tailieunhanh - Lecture Organic chemistry: Chapter 14 - L. G. Wade, Jr.

Chapter 14 introduce to ethers, epoxides, and sulfides. After completing this chapter, students will be able to: Draw and name ethers and heterocyclic ethers, including epoxides; explain the trends in their boiling points, solubilities, and solvent properties; determine the structures of ethers from their spectra, and explain their characteristic absorptions and fragmentations;. | Chapter 14 ã 2010, Prentice Hall Organic Chemistry, 7th Edition L. G. Wade, Jr. Ethers, Epoxides, and Sulfides Chapter 14 Ethers Formula is R—O—R¢ where R and R¢ are alkyl or aryl. Symmetrical or unsymmetrical O C H 3 C H 3 O C H 3 Chapter 14 Structure and Polarity Oxygen is sp3 hybridized. Bent molecular geometry. C—O—C angles is 110°. Polar C—O bonds. Dipole moment of D. Chapter 14 Boiling Points Similar to alkanes of comparable molecular weight. Chapter 14 Hydrogen Bond Acceptor Ethers cannot hydrogen-bond with other ether molecules. Molecules that cannot hydrogen-bond intermolecularly have a lower boiling point. Ether molecules can hydrogen-bond with water and alcohol molecules. Chapter 14 Solvation of Ions with Ether An ionic substance such as lithium iodide is moderately soluble in ethers because the small lithium cation is strongly solvated by the ether’s lone pairs of electrons. Unlike alcohols, ether cannot serve as hydrogen-bond . | Chapter 14 ã 2010, Prentice Hall Organic Chemistry, 7th Edition L. G. Wade, Jr. Ethers, Epoxides, and Sulfides Chapter 14 Ethers Formula is R—O—R¢ where R and R¢ are alkyl or aryl. Symmetrical or unsymmetrical O C H 3 C H 3 O C H 3 Chapter 14 Structure and Polarity Oxygen is sp3 hybridized. Bent molecular geometry. C—O—C angles is 110°. Polar C—O bonds. Dipole moment of D. Chapter 14 Boiling Points Similar to alkanes of comparable molecular weight. Chapter 14 Hydrogen Bond Acceptor Ethers cannot hydrogen-bond with other ether molecules. Molecules that cannot hydrogen-bond intermolecularly have a lower boiling point. Ether molecules can hydrogen-bond with water and alcohol molecules. Chapter 14 Solvation of Ions with Ether An ionic substance such as lithium iodide is moderately soluble in ethers because the small lithium cation is strongly solvated by the ether’s lone pairs of electrons. Unlike alcohols, ether cannot serve as hydrogen-bond donors, so they do not solvate small anions well. Chapter 14 Ether Complexes Grignard reagents: Complexation of an ether with a Grignard reagent stabilizes the reagent and helps keep it in solution. Electrophiles: The ethers nonbonding electrons stabilize the borane (BH3). Chapter 14 Crown Ether Complexes Crown ethers can complex metal cations inside the ring. The size of the cation will determine the size of the ring needed. Complexation by crown ethers often allows polar inorganic salts to dissolve in nonpolar organic solvents. Chapter 14 Common Names of Ethers Name the two alkyl groups attached to the oxygen and add the word ether. Name the groups in alphabetical order Symmetrical: Use dialkyl or just alkyl. diethyl ether or ethyl ether t-butyl methyl ether or methyl t-butyl ether C H 3 C H 2 O C H 2 C H 3 C H 3 O C C H 3 C H 3 C H 3 Chapter 14 IUPAC Names The more complex alkyl group is the alkane name. The small group (with the oxygen) becomes an

• Hoá học
• Organic chemistry
• Lecture Organic chemistry
• Hóa học hữu cơ
• Electronic Structure
• Hydrogen bond acceptor
• Polarity of ethers