Transcript ETHER
ETHER Kayden Evans Taylor Segell Gabriela Torres 5p BASIC STRUCTURE Ethers always have to have an oxygen in the center. They can have hydrogen and carbon bound off of each side but the oxygen must remain in the middle. CHARACTERISTICS • Ether molecules cannot form hydrogen bonds with each other, making their boiling points low. • The C-O-C bond angle in the functional group is about 110°. • Ethers are slightly polar, more polar than alkenes but not as polar as alcohols, esters, or amides. CHARACTERISTICS • Because of the nature of the positive charge on the ether hydrogen atoms, the hydrogens cannot participate in hydrogen bonding. So, ethers only form hydrogen bonds to other molecules that have hydrogen atoms with strong partial positive charges. NOMENCLATURE "Simple" ethers: If both groups are simple alkyl groups, then the ether is usually named as alkyl alkyl ether If the two alkyl groups are the same, then it's a dialkyl ether Ex. CH3 CH2 O CH3 • Functional group is a simple ether, therefore use alkyl alkyl ether 1. First substituent is C1 alkane therefore alkyl = methyl 2. Second substituent is C2 alkane therefore alkyl = ethyl CH3 CH2 O CH3 = ethyl methyl ether Ex. CH3 CH2 O CH2 CH3 • Functional group is a simple ether, therefore use alkyl alkyl ether 1. Both substituents are C2 alkane therefore alkyl = ethyl 2. Since there are two alkyl groups, multipler = di CH3 CH2 O CH2 CH3 = diethyl ether NOMENCLATURE Ex. CH3 O CH3 • Functional group is a simple ether, therefore use alkyl alkyl ether 1. Both substituents are C1 alkane therefore alkyl = methyl 2. Since there are two alkyl groups, multipler = di CH3 O CH3 = dimethyl ether MECHANISMS 1. Sulfuric acid dissociates 2. The alcohol's oxygen atom is protonated with an acidbase reaction, forming an oxonium ion 3. The oxonium ion decomposes 4. The oxonium ion liberates a proton to create the ether Ethers can be synthesized in standard SN2 conditions by coupling an alkoxide with a haloalkane or sulfonate ester. The alcohol that supplies the electron rich alkoxide is used as the solvent, as well as dimethyl sulfoxide (DMSO) MECHANISMS Ethers are stable, non-reactive compounds. The linkage is stable towards bases, oxidizing agents, and reducing agents. Ethers undergo just one kind of basic chemical reaction: cleavage by acids. Cleavage takes place under vigorous conditions: concentrated acids and high temperatures. or the reaction can occur by way of an SN2 mechanism. The reaction mechanism depends upon the reaction conditions and the structure of the ether. A primary alkyl group tends to undergo SN2 displacement EXAMPLES In alcohols, one of the two bonds to the oxygen atom involves hydrogen and one involves carbon. Such compounds are called ethers. For example, dimethyl ether is isomeric with ethanol, and methyl ethyl ether is isomeric with propanol. Crown Ethers: These cyclic polyethers can form chemical complexes with metal cations (such as lithium, sodium, and potassium cations), thus holding the cations in solution. The size of the interior of the crown ether determines the size of the cation it can solvate EXAMPLES What differentiates a halogenated ether from other types of ethers is the substitution of one or more hydrogen atoms with a halogen atom. Halogen atoms include fluorine, chlorine, bromine, and iodine. Halogenated ethers have the advantages of being non-flammable as well as less toxic Isoflurane halogenated ether than earlier general anesthetics. REAL WORLD IMPORTANCE Diethyl Ether Uses: highly flammable liquid, solvent and an anesthetic. Fuel: used as the starting fluid for diesel and gasoline based engines. Solvent: Many scientist have been known to use ether as a solvent because of its limited solubility in water. This makes sets it up to preform liquid to liquid extractions. Anesthetic: Ether has been used worldwide by doctors when preforming anesthesia on patients. A WORLD WITHOUT ETHER? Ether has proven to be a very useful and important in the progress of man. Without Ether the vast majority of petroleum based engines would have no kick start. Also without Ether anesthetic use in the late 1800s, modern day anesthetics may be drastically dif ferent. QUESTIONS What is typical structure of an ether? If both groups are simple alkyl groups, then the ether is usually named as _____ _____ _____? If the two alkyl groups are the same, then it's a ______ _____? What is the one basic chemical reaction ethers undergo? Cleavage only occurs under what two conditions? ANSWERS Ethers always have to have an oxygen in the center. They can have hydrogen and carbon bound off of each side but the oxygen must remain in the middle at an angle of 110 degrees. Alkyl Alkyl Ether Dialkyl Ether Clevage Concentrated Acids and High Temperatures. http://www.chem.ucalgary.ca/cours es/351/orgnom/ethers/ethers01.html http://www.cliffsnotes.com/study_gui de/Ethers.topicArticleId23297,articleId-23273.html http://www.newworldencyclope dia.org/entry/Ether http://chemed.chem.wisc.edu/chemp aths/GenChem-Textbook/Ethers922.html Work Cited