0.2 Structure of Carboxylic Acid Derivatives 20.2 STRUCTURE OF CARBOXYLIC ACID DERIVATIVES Figure 20. 1 shows the structures and electrostatic potentials of the various derivatives of acetic acid-acetyl chloride, acetic anhydride, ethyl acetate, acetamide, and acetonitrile Like the other carbonyl-containing compounds that weve studied, acyl chlorides, anhy drides, esters, and amides all have a planar arrangement of bonds to the carbonyl group An important structural feature of acyl chlorides, anhydrides, esters, and amides is that the atom attached to the acyl group bears an unshared pair of electrons that can interact with the carbonyl TT system, as shown in Figure 20.2 This electron delocalization can be represented in resonance terms by contributions from the following resonance structures →R Electron release from the substituent stabilizes the carbonyl group and decreases its elec- trophilic character. The extent of this electron delocalization depends on the electron 00 CHaCOCCI CHaCSCHCH Acetyl chloride Acetic anhydride Ethyl thioacetate FIGURE 20.1 The structures and electrostatic of va CH,CH CH3 CNH2 rivatives of acetic acid. thes Ethyl acetate Acetonitnle Learning By Modeling. Back Forward Main MenuToc Study Guide ToC Student o MHHE Website20.2 STRUCTURE OF CARBOXYLIC ACID DERIVATIVES Figure 20.1 shows the structures and electrostatic potentials of the various derivatives of acetic acid–acetyl chloride, acetic anhydride, ethyl acetate, acetamide, and acetonitrile. Like the other carbonyl-containing compounds that we’ve studied, acyl chlorides, anhy￾drides, esters, and amides all have a planar arrangement of bonds to the carbonyl group. An important structural feature of acyl chlorides, anhydrides, esters, and amides is that the atom attached to the acyl group bears an unshared pair of electrons that can interact with the carbonyl system, as shown in Figure 20.2. This electron delocalization can be represented in resonance terms by contributions from the following resonance structures: Electron release from the substituent stabilizes the carbonyl group and decreases its elec￾trophilic character. The extent of this electron delocalization depends on the electron￾R X C  O R X C  O R X C O 20.2 Structure of Carboxylic Acid Derivatives 777 CH3CCl CH3COCCH3 CH3CSCH2CH3 CH3COCH2CH3 CH3CNH2 O O O O O O O O O O O O CH3CPN Acetyl chloride Acetic anhydride Ethyl thioacetate Ethyl acetate Acetamide Acetonitrile FIGURE 20.1 The structures and electrostatic potential maps of various de￾rivatives of acetic acid. These models may be viewed on Learning By Modeling. Back Forward Main Menu TOC Study Guide TOC Student OLC MHHE Website