Name: ether solubility and boiling points
Uploaded: 2025-05-22T09:05:33.000Z
Duration: 2 min 17 s
Channel: JoVE

Ethers are colorless liquids with a pleasant smell, except for dimethyl ether and ethyl methyl ether which are gases at room temperature.
Ethers are polar molecules because of the difference in electronegativity between oxygen and carbon atoms.
Moreover, the bent geometry of the molecule results in a net dipole moment, implying that weak intermolecular dipole&#8211;dipole interactions exist between them.
Consequently, the boiling points of ethers are significantly lower than the isomeric alcohols but often close to those of hydrocarbons of comparable molecular weight.
For example, dimethyl ether, ethanol, and propane have similar molecular weights but considerably different boiling points.
The difference in the boiling points of ethers and alcohols arises from the fact that ethers, unlike alcohols, fail to engage in intermolecular hydrogen bonding. They lack a hydrogen atom bonded to the oxygen and thus cannot act as hydrogen bond donors.
The slightly higher boiling points of ethers than the comparable hydrocarbons can be attributed to the net dipole moment of ethers.
Additionally, ethers with larger alkyl groups have higher boiling points due to the intermolecular London dispersion forces, which become more assertive with increasing molecular mass and larger surface area.
The solubility of ethers is dictated by their ability to act as hydrogen bond acceptors. Ethers can form hydrogen bonds with water due to the electronegative oxygen atom, making them water-soluble.
The solubility of ethers, however, decreases with an increase in the number of carbon atoms. This is because the relative increase in hydrocarbon portions decreases the propensity of hydrogen bonding with water molecules.
Overall, ethers are relatively unreactive and make excellent solvents for a variety of organic reactions. Their low boiling points make them highly volatile, therefore they evaporate quickly after a reaction is complete.

physical properties of ethers

Physical Properties of Ethers

<h4>Overview</h4>
An ether molecule has a net dipole moment due to the polarity of C&#8211;O bonds. Subsequently, boiling points of ethers are lower than those of alcohols of comparable molecular weight and slightly higher than those of hydrocarbons of comparable molecular weight (Table 1).
Ethers can act as hydrogen bond acceptors, making them more water-soluble than hydrocarbons, but since ethers cannot act as hydrogen bond donors, they are much less soluble in water than alcohols. Ethers are considered good solvents because of their ability to form hydrogen bonds with other molecules, combined with the London Dispersion forces between the alkyl groups bonded to oxygen. Ethers have high volatility and can quickly evaporate during the isolation of reaction products.
Table 1. Comparison of Boiling Points of Ethers, Alcohols, and Hydrocarbons
<table style="margin-left: auto; margin-right: auto;">
	<tbody style="border: 1px solid black;">
		<tr>
			<td style="color: black; border: 1px solid black; text-align: center;">Name</td>
			<td style="color: black; border: 1px solid black; text-align: center;"> Structural Formula </td>
			<td style="color: black; border: 1px solid black; text-align: center;">Molecular weight (g/mol)</td>
			<td style="color: black; border: 1px solid black; text-align: center;"> bp (&#176;C)</td>
		</tr>
		<tr>
			<td style="color: black; border: 1px solid black; text-align: center;">Dimethyl ether</td>
			<td style="color: black; border: 1px solid black; text-align: center;"><img alt="Ethyl ether structural formula: H3C-O-CH3, molecular chemistry diagram." src="/files/ftp_upload/11722/11722_PT_Figure_1.svg" style="text-align: center; height: 20px;" data-altupdatedat="1754904545000" data-alt="Ethyl methyl ether chemical structure formula H3C-O-CH3." /></td>
			<td style="color: black; border: 1px solid black; text-align: center;">46</td>
			<td style="color: black; border: 1px solid black; text-align: center;">&#8722;25</td>
		</tr>
		<tr>
			<td style="color: black; border: 1px solid black; text-align: center;">Ethanol</td>
			<td style="color: black; border: 1px solid black; text-align: center;"><img alt="Chemical structure of ethanol, CH3CH2OH, formula diagram for organic chemistry." src="/files/ftp_upload/11722/11722_PT_Figure_2.svg" style="text-align: center; height: 20px;" data-altupdatedat="1754904545000" data-alt="Ethyl alcohol chemical structure, CH&#8323;CH&#8322;OH, organic chemistry formula." /></td>
			<td style="color: black; border: 1px solid black; text-align: center;">46</td>
			<td style="color: black; border: 1px solid black; text-align: center;">78</td>
		</tr>
		<tr>
			<td style="color: black; border: 1px solid black; text-align: center;">Propane</td>
			<td style="color: black; border: 1px solid black; text-align: center;"><img alt="Chemical structure of propane molecule, CH3-CH2-CH3, linear formula representation." src="/files/ftp_upload/11722/11722_PT_Figure_3.svg" style="text-align: center; height: 20px;" data-altupdatedat="1754904545000" data-alt="Propane molecular structure, chemical formula CH3-CH2-CH3, organic chemistry representation." /></td>
			<td style="color: black; border: 1px solid black; text-align: center;">44</td>
			<td style="color: black; border: 1px solid black; text-align: center;">&#8722;42</td>
		</tr>
		<tr>
			<td style="color: black; border: 1px solid black; text-align: center;">Diethyl ether</td>
			<td style="color: black; border: 1px solid black; text-align: center;"><img alt="Ethyl ether molecular structure, C4H10O, displayed as chemical formula diagram." src="/files/ftp_upload/11722/11722_PT_Figure_4.svg" style="text-align: center; height: 20px;" data-altupdatedat="1754904545000" data-alt="Ethyl ether molecular structure formula; organic chemistry diagram; C4H10O bonds depicted." /></td>
			<td style="color: black; border: 1px solid black; text-align: center;">74</td>
			<td style="color: black; border: 1px solid black; text-align: center;">35</td>
		</tr>
		<tr>
			<td style="color: black; border: 1px solid black; text-align: center;">1-Butanol</td>
			<td style="color: black; border: 1px solid black; text-align: center;"><img alt="Chemical structure of butanol; molecule diagram with OH functional group, illustrating organic chemistry." src="/files/ftp_upload/11722/11722_PT_Figure_5.svg" style="text-align: center; height: 20px;" data-altupdatedat="1754904545000" data-alt="Butanol chemical structure, formula diagram, organic compound, alcohol group illustration." /></td>
			<td style="color: black; border: 1px solid black; text-align: center;">74</td>
			<td style="color: black; border: 1px solid black; text-align: center;">118</td>
		</tr>
		<tr>
			<td style="color: black; border: 1px solid black; text-align: center;">Pentane</td>
			<td style="color: black; border: 1px solid black; text-align: center;"><img alt="Straight-chain alkane chemical structure, pentane formula, molecular diagram." src="/files/ftp_upload/11722/11722_PT_Figure_6.svg" style="text-align: center; height: 20px;" data-altupdatedat="1754904545000" data-alt="Straight-chain hydrocarbon formula; pentane molecular structure; organic chemistry concept." /></td>
			<td style="color: black; border: 1px solid black; text-align: center;">72</td>
			<td style="color: black; border: 1px solid black; text-align: center;">36</td>
		</tr>
	</tbody>
</table>

Overview
An ether molecule has a net dipole moment due to the polarity of C&#8211;O bonds. Subsequently, boiling points of ethers are lower than those of ...

Education

JoVE Core

Organic Chemistry

Unit 1

Ethers, Epoxides, Sulfides

KEY TERMS AND CONCEPTS

ether solubility and boiling points

Ethers have a net dipole moment because the C-O bonds are polar. This polarity helps explain why their boiling points are lower than alcohols with similar molecular weight and slightly higher than hydrocarbons with similar molecular weight.

Ethers can also accept hydrogen bonds, which makes them more water-soluble than hydrocarbons. However, they cannot donate hydrogen bonds, so they are much less soluble in water than alcohols. Their mix of hydrogen bonding with other molecules and London dispersion forces between the alkyl groups attached to oxygen also makes ethers useful solvents.

Ethers are highly volatile, so they can evaporate quickly during the isolation of reaction products. The comparison data for dimethyl ether, ethanol, propane, diethyl ether, 1-butanol, and pentane show how ethers fit between alcohols and hydrocarbons in boiling point.

Ether Solubility and Boiling Points

structure and nomenclature of ethers

Ethers: Bonding, Types, and Naming

Ethers are organic compounds with an oxygen atom bonded to two groups. Those groups may be the same or different, and they can be alkyl, aryl, or vinyl groups. In dimethyl ether, the simplest ether, the C–O–C link has an angle of about 110.3 degrees. The oxygen is sp3-hybridized, and the C–O distance is about 140 pm. Ethers are classified by the groups attached to the oxygen atom. Symmetrical ethers have identical groups on both sides, such as dipropyl ether and diphenyl ether. Unsymmetrical...

Ethers have a net dipole moment because the C-O bonds are polar. This polarity helps explain why their boiling points are lower than alcohols with similar molecular weight and slightly higher than hydrocarbons with similar molecular weight. Ethers can also accept hydrogen bonds, which makes them more water-soluble than hydrocarbons. However, they cannot donate hydrogen bonds, so they are much less soluble in water than alcohols. Their mix of hydrogen bonding with other molecules and London...

ethers from alcohols: alcohol dehydration and williamson ether synthesis

ethers-from-alcohols-alcohol-dehydration-williamson-ether

Making Ethers by Dehydration and Synthesis

Ethers can be made from alcohols by dehydration and by Williamson ether synthesis. These two routes show how alcohols can act in different roles during ether formation. The first method uses a protic acid, while the second method uses an alkoxide ion and an alkyl halide. In alcohol dehydration, the alcohol loses water in the presence of a protic acid such as sulfuric acid. Ethanol gives ethoxyethane at 413 K, but it gives ethene at 443 K. This reaction is a nucleophilic substitution reaction,...

ethers from alkenes: alcohol addition and alkoxymercuration-demercuration

ethers-from-alkenes-alcohol-addition-alkoxymercuration

Making Ethers with Alkene Reactions

Ethers can be made from alkenes by adding alcohols under acidic or organomercury conditions. The two routes shown here are acid-catalyzed addition of alcohol to an alkene and alkoxymercuration-demercuration. Both methods start with an alkene and an alcohol and end with an ether. In acid-catalyzed addition, the alkene reacts with an excess of alcohol in the presence of an acid catalyst. Under the right conditions, the hydrogen adds to the less substituted carbon. This lets the alcohol group...

ethers to alkyl halides: acidic cleavage

Cleaving Ethers with HBr and HI

Ethers can be cleaved into alkyl halides when heated with strong acids such as HBr and HI. This reaction is useful because ethers are usually unreactive in direct nucleophilic substitution. Their alkoxy groups are strong bases, so they are poor leaving groups. The acid cleavage happens in two substitution steps. First, the ether is converted into one alkyl halide and one alcohol. Then the alcohol reacts with excess HX acid to form a second alkyl halide. The reaction pathway depends on the...

autoxidation of ethers to peroxides and hydroperoxides

autoxidation-of-ethers-to-peroxides-and-hydroperoxides

Why Stored Ethers Can Form Explosive Peroxides

Stored ethers can slowly turn dangerous because they react with oxygen in air and form peroxides. This process is called autoxidation, which means a compound oxidizes on its own while standing in air. Over time, ethers can produce hydroperoxides and dialkyl peroxides. These peroxide products can be explosive if they become concentrated or are heated. For that reason, ethers should be bought in small amounts, kept in tightly sealed containers, and used soon after opening. Careful storage helps...

crown ethers

Crown Ether Binding and Ion Solubility

Crown ethers are cyclic polyethers with several oxygen atoms arranged in a ring. Their ring shape gives them a crown-like form. Charles Pederson first synthesized the first crown ether at DuPont in 1967, and he later shared the 1987 Nobel Prize in Chemistry for that work. Crown ethers are named with the format x-crown-y. In this name, x is the total number of atoms in the ring, and y is the number of ether oxygen atoms. A common example is 18-crown-6. These molecules can bind specific alkali...

structure and nomenclature of epoxides

Epoxide Ring Strain and Naming Rules

Epoxides are three-membered cyclic ethers that contain two carbon atoms and one oxygen atom in the ring. Cyclic ethers are heterocyclic compounds, which means the ring includes atoms other than carbon. Their names depend on the number of carbon atoms in the ring. A three-membered cyclic ether is called an oxirane. Four-membered rings are called oxetane, five-membered rings are called oxolane, and six-membered rings are called oxane. Smaller rings have more angle strain, and the three-membered...

preparation of epoxides

How Alkenes Form Epoxides

Alkenes can form epoxides through oxidation. This reaction can happen with air, peroxy acids, hypochlorous acids, or halohydrin cyclization. Epoxides are three-membered oxygen rings, and they are common products in alkene chemistry. A common lab method uses a peroxy acid such as meta-chloroperoxybenzoic acid, or MCPBA. In this reaction, the carbon-carbon double bond is converted into an epoxide by adding electrophilic oxygen. Because the O-O bond in a peroxy acid is very weak, the oxygen adds...

sharpless epoxidation

Chiral Control in Sharpless Epoxidation

Sharpless epoxidation is a chiral reaction that converts allylic alcohols into epoxides. It was discovered by K. Barry Sharpless. The reaction is useful because it can favor one enantiomer, or mirror-image product, over the other. The key to this selectivity is a chiral catalyst. It is mainly a complex of titanium tetraisopropoxide and a tartrate ester with a specific stereoisomer, or 3D arrangement. The stereoisomer in the catalyst controls which enantiomer forms in excess. Using...

acid-catalyzed ring-opening of epoxides

Epoxide Ring Strain and Acidic Opening

Epoxide ring strain makes these three-membered ethers highly reactive. Because the ring is so strained, epoxides can open in reactions with halogen acids or with weak nucleophiles when a mild acid is present. The acid catalyst changes the epoxide oxygen into an oxonium ion, which is a better leaving group. This makes the ring-opening reaction possible. The reaction follows an S N 2 mechanism, and the protonated oxygen does not leave the molecule on its own. The product pattern depends on the...

base-catalyzed ring-opening of epoxides

Epoxide Ring Opening by Strong Nucleophiles

Epoxide ring opening by strong nucleophiles happens because epoxides have a highly strained three-membered ring. This strain makes them ready for nucleophilic substitution in either acid or base. In the base-catalyzed pathway, a strong nucleophile or base attacks the ring and opens it. Common nucleophiles for this reaction include sodium hydroxide, sodium alkoxide, sodium hydrosulfide, sodium cyanide, lithium aluminum hydride, and Grignard reagents. The attack follows an SN2 mechanism and...

structure and nomenclature of thiols and sulfides

structure-and-nomenclature-of-thiols-and-sulfides

Sulfur in Thiols and Sulfides

Thiols and sulfides are sulfur-based organic compounds. Thiols are sulfur analogs of alcohols, and sulfides are sulfur analogs of ethers. In thiols, the sulfur atom is written as RSH, where R is an alkyl group and SH is the functional group. Sulfides have a central sulfur atom bonded to two hydrocarbon groups, one on each side. These compounds can be symmetrical or asymmetrical, depending on the groups attached. Both thiols and sulfides have a bent shape, much like alcohols and ethers. The...

preparation and reactions of thiols

Thiols: Making and Oxidizing Sulfur Compounds

Thiols are sulfur compounds that can be made by nucleophilic substitution with alkyl halides. In one route, the hydrosulfide anion acts as the nucleophile. For example, bromobutane reacts with sodium hydrosulfide to form butanethiol. That direct method has a limitation. If excess alkyl halide is present, the thiol product can react again and form a sulfide as a by-product. A better route uses thiourea as the nucleophile. This reaction first gives an alkyl isothiourea salt as an intermediate.

preparation and reactions of sulfides

Sulfide Synthesis and Oxidation

Sulfides are sulfur compounds that contain two hydrocarbon groups attached to one sulfur atom. They are the sulfur analog of ethers, just as thiols are the sulfur analog of alcohols. Depending on the groups attached, sulfides may be symmetrical or asymmetrical. Symmetrical sulfides can be made by an S N 2 reaction. In this method, two equivalents of an alkyl halide react with one equivalent of sodium sulfide. Asymmetrical sulfides are prepared from thiols, an alkyl halide, and a base. This...

key terms and concepts

Explore why ethers sit between alcohols and hydrocarbons in boiling point, and how their polarity affects water solubility, volatility, and solvent use.

Ether Solubility and Boiling Points | JoVE K12

organic chemistry

JoVE Core Organic Chemistry explains basic concepts of stereochemistry, reactions, and mechanisms using concise and easy-to-understand animated video lessons. Additionally, the scientist-in-action videos demonstrate the application of related concepts in classical and original research experiments performed in today's laboratories worldwide.

Ether Solubility and Boiling Points

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