibrium for most ketones. However, the enol form is important for some reactions because the deprotonated enolate form is a strong nucleophile. The equilibrium is strongly thermodynamically driven, and at room temperature the keto form is favored.

The interconversion can be catalyzed by the presence of either an acid or a base. Keto-enol tautomerism : The interconversion between the two forms can be catalyzed by an acid or a base.

Both ketones and aldehydes can be identified by spectroscopic methods. They display strong CO absorption bands near cm In NMR spectroscopy, the carbonyl hydrogen shows a strong absorption peak, and any coupling to protons on the alpha carbon will also show strong signals. Ketones and aldehydes can both be readily reduced to alcohols, usually in the presence of a strong reducing agent such as sodium borohydride.

In the presence of strong oxidizing agents, they can be oxidized to carboxylic acids.